Applied Physics Letters: All Topics

Plasmonic enhancement of photocurrent in MoS field-effect-transistor

Jiadan Lin, Hai Li, Hua Zhang, and Wei Chen
The two-dimensional material, molybdenum disulfide (MoS), has attracted considerable attention for numerous applications in optoelectronics. Here, we demonstrate a plasmonic enhancement of photocurrent in MoS field-effect-transistor decorated with gold nanoparticles, with significantly enhanced phot ... [Appl. Phys. Lett. 102, 203109 (2013)] published Tue May 21, 2013.

Catalyst size dependent growth of Pd-catalyzed one-dimensional InAs nanostructures

Hong-Yi Xu, Ya-Nan Guo, Zhi-Ming Liao, Wen Sun, Qiang Gao et al.
In this study, Pd was used as catalyst to grow one-dimensional InAs nanostructures on GaAs (111) substrates in order to explore the growth mechanism and the effect of non-gold catalysts in growing epitaxial III-V nanostructures. With detailed morphological, structural, and chemical characterizations ... [Appl. Phys. Lett. 102, 203108 (2013)] published Tue May 21, 2013.

Large surface-enhanced Raman scattering from self-assembled gold nanosphere monolayers

Jake Fontana, John Livenere, Francisco J. Bezares, Joshua D. Caldwell, Ronald Rendell et al.
We demonstrate an average surface-enhanced Raman scattering enhancement on the order of 10 from benzenethiol molecules using self-assembled, macroscopic, and tunable gold nanosphere monolayers on non-templated substrates. The self-assembly of the nanosphere monolayers uses a simple and efficient tec ... [Appl. Phys. Lett. 102, 201606 (2013)] published Tue May 21, 2013.

Conductive atomic force microscopy study of single molecule electron transport through the Azurin-gold nanoparticle system

Samuele Raccosta, Chiara Baldacchini, Anna Rita Bizzarri, and Salvatore Cannistraro
Transduction of biorecognition events into electrical signals through integration of single redox metalloproteins in bioelectronic nanodevices requires both a reliable electrical contact between the biomolecule and the metallic electrode and an efficient overall conduction mechanism. These condition ... [Appl. Phys. Lett. 102, 203704 (2013)] published Tue May 21, 2013.

Modeling of trap assisted interfacial charge transfer in dye sensitized solar cells

Jeevan Nepal, Seyyed Sadegh Mottaghian, Matt Biesecker, and Mahdi Farrokh Baroughi
This paper presents a model for charge transport in dye sensitized solar cells based on the physics of electron capture, electron emission, oxidation, and reduction processes mediated by deep interfacial trap states at TiO/dye/electrolyte interfaces. This model suggests that electron back injection ... [Appl. Phys. Lett. 102, 203503 (2013)] published Tue May 21, 2013.

Interfacial chemistry and valence band offset between GaN and AlO studied by X-ray photoelectron spectroscopy

T. L. Duan, J. S. Pan, and D. S. Ang
The interface region between Ga-face n-type GaN and AlO dielectric (achieved via atomic-layer deposition or ALD) is investigated by X-ray photoelectron spectroscopy (XPS). An increase in the Ga-O to Ga-N bond intensity ratio following AlO deposition implies that the growth of an interfacial gallium ... [Appl. Phys. Lett. 102, 201604 (2013)] published Tue May 21, 2013.

Stimulated Raman scattering cascade spanning the wavelength range of 523 to 1750 nm using a graded-index multimode optical fiber

Hamed Pourbeyram, Govind P. Agrawal, and Arash Mafi
We report on the generation of a Raman cascade spanning the wavelength range of 523 to 1750 nm wavelength range in a standard telecommunication graded-index multimode optical fiber. Despite the highly multimode nature of the pump, the Raman peaks are generated in specific modes of the fiber, confirm ... [Appl. Phys. Lett. 102, 201107 (2013)] published Tue May 21, 2013.

Simulations of magnetic hysteresis loops for dual layer recording media

T. J. Fal, M. L. Plumer, J. P. Whitehead, J. I. Mercer, J. van Ek et al.
A Kinetic Monte-Carlo algorithm is applied to examine MH loops of dual-layer magnetic recording media at finite temperature and long time scales associated with typical experimental measurements. In contrast with standard micromagnetic simulations, which are limited to the ns-[mu]s time regime, our ... [Appl. Phys. Lett. 102, 202404 (2013)] published Tue May 21, 2013.

Impact-ionization field-effect-transistor based biosensors for ultra-sensitive detection of biomolecules

Deblina Sarkar, Harald Gossner, Walter Hansch, and Kaustav Banerjee
The phenomenon of impact-ionization is proposed to be leveraged for a novel biosensor design scheme for highly efficient electrical detection of biological species. Apart from self-consistent numerical simulations, an analytical formalism is also presented to provide physical insight into the workin ... [Appl. Phys. Lett. 102, 203110 (2013)] published Tue May 21, 2013.

Two-photon nanolithography of positive photoresist thin film with ultrafast laser direct writing

Hong-Zhong Cao, Mei-Ling Zheng, Xian-Zi Dong, Feng Jin, Zhen-Sheng Zhao et al.
The authors investigate two-photon nanolithography of a positive photoresist thin film and the influence factor of spatial resolution. A spatial resolution of 85 nm, about one-ninth of the laser wavelength at 780 nm, has been realized by using commercial positive AZ P4620 photoresist. Theoretical an ... [Appl. Phys. Lett. 102, 201108 (2013)] published Tue May 21, 2013.

Two-beam spin noise spectroscopy

Yuriy V. Pershin, Valeriy A. Slipko, Dibyendu Roy, and Nikolai A. Sinitsyn
We propose a method of two-beam spin noise spectroscopy to test the spin transport at equilibrium via analysis of correlations between time-shifted spin fluctuations at different space locations. This method allows one to determine the strength of spin-orbit interaction and spin relaxation time and ... [Appl. Phys. Lett. 102, 202405 (2013)] published Tue May 21, 2013.

The first-principles study of oscillating rectifying performance in nanoribbon-chain-carbon nanotube junctions

Ming Qiu and K. M. Liew
Electronic transport properties of armchair graphene nanoribbon and capped carbon nanotube junctions, covalently bridged by carbon atomic chains with different numbers of carbon atoms, are investigated. The first-principles calculations based on non-equilibrium Green's functions with the density-fun ... [Appl. Phys. Lett. 102, 203106 (2013)] published Tue May 21, 2013.

Laser triggered Z-pinch broadband extreme ultraviolet source for metrology

I. Tobin, L. Juschkin, Y. Sidelnikov, F. O'Reilly, P. Sheridan et al.
We compare the extreme ultraviolet emission characteristics of tin and galinstan (atomic %: Ga: 78.35, In: 14.93, Sn: 6.72) between 10 nm and 18 nm in a laser-triggered discharge between liquid metal-coated electrodes. Over this wavelength range, the energy conversion efficiency for galinstan is app ... [Appl. Phys. Lett. 102, 203504 (2013)] published Tue May 21, 2013.

Hole-blocking titanium-oxide/silicon heterojunction and its application to photovoltaics

Sushobhan Avasthi, William E. McClain, Gabriel Man, Antoine Kahn, Jeffrey Schwartz et al.
In contrast to the numerous reports on narrow-bandgap heterojunctions on silicon, such as strained SiGe on silicon, there have been very few accounts of wide-bandgap semiconducting heterojunctions on silicon. Here, we present a wide-bandgap heterojunctionbetween titanium oxide and crystalline silico ... [Appl. Phys. Lett. 102, 203901 (2013)] published Tue May 21, 2013.

A micro-structured ion-implanted magnonic crystal

Bjorn Obry, Philipp Pirro, Thomas Bracher, Andrii V. Chumak, Julia Osten et al.
We investigate spin-wave propagation in a microstructured magnonic-crystal waveguide fabricated by localized ion implantation. The irradiation caused a periodic variation in the saturation magnetization along the waveguide. As a consequence, the spin-wave transmission spectrum exhibits a set of freq ... [Appl. Phys. Lett. 102, 202403 (2013)] published Tue May 21, 2013.

In-situ X-ray diffraction combined with scanning AC nanocalorimetry applied to a FeNi thin-film sample

John M. Gregoire, Kechao Xiao, Patrick J. McCluskey, Darren Dale, Gayatri Cuddalorepatta et al.
We combine the characterization techniques of scanning AC nanocalorimetry and x-ray diffraction to study phase transformations in complex materials system. Micromachined nanocalorimeters have excellent performance for high-temperature and high-scanning-rate calorimetry measurements. Time-resolved X- ... [Appl. Phys. Lett. 102, 201902 (2013)] published Tue May 21, 2013.

Generation of high-flux attosecond extreme ultraviolet continuum with a 10 TW laser

Y. Wu, E. Cunningham, H. Zang, J. Li, M. Chini et al.
We report a laser system that delivers 15 fs pulses with 200 mJ energy at a 10 Hz repetition rate. The broadband spectrum extending from 700 nm to 900 nm was obtained by seeding a two-stage Ti:sapphire chirped-pulse power amplifier with sub-mJ white-light pulses from a gas-filled hollow-core fiber. ... [Appl. Phys. Lett. 102, 201104 (2013)] published Tue May 21, 2013.

Nanodiamond vacuum field emission device with gate modulated triode characteristics

S. H. Hsu, W. P. Kang, S. Raina, and J. H. Huang
A three-electrode nanodiamond vacuum field emission (VFE) device with gate modulated triode characteristics is developed by integrating nanodiamond emitter with self-aligned silicon gate and anode, employing a mold transfer technique in conjunction with chemical vapor deposition of nanodiamond. Trio ... [Appl. Phys. Lett. 102, 203105 (2013)] published Tue May 21, 2013.

Excitation power dependence of the Purcell effect in photonic crystal microcavity lasers with quantum wires

J. Canet-Ferrer, I. Prieto, G. Munoz-Matutano, L. J. Martinez, L. E. Munoz-Camuniez et al.
The Purcell effect dependence on the excitation power is studied in photonic crystal microcavity lasers embedding InAs/InP quantum wires. In the case of non-lasing modes, the Purcell effect has low dependence on the optical pumping, attributable to an exciton dynamics combining free and localized ex ... [Appl. Phys. Lett. 102, 201105 (2013)] published Tue May 21, 2013.

Parasitic nonlinearities in photon pair generation via integrated spontaneous four-wave mixing: Critical problem or distraction?

L. G. Helt, M. J. Steel, and J. E. Sipe
We consider integrated photon pair sources based on spontaneous four-wave mixing and derive expressions for the pump powers at which various nonlinear processes become relevant for a variety of source materials and structures. These expressions serve as rules of thumb in identifying reasonable param ... [Appl. Phys. Lett. 102, 201106 (2013)] published Tue May 21, 2013.

Scaling law for energy bandgap and effective electron mass in graphene nano mesh

Jonghoon Lee, Ajit K. Roy, Jennifer L. Wohlwend, Vikas Varshney, John B. Ferguson et al.
For the energy bandgap of semiconducting graphene nano mesh (GNM), chirality dependent scaling rules have been proposed so far. Based on extensive tight binding studies and simple geometric arguments, we report that Pedersen scaling governs not only the energy bandgap but also the effective mass of ... [Appl. Phys. Lett. 102, 203107 (2013)] published Tue May 21, 2013.

Gold-titania interface toughening and thermal conductance enhancement using an organophosphonate nanolayer

Philippe K. Chow, Y. Cardona Quintero, Peter O'Brien, P. Hubert Mutin, Michael Lane et al.
We demonstrate that a mercaptan-terminated organophosphonate nanolayer at gold-titania interfaces can give rise to two- to three-fold enhancement in the interfacial fracture toughness and thermal conductance. Electron spectroscopy reveals that interfacial delamination occurs at the metal-molecule in ... [Appl. Phys. Lett. 102, 201605 (2013)] published Tue May 21, 2013.

Conductive and transparent superhydrophobic films on various substrates by in situ deposition

Guiyuan Wang, Weixin Liang, Ben Wang, Yabin Zhang, Jing Li et al.
Conductive and transparent superhydrophobic coatings on poly (ethylene terephthalate), polystyrene (PS), glass slides were fabricated by a facile and low-cost in situ deposition method, forming a binary structure by nanocomposites. The results showed that the maximum transmittance of the coated PS s ... [Appl. Phys. Lett. 102, 203703 (2013)] published Tue May 21, 2013.

Thermal conductivity of single biological cells and relation with cell viability

Byoung Kyoo Park, Namwoo Yi, Jaesung Park, and Dongsik Kim
This paper presents measurements of effective thermal conductivity of single biological cells (HeLa, NIH-3T3 J2, and hepatocyte). Such cellular-level measurements have not been performed previously, due to the small size (~10 pl) of cells. The measurement uses the three-omega method with a nanoscale ... [Appl. Phys. Lett. 102, 203702 (2013)] published Mon May 20, 2013.

High-resolution chemical imaging of gold nanoparticles using hard x-ray ptychography

R. Hoppe, J. Reinhardt, G. Hofmann, J. Patommel, J.-D. Grunwaldt et al.
We combine resonant scattering with (ptychographic) scanning coherent diffraction microscopy to determine the chemical state of gold nanoparticles with high spatial resolution. Ptychographic images of the sample are recorded for a series of energies around the gold L absorption edge. From these data ... [Appl. Phys. Lett. 102, 203104 (2013)] published Mon May 20, 2013.

Dopant migration effects in terahertz quantum cascade lasers

C. Deutsch, H. Detz, M. Krall, M. Brandstetter, T. Zederbauer et al.
We demonstrate that dopant migration and the resulting impurity scattering can strongly influence the performance of GaAs/AlGaAs terahertz quantum cascade lasers. A nominally symmetric structure allows us to compare the negative and positive bias behavior of the very same device. Dopants, migrated t ... [Appl. Phys. Lett. 102, 201102 (2013)] published Mon May 20, 2013.

A study of oxidative stress induced by non-thermal plasma-activated water for bacterial damage

Qian Zhang, Yongdong Liang, Hongqing Feng, Ruonan Ma, Ying Tian et al.
Ar/O (2%) cold plasma microjet was used to create plasma-activated water (PAW). The disinfection efficacy of PAW against Staphylococcus aureus showed that PAW can effectively disinfect bacteria. Optical emission spectra and oxidation reduction potential results demonstrated the inactivation is attri ... [Appl. Phys. Lett. 102, 203701 (2013)] published Mon May 20, 2013.

Diagnosis of femtosecond plasma filament by channeling microwaves along the filament

Mostafa Alshershby, Yu Ren, Jiang Qin, Zuoqiang Hao, and Jingquan Lin
We introduce a simple, fast, and non-intrusive experimental method to obtain the basic parameters of femtosecond laser-generated plasma filament. The method is based on the channeling of microwaves along both a plasma filament and a well-defined conducting wire. By comparing the detected microwaves ... [Appl. Phys. Lett. 102, 204101 (2013)] published Mon May 20, 2013.

Pressure-sensing based on photothermally coupled operation of micromechanical beam resonator

D. H. Kim, E. J. Lee, M. R. Cho, C. S. Kim, Y. D. Park et al.
Here, we demonstrate the pressure-sensing scheme based on the photothermal effect in the miniaturized beam resonator in the moderate pressure range. Since the resonance frequency of the small beam resonator under thermal stress can be easily modulated by the convective cooling of the gas molecules, ... [Appl. Phys. Lett. 102, 203502 (2013)] published Mon May 20, 2013.

Publisher's Note: Selective detection of tetrahedral units in amorphous GeTe-based phase change alloys using Ge L3-edge x-ray absorption near-edge structure spectroscopy [Appl. Phys. Lett. 102, 111904 (2013)]

M. Krbal, A. V. Kolobov, P. Fons, K. V. Mitrofanov, Y. Tamenori et al.
Abstract not available. [Appl. Phys. Lett. 102, 209901 (2013)] published Mon May 20, 2013.

All-optical measurement of vertical charge carrier transport in mid-wave infrared InAs/GaSb type-II superlattices

B. V. Olson, L. M. Murray, J. P. Prineas, M. E. Flatte, J. T. Olesberg et al.
Time-resolved differential transmission measurements were used to investigate vertical charge carrier transport in mid-wave infrared InAs/GaSb type-II superlattices (T2SLs). By optically generating excess carriers near one end of the mid-wave T2SL and measuring the transit time to a thin, lower-band ... [Appl. Phys. Lett. 102, 202101 (2013)] published Mon May 20, 2013.

Enhanced photon-generated carrier extraction from Si nanostructure under additional infrared light irradiation

Wei Yu, Yanmei Xu, Huimin Li, Jin Wang, Guangsheng Fu et al.
Recombination and trapping effect in quantum dots are large barriers to efficient photon-generated carrier extraction. In this paper, Infrared (IR)-assisted carrier extraction in a Si/SiO multiple quantum well is demonstrated. Operated at reverse bias, enhanced photoresponse from 300 to 700 nm is ob ... [Appl. Phys. Lett. 102, 201101 (2013)] published Mon May 20, 2013.

Investigation of the release of Si from SiO during the formation of manganese/ruthenium barrier layers

A. P. McCoy, P. Casey, J. Bogan, C. Byrne, and G. Hughes
The thermodynamic and structural stability of ruthenium-manganese diffusion barriers on SiO is assessed. A ~2 nm film composed of partially oxidized manganese (MnO where x < 1) was deposited on a 3 nm thick Ru film and the Mn-MnO/Ru/SiO structure was subsequently thermally annealed. X-ray photoelect ... [Appl. Phys. Lett. 102, 201603 (2013)] published Mon May 20, 2013.

Spectral dispersion of ultrafast optical limiting in Coumarin-120 by white-light continuum Z-scan

Benoy Anand, Nivya Roy, S. Siva Sankara Sai, and Reji Philip
Measurement of the wavelength dispersion of optical limiting in materials can provide invaluable information useful for laser safety device applications. However, it can be a tedious task when conventional tunable laser sources like the optical parametric amplifier are employed for excitation. Here ... [Appl. Phys. Lett. 102, 203302 (2013)] published Mon May 20, 2013.

Experimental realization of reflection-type periodic diffraction correlation imaging

Hu Li, Yinzuo Zhang, Jianhong Shi, and Guihua Zeng
We demonstrate the periodic diffraction correlation imaging (PDCI) of a reflective object using only one array detector to achieve simpler setups of ghost imaging: no beam-splitter is needed, and only one detector is utilized. Multiple reference beams with a same pattern of the signal beam are gener ... [Appl. Phys. Lett. 102, 201901 (2013)] published Mon May 20, 2013.

Single InAs quantum dot coupled to different environments in one wafer for quantum photonics

Ying Yu, Xiang-Jun Shang, Mi-Feng Li, Guo-Wei Zha, Jian-Xing Xu et al.
Self assembled small InAs quantum dots (SQDs) were formed in various densities and environments using gradient InAs deposition on a non-rotating GaAs substrate. Two SQD environments (SQD I and SQD II) were characterized. SQD I featured SQDs surrounded by large QDs, and SQD II featured individual SQD ... [Appl. Phys. Lett. 102, 201103 (2013)] published Mon May 20, 2013.

Fabrication and scanning tunneling microscopy characterization of suspended monolayer graphene on periodic Si nanopillars

Xin Zhao, Xiaofang Zhai, Aidi Zhao, Bing Wang, and J. G. Hou
We present the fabrication and scanning tunneling microscopy (STM) characterization of suspended monolayer graphene (SMG) on periodic Si nanostructure. Monolayer graphene (MG) was grown on Cu foils by chemical vapor deposition (CVD) and transferred onto a Si substrate with etched array of periodic n ... [Appl. Phys. Lett. 102, 201602 (2013)] published Mon May 20, 2013.

Core-shell magnetic exchange model for CoO nanowires

Lan Chen, Yurong Yang, and Xiangkang Meng
First-principles calculations are performed to investigate the magnetic properties of CoO nanowires. A microscopic core-shell magnetic exchange model, including intra-core, intra-plane, core-shell (core-plane), and plane-plane (shell-shell) interactions, is proposed. The sign of magnetic exchange co ... [Appl. Phys. Lett. 102, 203102 (2013)] published Mon May 20, 2013.

Magnetic tunnel junctions with AlO tunnel barriers prepared by atomic layer deposition

Xinfei Liu and Jing Shi
Uniform AlO tunnel barriers are fabricated with atomic layer deposition. The tunneling magnetoresistance in optimized AlO-based magnetic tunnel junctions is studied as a function of temperature in comparison with SrTiO-based tunnel devices having the same LaSrMnO and Co electrodes. The junction resi ... [Appl. Phys. Lett. 102, 202401 (2013)] published Mon May 20, 2013.

Laser-scanning Doppler photoacoustic microscopy based on temporal correlation

Wei Song, Wenzhong Liu, and Hao F. Zhang
We present a methodology to measure absolute flow velocity using laser-scanning photoacoustic microscopy. To obtain the Doppler angle, the angle between ultrasonic detection axis and flow direction, we extracted the distances between the transducer and three adjacent scanning points along the flow a ... [Appl. Phys. Lett. 102, 203501 (2013)] published Mon May 20, 2013.

Resonance enhancement of difference-frequency generation through localized surface plasmon excitation

Xu Fang, Shin Yaginuma, Wakana Kubo, and Takuo Tanaka
We report the experimental observation of difference-frequency generation in gold nanoparticles under localized surface plasmon excitation. A zero-delay peak is detected in the differential transmission signal for a gold nanoparticle film with a MgF overlayer, showing that the energy transfer from p ... [Appl. Phys. Lett. 102, 203101 (2013)] published Mon May 20, 2013.

Exchange-spring like magnetic behavior of the tetragonal Heusler compound MnFeGa as a candidate for spin-transfer torque

Teuta Gasi, Ajaya K. Nayak, Jurgen Winterlik, Vadim Ksenofontov, Peter Adler et al.
We report structural, magnetic, and Mossbauer studies of the Heusler compound MnFeGa. Theoretical calculations predict that a tetragonal phase in MnFeGa could be an interesting candidate for spin torque transfer applications due to the presence of perpendicular magnetic anisotropy. Experimentally, w ... [Appl. Phys. Lett. 102, 202402 (2013)] published Mon May 20, 2013.

Negative compressibility observed in graphene containing resonant impurities

X. L. Chen, L. Wang, W. Li, Y. Wang, Y. H. He et al.
We observed negative compressibility in monolayer graphene containing resonant impurities under different magnetic fields. Hydrogenous impurities were introduced into graphene by electron beam (e-beam) irradiation. Resonant states located in the energy region of 0.04 eV around the charge neutrality ... [Appl. Phys. Lett. 102, 203103 (2013)] published Mon May 20, 2013.

Photoactive self-assembled monolayers for optically switchable organic thin-film transistors

Michael Salinas and Marcus Halik
We investigate the photoconductive and photovoltaic effects in organic thin-film transistors with thin hybrid dielectrics composed of aluminum oxide and self-assembled monolayers (SAMs). By using SAM molecules with an electro-optical functionality tuning of the photoinduced charge transfer at the in ... [Appl. Phys. Lett. 102, 203301 (2013)] published Mon May 20, 2013.

Young-Lippmann equation revisited for nano-suspensions

Daniel Orejon, Khellil Sefiane, and Martin E. R. Shanahan
We present the results of an experimental study investigating electrowetting effects in nano-suspension drops. Wetting of sessile drops of titanium oxide (TiO) nano-particles dispersed in deionised water was studied under a DC voltage potential. The presence of nano-particles is found to further enh ... [Appl. Phys. Lett. 102, 201601 (2013)] published Mon May 20, 2013.

Superconductor/ferromagnet heterostructures exhibit potential for significant reduction of hysteretic losses

Philipp Kruger, Francesco Grilli, Michal VojenCiak, Victor M. R. Zermeno, Eduard Demencik et al.
First experimental observations of the ferromagnetic shielding effect in high-T superconducting coated conductors were carried out. Experimental results were compared to simulations calling upon finite-element calculations based on the H-formulation of Maxwell equations to model superconducting stri ... [Appl. Phys. Lett. 102, 202601 (2013)] published Mon May 20, 2013.

Inactivation of Microcystis aeruginosa using dielectric barrier discharge low-temperature plasma

Sichuan Pu, Jierong Chen, Gang Wang, Xiaoyong Li, and Yun Ma
The efficiency of Microcystis aeruginosa plasma inactivation was investigated using dielectric barrier discharge low-temperature plasma. The inactivation efficiency was characterized in terms of optical density. The influence of electrical and physicochemical parameters on M. aeruginosa inactivation ... [Appl. Phys. Lett. 102, 194105 (2013)] published Fri May 17, 2013.

Sub-picosecond and nanometer scale dynamics of aluminum target surface heated by ultrashort laser pulse

F. Deneuville, B. Chimier, D. Descamps, F. Dorchies, S. Hulin et al.
The possibility of measuring surface hydrodynamics at picosecond and nanometer scales by using a time resolved optical interfero-polarimeter is demonstrated. This method is applied to observe the surface position of aluminum target heated by ultrashort laser pulse. Numerical simulations of the surfa ... [Appl. Phys. Lett. 102, 194104 (2013)] published Fri May 17, 2013.

Direct folding simulation of a long helix in explicit water

Ya Gao, Xiaoliang Lu, Lili Duan, Dawei Zhang, Ye Mei et al.
A recently proposed Polarizable Hydrogen Bond (PHB) method has been employed to simulate the folding of a 53 amino acid helix (PDB ID 2KHK) in explicit water. Under PHB simulation, starting from a fully extended structure, the peptide folds into the native state as confirmed by measured time evoluti ... [Appl. Phys. Lett. 102, 193706 (2013)] published Fri May 17, 2013.

Solitonic Dirac fermion wave guide networks on topological insulator surfaces

Rene Hammer, Christian Ertler, and Walter Potz
Magnetic texturing on the surface of a topological insulator allows the design of wave guide networks and beam splitters for domain-wall Dirac fermions. Guided by simple analytic arguments, we model a Dirac domain-wall fermion interferometer consisting of two parallel pathways imprinted by solitonic ... [Appl. Phys. Lett. 102, 193514 (2013)] published Fri May 17, 2013.

Impact of Ti doping in SmO dielectric on electrical characteristics of a-InGaZnO thin-film transistors

Fa-Hsyang Chen, Jim-Long Her, Somnath Mondal, Meng-Ning Hung, and Tung-Ming Pan
We investigated the impact of Ti doping in the SmO dielectric on the electrical stress-induced instability in amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs). With increasing stress time in a-IGZO TFT devices, a small initial positive shift followed by a negative shift of t ... [Appl. Phys. Lett. 102, 193515 (2013)] published Fri May 17, 2013.

DropBot: An open-source digital microfluidic control system with precise control of electrostatic driving force and instantaneous drop velocity measurement

Ryan Fobel, Christian Fobel, and Aaron R. Wheeler
We introduce DropBot: an open-source instrument for digital microfluidics (http://microfluidics.utoronto.ca/dropbot). DropBot features two key functionalities for digital microfluidics: (1) real-time monitoring of instantaneous drop velocity (which we propose is a proxy for resistive forces), and (2 ... [Appl. Phys. Lett. 102, 193513 (2013)] published Fri May 17, 2013.

Solution-processed ZnO nanoparticle-based transistors via a room-temperature photochemical conversion process

Yen-Hung Lin, Hendrik Faber, Stephan Rossbauer, and Thomas D. Anthopoulos
We report on zinc oxide (ZnO) nanoparticle-based transistors in which the solution-processed semiconducting layers are post-treated using UV light irradiation instead of high temperature annealing. Field-effect transistors based on these ZnO nanoparticle films exhibit n-channel characteristics with ... [Appl. Phys. Lett. 102, 193516 (2013)] published Fri May 17, 2013.

Optimization of graphene dry etching conditions via combined microscopic and spectroscopic analysis

Mariana C. Prado, Deep Jariwala, Tobin J. Marks, and Mark C. Hersam
Single-layer graphene structures and devices are commonly defined using reactive ion etching and plasma etching with O or Ar as the gaseous etchants. Although optical microscopy and Raman spectroscopy are widely used to determine the appropriate duration of dry etching, additional characterization w ... [Appl. Phys. Lett. 102, 193111 (2013)] published Fri May 17, 2013.

FeO-nanoparticles within porous silicon: Magnetic and cytotoxicity characterization

P. Granitzer, K. Rumpf, Y. Tian, G. Akkaraju, J. Coffer et al.
The magnetic properties of porous silicon/FeO composites are investigated with respect to the adjustability of the blocking temperature along with an evaluation of any size-dependent changes in cytocompatibility. FeO-nanoparticles have been infiltrated within mesoporous silicon, resulting in a syste ... [Appl. Phys. Lett. 102, 193110 (2013)] published Fri May 17, 2013.

A thermal logic device based on fluid-solid interfaces

Sohail Murad and Ishwar K. Puri
Thermal rectification requires that thermal conductivity not be a separable function of position and temperature. Investigators have considered inhomogeneous solids to design thermal rectifiers but manipulations of solid lattices are energy intensive. We propose a thermal logic device based on asymm ... [Appl. Phys. Lett. 102, 193109 (2013)] published Fri May 17, 2013.

Polymernanocrystal hybrid photodetectors with planar heterojunctions designed strategically to yield a high photoconductive gain

Tae Kyu An, Chan Eon Park, and Dae Sung Chung
We demonstrate an approach to enhancing the photoresponsivity of a polymer photodetector (PPD). Both conventional bulk heterojunction (BHJ) and planar heterojunction (PHJ) PPDs were fabricated considering that the interface between a CdSe nanocrystal and a polymer can create photoconductive gain. A ... [Appl. Phys. Lett. 102, 193306 (2013)] published Fri May 17, 2013.

Topography-guided spreading and drying of 6,13-bis(triisopropylsilylethynyl)-pentacene solution on a polymer insulator for the field-effect mobility enhancement

Chang-Min Keum, Jin-Hyuk Bae, Min-Hoi Kim, Hea-Lim Park, Marcia M. Payne et al.
We report on the enhancement of the field-effect mobility of solution-processed 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-pentacene) by unidirectional topography (UT) of an inkjet-printed polymer insulator. The UT leads to anisotropic spreading and drying of the TIPS-pentacene droplet and e ... [Appl. Phys. Lett. 102, 193307 (2013)] published Fri May 17, 2013.

Substrate-independent catalyst-free synthesis of high-purity BiSe nanostructures

Jerome T. Mlack, Atikur Rahman, Gary L. Johns, Kenneth J. T. Livi, and Nina Markovic
We describe a catalyst-free vapor-solid synthesis of bismuth selenide (BiSe) nanostructures at ambient pressure with H as carrier gas. The nanostructures were synthesized on glass, silicon, and mica substrates and the method yields a variety of nanostructures: nanowires, nanoribbons, nanoplatelets, ... [Appl. Phys. Lett. 102, 193108 (2013)] published Fri May 17, 2013.

Optimized inverted polymer solar cells incorporating CsCO-doped C60 as electron transport layer

A. Barbot, B. Lucas, C. Di Bin, B. Ratier, and M. Aldissi
An efficient charge transfer between co-sublimed cesium carbonate (CsCO) and fullerene C60 provides an n-type material exhibiting an electrical conductivity above 1 S/cm. This type of doped layers can be used in organic optoelectronic devices to reduce ohmic losses at organic-electrode interfaces. W ... [Appl. Phys. Lett. 102, 193305 (2013)] published Fri May 17, 2013.

Depth resolved studies of SrTiO defects using x-ray excited optical luminescence and cathodoluminescence

R. A. Rosenberg, Y. Choi, K. Vijayalakshmi, M. Kareev, J. Tchakhalian et al.
We have performed comparative depth-dependent x-ray excited optical luminescence (XEOL) and depth resolved cathodoluminescence spectroscopy measurements in order to understand the native point defect distribution in three SrTiO samples. Both techniques found surface segregation of Ti defects, but ap ... [Appl. Phys. Lett. 102, 192910 (2013)] published Fri May 17, 2013.

Effect of polarization on intersubband transition in AlGaN/GaN multiple quantum wells

G. Chen, Z. L. Li, X. Q. Wang, C. C. Huang, X. Rong et al.
Intersubband transitions (ISBT) of AlGaN/GaN multiple quantum wells (MQWs) with wavelength towards atmospheric window (35 [mu]m) have been investigated. A Ga-excess epitaxial method is used in the molecular beam epitaxy leading to ultra-sharp interface and negligible elements inter-diffusion. The ab ... [Appl. Phys. Lett. 102, 192109 (2013)] published Fri May 17, 2013.

Mechanical stress influence on electronic transport in low-k SiOC dielectric single damascene capacitor

Ya-Liang Yang, Tai-Fa Young, Ting-Chang Chang, Fu-Yen Shen, Jia-Haw Hsu et al.
We fabricate a SiOC comb structure capacitor device, and apply mechanical stress into samples by bending. From I-V fitting, we obtain the energy barrier lowering beta, and conclude that the electron transport in single damascene capacitor is due to Poole-Frenkel emission. Tension yields a decrease o ... [Appl. Phys. Lett. 102, 192912 (2013)] published Fri May 17, 2013.

Ultra-smooth epitaxial Ge grown on Si(001) utilizing a thin C-doped Ge buffer layer

J. Mantey, W. Hsu, J. James, E. U. Onyegam, S. Guchhait et al.
Here, we present work on epitaxial Ge films grown on a thin buffer layer of C doped Ge (Ge:C). The growth rate of Ge:C is found to slow over time and is thus unsuitable for thick (>20 nm) layers. We demonstrate Ge films from 10 nm to >150 nm are possible by growing pure Ge on a thin Ge:C buffer. It ... [Appl. Phys. Lett. 102, 192111 (2013)] published Fri May 17, 2013.

Chemical identification of luminescence due to Sn and Sb in ZnO

J. Cullen, D. Byrne, K. Johnston, E. McGlynn, and M. O. Henry
We show that the I line in ZnO photoluminescence is associated with Sn impurities. The evidence comes from material implanted with radioactive Ag, which decays through Cd and In to stable Sn, and Ag, which decays through the same chain to stable Sb. Supporting evidence is provided by ZnO:Sn prepared ... [Appl. Phys. Lett. 102, 192110 (2013)] published Fri May 17, 2013.

Controlling magnetism of multiferroic (BiLa)FeCrO thin films by epitaxial and crystallographic orientation strain

Amit Khare, Abhishek Singh, S. S. Prabhu, and D. S. Rana
Effects of the tensile and compressive epitaxial strain and the crystallographic orientations on the structural and magnetic properties of (BiLa)FeCrO (BLFCO) films were studied. The BLFCO (001) films (30 nm and 70 nm) were deposited on various single crystal substrates having lattice mismatch with ... [Appl. Phys. Lett. 102, 192911 (2013)] published Fri May 17, 2013.

Ultra-thin free-standing single crystalline silicon membranes with strain control

A. Shchepetov, M. Prunnila, F. Alzina, L. Schneider, J. Cuffe et al.
We report on fabrication and characterization of ultra-thin suspended single crystalline flat silicon membranes with thickness down to 6 nm. We have developed a method to control the strain in the membranes by adding a strain compensating frame on the silicon membrane perimeter to avoid buckling aft ... [Appl. Phys. Lett. 102, 192108 (2013)] published Fri May 17, 2013.

Visible-light photoresponse of AlN-based film bulk acoustic wave resonator

C. J. Zhou, Y. Yang, Y. Shu, H. L. Cai, T. L. Ren et al.
Visible-light photoresponse of an AlN-based film bulk acoustic wave resonator (FBAR) is demonstrated. It is found that the FBAR exhibits a resonant frequency downshift under purple light illumination and the magnitude of the frequency downshift increases as the power density increases within the ran ... [Appl. Phys. Lett. 102, 191914 (2013)] published Fri May 17, 2013.

Carrier dynamics in linearly and step graded bandgap ZnCdO structures

M. Trunk, A. Galeckas, V. Venkatachalapathy, A. Yu. Azarov, and A. Yu. Kuznetsov
We report on the time-resolved photoluminescence studies of step-like and linearly graded bandgap ZnCdO (x = 0% 60%) structures. The key carrier transport properties essential to the concept of variable bandgap absorbers are addressed, including radiative and nonradiative lifetime, diffusion and dr ... [Appl. Phys. Lett. 102, 191916 (2013)] published Fri May 17, 2013.

Dislocation and antiphase domain free microscale GaAs crystals grown on SiO from (001) Si nano-areas

C. Renard, N. Cherkasin, A. Jaffre, L. Vincent, A. Michel et al.
The epitaxial lateral overgrowth of microscale GaAs crystals on a 0.6 nm thick SiO layer from nanoscale Si seeds is investigated in order to develop GaAs monolithic hetero-epitaxy onto (001) Si. The nucleation from small width openings enables to avoid the emission of misfit dislocations and the for ... [Appl. Phys. Lett. 102, 191915 (2013)] published Fri May 17, 2013.

Electron microscopy investigations of purity of AlN interlayer in AlGaN/GaN heterostructures grown by plasma assisted molecular beam epitaxy

D. V. Sridhara Rao, Anubha Jain, Sushil Lamba, K. Muraleedharan, and R. Muralidharan
The electron microscopy was used to characterize the AlN interlayer in AlGaN/AlN/GaN heterostructures grown by plasma assisted molecular beam epitaxy (PAMBE). We show that the AlN interlayer grown by PAMBE is without gallium and oxygen incorporation and the interfaces are coherent. The AlN interlaye ... [Appl. Phys. Lett. 102, 191604 (2013)] published Fri May 17, 2013.

Defect segregation at grain boundary and its impact on photovoltaic performance of CuInSe

Wan-Jian Yin, Yelong Wu, Rommel Noufi, Mowafak Al-Jassim, and Yanfa Yan
Defect segregations at grain boundaries (GBs) of polycrystalline thin-film absorber are crucial to solar cell performance. The Sigma3(114) GBs in CuInSe (CIS) have been studied through first-principle calculations. We reveal that the intrinsic CIS GBs produce deep gap states, which act as nonradiati ... [Appl. Phys. Lett. 102, 193905 (2013)] published Thu May 16, 2013.

Insulated multinozzle system for electrohydrodynamic atomization in the simple-jet mode

L. L. F. Agostinho, C. U. Yurteri, J. Wartena, S. P. Brouwer, E. C. Fuchs et al.
In this study, a multinozzle electrohydrodynamic atomization device was designed and studied for electrosprays in the simple-jet mode. Results have shown that the proposed device produces droplets with similar diameter in all nozzles, that the electric field creates a unique dispersion of the charge ... [Appl. Phys. Lett. 102, 194103 (2013)] published Thu May 16, 2013.

Intracellular temperature mapping with fluorescence-assisted photoacoustic-thermometry

Liang Gao, Chi Zhang, Chiye Li, and Lihong V. Wang
Measuring intracellular temperature is critical to understanding many cellular functions but still remains challenging. Here, we present a techniquefluorescence-assisted photoacoustic thermometry (FAPT)for intracellular temperature mapping applications. To demonstrate FAPT, we monitored the intracel ... [Appl. Phys. Lett. 102, 193705 (2013)] published Thu May 16, 2013.

A micro seismometer based on molecular electronic transducer technology for planetary exploration

Hai Huang, Bryce Carande, Rui Tang, Jonathan Oiler, Dmitri Zaitsev et al.
This letter describes an implementation of micromachined seismometer based on molecular electronic transducer (MET) technology. As opposed to a solid inertial mass, MET seismometer senses the movement of liquid electrolyte relative to fixed electrodes. The employment of micro-electro-mechanical syst ... [Appl. Phys. Lett. 102, 193512 (2013)] published Thu May 16, 2013.

Electronic transport and Schottky barrier heights of p-type CuAlO Schottky diodes

Yow-Jon Lin (林祐仲), Jie Luo (羅傑), and Hao-Che Hung (洪浩哲)
A CuAlO Schottky diode was fabricated and investigated using current density-voltage (J-V) and capacitance-voltage (C-V) methods. It is shown that the barrier height (qphi) determined from J-V measurements is lower than that determined from C-V measurements and qphi determined from C-V measurements ... [Appl. Phys. Lett. 102, 193511 (2013)] published Thu May 16, 2013.

Effect of proton irradiation on AlGaN/GaN micro-Hall sensors

A. Abderrahmane, S. Koide, H. Okada, H. Takahashi, S. Sato et al.
The magnetoelectric properties of AlGaN/GaN micro-Hall effect sensors were studied after 380 keV proton irradiation. After irradiation the current-voltage measurements, stability of the magnetic sensitivity of the sensors, and the sheet electron density were degraded with a dramatic decrease of the ... [Appl. Phys. Lett. 102, 193510 (2013)] published Thu May 16, 2013.

Theoretical model of superconducting spintronic SIsFS devices

S. V. Bakurskiy, N. V. Klenov, I. I. Soloviev, V. V. Bol'ginov, V. V. Ryazanov et al.
Motivated by recent progress in the development of cryogenic memory compatible with single flux quantum (SFQ) circuits, we have performed a theoretical study of magnetic SIsFS Josephson junctions, where S is a bulk superconductor, s is a thin superconducting film, F is a metallic ferromagnet, and I ... [Appl. Phys. Lett. 102, 192603 (2013)] published Thu May 16, 2013.

Electrical performance of monolayer MoS field-effect transistors prepared by chemical vapor deposition

Matin Amani, Matthew L. Chin, A. Glen Birdwell, Terrance P. O'Regan, Sina Najmaei et al.
Molybdenum disulfide (MoS) field effect transistors (FET) were fabricated on atomically smooth large-area single layers grown by chemical vapor deposition. The layer qualities and physical properties were characterized using high-resolution Raman and photoluminescence spectroscopy, scanning electron ... [Appl. Phys. Lett. 102, 193107 (2013)] published Thu May 16, 2013.

Bessel-beam-written nanoslit arrays and characterization of their optical response

R. Sahin, Y. Morova, E. Simsek, and S. Akturk
Nanoslit arrays are fabricated on thin metal film coated glass slides using femtosecond laser pulses with Bessel beam profiles. The optical properties of the fabricated structures with different periodicities are characterized with transmission spectroscopy. Experimental results reveal the existence ... [Appl. Phys. Lett. 102, 193106 (2013)] published Thu May 16, 2013.

Probing hot electron transport across an epitaxial Schottky interface of SrRuO/Nb:SrTiO

S. Roy, A. M. Kamerbeek, K. G. Rana, S. Parui, and T. Banerjee
SrRuO (SRO), a conducting transition metal oxide, is commonly used for engineering domains in BiFeO. Oxide devices can be envisioned by integrating SRO with an oxide semiconductor as Nb doped SrTiO (Nb:STO). Using a three-terminal device configuration, we study vertical transport in a SRO/Nb:STO dev ... [Appl. Phys. Lett. 102, 192909 (2013)] published Thu May 16, 2013.

Pyroelectric electron emission from nanometer-thick films of PbZrTiO

Patrick C. Fletcher, Vengadesh Kumara R. Mangalam, Lane W. Martin, and William P. King
We report pyroelectric emission from PbZrTiO (PZT) thin films on nanometer-sharp tips. The epitaxial PZT films are 30 nm thick and grown directly on single-crystal silicon tips. Pyroelectric emission occurs for heating rates of >=50 degrees C/min in a 20 V/[mu]m external field. The emission current ... [Appl. Phys. Lett. 102, 192908 (2013)] published Thu May 16, 2013.

Reaching 10 ms single photon lifetimes for superconducting aluminum cavities

Matthew Reagor, Hanhee Paik, Gianluigi Catelani, Luyan Sun, Christopher Axline et al.
Three-dimensional microwave cavities have recently been combined with superconducting qubits in the circuit quantum electrodynamics architecture. These cavities should have less sensitivity to dielectric and conductor losses at surfaces and interfaces, which currently limit the performance of planar ... [Appl. Phys. Lett. 102, 192604 (2013)] published Thu May 16, 2013.

Spin torque transistor revisited

Takahiro Chiba, Gerrit E. W. Bauer, and Saburo Takahashi
We theoretically study the operation of a 4-terminal device consisting of two lateral thin-film spin valves that are coupled by a magnetic insulator such as yttrium iron garnet via the spin transfer torque. By magnetoelectronic circuit theory we calculate the current voltage characteristics and find ... [Appl. Phys. Lett. 102, 192412 (2013)] published Thu May 16, 2013.

Large magnetocaloric effect and refrigerant capacity near room temperature in as-cast GdGeSiSn compounds

A. Magnus G. Carvalho, J. C. G. Tedesco, M. J. M. Pires, M. E. Soffner, A. O. Guimaraes et al.
Large values of isothermal entropy change (DeltaS) and refrigerant capacity have been found in GdGeSiSn compounds. Values of the order of 20 J kg K for DeltaS were obtained in as-cast samples when submitted to a magnetic field variation of 2 T. First-order-magneto-structural transition is induced by ... [Appl. Phys. Lett. 102, 192410 (2013)] published Thu May 16, 2013.

Monolithic integration of light-emitting diodes and power metal-oxide-semiconductor channel high-electron-mobility transistors for light-emitting power integrated circuits in GaN on sapphire substrate

Z. Li, J. Waldron, T. Detchprohm, C. Wetzel, R. F. Karlicek, Jr. et al.
We report the demonstration of monolithically integrated light-emitting diodes (LEDs) and power metal-oxide-semiconductor channel high-electron-mobility transistors (HEMTs) in GaN. The structure comprised a direct epitaxial integration of layers typical for a GaN-based LED grown directly on top of t ... [Appl. Phys. Lett. 102, 192107 (2013)] published Thu May 16, 2013.

Avalanche transition with super-bandwidth magnetic field response in (LaBi)CaMnO

Zhengcai Xia, Borong Chen, Yuying Wu, Zhongwen Ouyang, Yue Wu et al.
The magnetic and electrical behaviors of an optimizing doping (LaBi)CaMnO were investigated. An avalanche transition with a super-bandwidth of magnetic field response, in which the magnetic field sweep rate ranging from 10 Oe/s to 4886.8 T/s, was observed in the manganite. The insensitivity of the c ... [Appl. Phys. Lett. 102, 192408 (2013)] published Thu May 16, 2013.

Tailoring spin-orbit torque in diluted magnetic semiconductors

Hang Li, Xuhui Wang, Fatih Dogan, and Aurelien Manchon
We study the spin orbit torque arising from an intrinsic linear Dresselhaus spin-orbit coupling in a single layer III-V diluted magnetic semiconductor. We investigate the transport properties and spin torque using the linear response theory, and we report here: (1) a strong correlation exists betwee ... [Appl. Phys. Lett. 102, 192411 (2013)] published Thu May 16, 2013.

Ferromagnetic bubble clusters in YCaMnO thin films

Jeehoon Kim, N. Haberkorn, Suenne Kim, L. Civale, P. C. Dowden et al.
We studied the ferromagnetic domains and the presence of phase coexistence in a YCaMnO thin film with a combination of magnetic force microscopy and magnetization measurements. Our results show that the spin glass-like behavior, reported previously for this system, could be attributed to frustrated ... [Appl. Phys. Lett. 102, 192409 (2013)] published Thu May 16, 2013.

Tungsten-incorporation induced red-shift in the bandgap of gallium oxide thin films

E. J. Rubio and C. V. Ramana
Tungsten (W) incorporated GaO films were produced by co-sputter deposition. W-concentration was varied by the applied sputtering-power. The structure and optical properties of W-incorporated GaO films were evaluated using X-ray diffraction, scanning electron microscopy, and spectrophotometric measur ... [Appl. Phys. Lett. 102, 191913 (2013)] published Thu May 16, 2013.

Investigation of energy transfer and charge trapping in dye-doped organic light-emitting diodes by magneto-electroluminescence measurement

Qiming Peng, Na Gao, Weijun Li, Ping Chen, Feng Li et al.
We investigated the energy transfer and charge trapping (CT) in dye-doped organic light-emitting devices by using the magneto-electroluminescence as a tool. An intra-molecular charge-transfer fluorescent material N,N-diphenyl-4-(9-phenylnaphtho-[2,3-c][1,2,5]thiadiazol-4-yl)aniline was selected as t ... [Appl. Phys. Lett. 102, 193304 (2013)] published Thu May 16, 2013.

Polymer-dispersed liquid crystal doped with carbon nanotubes for dimethyl methylphosphonate vapor-sensing application

Yu-Tse Lai, Jui-Chang Kuo, and Yao-Joe Yang
This paper proposes a sensitive gas sensor composed of polymer-dispersed liquid crystal (PDLC) for dimethyl methylphosphonate (DMMP) detection. The sensing element comprises a PDLC sensing film doped with carbon nanotubes (CNT-PDLC) and a planar interdigital electrode pair. The concentration of DMMP ... [Appl. Phys. Lett. 102, 191912 (2013)] published Thu May 16, 2013.

Revisiting the In-clustering question in InGaN through the use of aberration-corrected electron microscopy below the knock-on threshold

Kamal H. Baloch, Aaron C. Johnston-Peck, Kim Kisslinger, Eric A. Stach, and Silvija GradeCak
The high intensity of light emitted in InGaN/GaN heterostructures has been generally attributed to the formation of indium-rich clusters in InGaN quantum wells (QWs). However, there is significant disagreement about the existence of such clusters in as-grown InGaN QWs. We employ atomically resolved ... [Appl. Phys. Lett. 102, 191910 (2013)] published Thu May 16, 2013.

Electron and hole mobilities at a Si/SiO interface with giant valley splitting

Yoshitaka Niida, Kei Takashina, Yukinori Ono, Akira Fujiwara, and Yoshiro Hirayama
We examine the electron mobility and hole mobility at the Si/buried oxide (BOX) interface at which the valley splitting of the electron system is strongly enhanced, and compare the values observed to those at a standard Si/thermal oxide (T-SiO) interface in the same silicon-on-insulator device. In c ... [Appl. Phys. Lett. 102, 191603 (2013)] published Thu May 16, 2013.

19 [mu]m quantum cascade infrared photodetectors

Shen-Qiang Zhai, Jun-Qi Liu, Xue-Jiao Wang, Ning Zhuo, Feng-Qi Liu et al.
Two InP based InGaAs/InAlAs photovoltaic quantum cascade detectors operating at peak wavelengths of 18 [mu]m and 19 [mu]m using different electronic transport mechanisms are reported. A longitudinal optical phonon extraction stair combined with energy mini-steps are employed for electron transport, ... [Appl. Phys. Lett. 102, 191120 (2013)] published Thu May 16, 2013.

Phonon and electron transport through GeSbTe films and interfaces bounded by metals

Jaeho Lee, Elah Bozorg-Grayeli, SangBum Kim, Mehdi Asheghi, H.-S. Philip Wong et al.
While atomic vibrations dominate thermal conduction in the amorphous and face-centered cubic phases of GeSbTe, electrons dominate in the hexagonal closed-packed (hcp) phase. Here we separate the electron and phonon contributions to the interface and volume thermal resistances for the three phases us ... [Appl. Phys. Lett. 102, 191911 (2013)] published Thu May 16, 2013.

Dominant deuteron acceleration with a high-intensity laser for isotope production and neutron generation

A. Maksimchuk, A. Raymond, F. Yu, G. M. Petrov, F. Dollar et al.
Experiments on the interaction of an ultra-short pulse laser with heavy-water, ice-covered copper targets, at an intensity of 2 x 10 W/cm, were performed demonstrating the generation of a pure deuteron beam with a divergence of 20 degrees , maximum energy of 8 MeV, and a total of 3 x 10 deuterons wi ... [Appl. Phys. Lett. 102, 191117 (2013)] published Thu May 16, 2013.

High quality factor nonpolar GaN photonic crystal nanocavities

Tzeng-Tsong Wu, Sheng-Yun Lo, Huei-Min Huang, Che-Wei Tsao, Tien-Chang Lu et al.
High quality factor a-plane nonpolar GaN two-dimensional photonic crystal (PC) nanocavities on r-plane sapphire substrates have been demonstrated. Nonpolar GaN PC nanocavities on a thin membrane structure were realized by using e-beam lithography to define the PC patterns and focused-ion beam millin ... [Appl. Phys. Lett. 102, 191116 (2013)] published Thu May 16, 2013.

Tunable 1.62 [mu]m near infrared few-cycle pulse generation by filamentation

S. Driever, D. Bigourd, N. Fedorov, M. Cornet, M. Arnold et al.
We present results on tunable few-cycle laser pulses generated in the near infrared region obtained by filamentation in a krypton cell combined with group velocity dispersion compensation in fused silica. We obtain a spectral broadening of a factor ~23 over the entire spectral domain studied. The ce ... [Appl. Phys. Lett. 102, 191119 (2013)] published Thu May 16, 2013.

ZnO-SiO solar-blind photodetectors on flexible polyethersulfone substrate with organosilicon buffer layer

Wei-Chih Lai, Jiun-Ting Chen, and Ya-Yu Yang
The ZnO-SiO nanocomposite solar-blind metal-semiconductor-metal photodetectors (PDs) on flexible polyethersulfone (PES) with an organosilicon (SiO(CH)) buffer layer improved the 10 V-biased responsivity of PDs illuminated wavelength of 240 nm from 0.75 A/W (without SiO(CH) buffer layer) to 3.86 A/W ... [Appl. Phys. Lett. 102, 191115 (2013)] published Thu May 16, 2013.

Fabrication and characterization of a room-temperature ZnO polariton laser

Feng Li, L. Orosz, O. Kamoun, S. Bouchoule, C. Brimont et al.
A ZnO planar optical microcavity displaying room-temperature polariton lasing over a wide range of cavity-exciton detunings has been fabricated. The cavity combines optimum crystalline quality, given by a ZnO single-crystal substrate, and optimum photonic quality, obtained by the use of two dielectr ... [Appl. Phys. Lett. 102, 191118 (2013)] published Thu May 16, 2013.

InGaN/GaN light-emitting diode with a polarization tunnel junction

Zi-Hui Zhang, Swee Tiam Tan, Zabu Kyaw, Yun Ji, Wei Liu et al.
We report InGaN/GaN light-emitting diodes (LED) comprising in situ integrated p-GaN/InGaN/n-GaN polarization tunnel junctions. Improved current spreading and carrier tunneling probability were obtained in the proposed device architecture, leading to the enhanced optical output power and external qua ... [Appl. Phys. Lett. 102, 193508 (2013)] published Wed May 15, 2013.

Coupling of InAs/InP quantum dots to the plasmon resonance of In nanoparticles grown by metal-organic vapor phase epitaxy

Jiayue Yuan, C. Y. Jin, Matthias Skacel, Adam Urbanczyk, Tian Xia et al.
We report strongly modified optical emission of InAs/InP quantum dots (QDs) coupled to the surface plasmon resonance (SPR) of In nanoparticles grown by metal-organic vapor phase epitaxy. With increasing In deposition time, the In nanoparticle size increases and the SPR redshifts significantly. When ... [Appl. Phys. Lett. 102, 191111 (2013)] published Wed May 15, 2013.

Broadband saturable absorption and optical limiting in graphene-polymer composites

S. Husaini, J. E. Slagle, J. M. Murray, S. Guha, L. P. Gonzalez et al.
Nonlinear optical properties of a graphene-polyvinyl alcohol composite are studied using an irradiance-scan setup. The measurements are carried out at 785 nm and 1064 nm in the nanosecond and picoseconds temporal regimes, respectively. It is shown that the output fluence readily clamps with increasi ... [Appl. Phys. Lett. 102, 191112 (2013)] published Wed May 15, 2013.

Low-field induced giant magnetocaloric effect in TmCuAl compound

Zhao-Jun Mo, Jun Shen, Li-Qin Yan, Jian-Feng Wu, Li-Chen Wang et al.
A giant low field reversible magnetocaloric effect has been observed in TmCuAl compound around 4 K, which is the boiling point of helium. The maximum value of magnetic entropy change (DeltaS) and adiabatic temperature change (DeltaT) is 17.2 J/Kg K and 4.6 K without thermal and field hysteresis loss ... [Appl. Phys. Lett. 102, 192407 (2013)] published Wed May 15, 2013.

Effects of high energy x ray and proton irradiation on lead zirconate titanate thin films' dielectric and piezoelectric response

Y. Bastani, A. Y. Cortes-Pena, A. D. Wilson, S. Gerardin, M. Bagatin et al.
The effects of irradiation by X rays and protons on the dielectric and piezoelectric response of highly (100)-textured polycrystalline Pb(ZrTi)O (PZT) thin films have been studied. Low-field dielectric permittivity, remanent polarization, and piezoelectric d response all degraded with exposure to ra ... [Appl. Phys. Lett. 102, 192906 (2013)] published Wed May 15, 2013.

Non-volatile switching characteristics in wet-deposited AgSe/GeSe double layers for resistive random access memory applications

Ki-Hyun Nam, Jang-Han Kim, Won-Ju Cho, and Hong-Bay Chung
The resistance switching characteristics of resistive random access memory (ReRAM) based on amorphous GeSe thin films have been demonstrated by using Al/AgSe/GeSe/Pt structure. The AgSe layer that serves as the metal ionic source of GeSe switching medium was formed by a very simple wet-deposition pr ... [Appl. Phys. Lett. 102, 192106 (2013)] published Wed May 15, 2013.

Anomalous circular photogalvanic effect of the spin-polarized two-dimensional electron gas in MgZnO/ZnO heterostructures at room temperature

J. X. Duan, N. Tang, J. D. Ye, F. H. Mei, K. L. Teo et al.
A spin-related photocurrent with swirly distribution and anomalous dependence of the total spin-related photocurrent on the incident angle were observed on spin-polarized two-dimensional gas in a MgZnO/ZnO heterostructure under illumination of circular polarized light at room temperature. The ferrom ... [Appl. Phys. Lett. 102, 192405 (2013)] published Wed May 15, 2013.

Energy resolved X-ray grating interferometry

T. Thuering, W. C. Barber, Y. Seo, F. Alhassen, J. S. Iwanczyk et al.
Although compatible with polychromatic radiation, the sensitivity in X-ray phase contrast imaging with a grating interferometer is strongly dependent on the X-ray spectrum. We used an energy resolving detector to quantitatively investigate the dependency of the noise from the spectral bandwidth and ... [Appl. Phys. Lett. 102, 191113 (2013)] published Wed May 15, 2013.

Spatially-resolved spectroscopic measurements of E 0.57 eV traps in AlGaN/GaN high electron mobility transistors

D. W. Cardwell, A. Sasikumar, A. R. Arehart, S. W. Kaun, J. Lu et al.
Simultaneous temperature-dependent measurements of resistance transients (RTs) and spatially resolved surface potential transients were made after bias switching on AlGaN/GaN high electron mobility transistors (HEMTs). We find an E 0.57 eV trap, previously correlated with HEMT degradation, located ... [Appl. Phys. Lett. 102, 193509 (2013)] published Wed May 15, 2013.

Erratum: Mapping microwave field distributions via the spin Hall effect [Appl. Phys. Lett. 101, 252406 (2012)]

Vincent Vlaminck, Helmut Schultheiss, John E. Pearson, Frank Y. Fradin, Sam D. Bader et al.
Abstract not available. [Appl. Phys. Lett. 102, 199901 (2013)] published Wed May 15, 2013.

Polyamorphism and origin of spatially heterogeneous dynamics in network-forming liquids under compression: Insight from visualization of molecular dynamics data

N. V. Hong, M. T. Lan, N. T. Nhan, and P. K. Hung
Polyamorphism and dynamical heterogeneities in network-forming liquids (SiO, GeO, AlO) at 3200 K and in a wide pressure range are investigated by molecular dynamics simulation. Results show that their structure comprises three structural phases: TO-, TO-, and TO-phases (T = Si, Ge, or Al). The size ... [Appl. Phys. Lett. 102, 191908 (2013)] published Wed May 15, 2013.

Single-peak narrow-bandwidth mid-infrared thermal emitters based on quantum wells and photonic crystals

Takuya Inoue, Menaka De Zoysa, Takashi Asano, and Susumu Noda
We experimentally demonstrate single-peak narrow-bandwidth thermal emission with a quality factor (Q factor) of more than 100 at a wavelength of 9.1 [mu]m. The emission is significantly suppressed at all other wavelengths. Our emitter is based on an intersubband transition in a multiple quantum well ... [Appl. Phys. Lett. 102, 191110 (2013)] published Wed May 15, 2013.

Probing the dynamic responses of individual actin filaments under fluidic mechanical stimulation via microfluidics

Chao-Min Cheng, Chung-Yao Yang, YongTae Kim, and Philip R. LeDuc
Herein, we demonstrate an easy-to-handle approach that employs a combination of microcurvilinear flow and fluorescence microscopy for probing the dynamic responses of individual synthesized actin filaments. We observed morphological changes of single actin filaments with different spatiotemporal res ... [Appl. Phys. Lett. 102, 193704 (2013)] published Wed May 15, 2013.

Thermal conductivity of low temperature grown vertical carbon nanotube bundles measured using the three-omega method

Sten Vollebregt, Sourish Banerjee, Kees Beenakker, and Ryoichi Ishihara
The thermal conductivity of as-grown vertical multi-walled carbon nanotubes (CNT) bundles fabricated at low temperature (500 degrees C) was measured using a vertical 3omega-method. For this, CNT were selectively grown inside an oxide opening and sandwiched between two metal electrodes. The validity ... [Appl. Phys. Lett. 102, 191909 (2013)] published Wed May 15, 2013.

How reliable are Hanle measurements in metals in a three-terminal geometry?

Oihana Txoperena, Marco Gobbi, Amilcar Bedoya-Pinto, Federico Golmar, Xiangnan Sun et al.
We test the validity of Hanle measurements in three-terminal devices by using aluminum (Al) and gold (Au). The obtained Hanle and inverted Hanle-like curves show an anomalous behavior. First, we measure Hanle signals 8 orders of magnitude larger than those predicted by standard theory. Second, the t ... [Appl. Phys. Lett. 102, 192406 (2013)] published Wed May 15, 2013.

Floating electrode electrowetting on hydrophobic dielectric with an SiO layer

Mehdi Khodayari, Benjamin Hahne, Nathan B. Crane, and Alex A. Volinsky
Floating electrode electrowetting is caused by dc voltage applied to a liquid droplet on the Cytop surface, without electrical connection to the substrate. The effect is caused by the charge separation in the floating electrode. A highly resistive thermally grown SiO layer underneath the Cytop enabl ... [Appl. Phys. Lett. 102, 192907 (2013)] published Wed May 15, 2013.

High-power low-divergence tapered quantum cascade lasers with plasmonic collimators

Romain Blanchard, Tobias S. Mansuripur, Burc Gokden, Nanfang Yu, Mikhail Kats et al.
We demonstrate a tapered quantum cascade laser with sloped side-walls emitting a high-brightness single-lobe beam at 8.1 [mu]m with a peak power of 4 W at room temperature. Using a combination of high and low reflectivity facet coatings, the power output is increased to 6.2 W while a high beam quali ... [Appl. Phys. Lett. 102, 191114 (2013)] published Wed May 15, 2013.

Microplate-compatible total internal reflection fluorescence microscopy for receptor pharmacology

Minghan Chen, Natalya V. Zaytseva, Qi Wu, Min Li, and Ye Fang
We report the use of total internal reflection fluorescence (TIRF) microscopy for analyzing receptor pharmacology and the development of a microplate-compatible TIRF imaging system. Using stably expressed green fluorescence protein tagged beta-adrenergic receptor as the reporter, we found that the a ... [Appl. Phys. Lett. 102, 193702 (2013)] published Tue May 14, 2013.

Biotin-streptavidin detection with a graphene-oxide supported radio-frequency resonator

Hyong Seo Yoon, Juhwan Lim, Sang Uk Son, Duck-Hwan Kim, Insang Song et al.
The detection of biotin-streptavidin binding was demonstrated by the resonance frequency measurement of a simple resonance circuit using graphene oxide dielectric. The resonance frequency was decreased to the lower frequency range as biotin and streptavidin were bound to the graphene oxide film. Gra ... [Appl. Phys. Lett. 102, 193701 (2013)] published Tue May 14, 2013.

Self sensing feedback for dielectric elastomer actuators

Todd A. Gisby, Benjamin M. O'Brien, and Iain A. Anderson
Self sensing Dielectric Elastomer Actuator (DEA) artificial muscles will enable the creation of soft, lightweight robots with animal-like capabilities. We demonstrate a fast, accurate, and economic self sensing algorithm that enables an arbitrary voltage oscillation to be used to sense DEA capacitan ... [Appl. Phys. Lett. 102, 193703 (2013)] published Tue May 14, 2013.

Multiple current peaks in room-temperature atmospheric pressure homogenous dielectric barrier discharge plasma excited by high-voltage tunable nanosecond pulse in air

De-Zheng Yang (杨德正), Wen-Chun Wang (王文春), Shuai Zhang (张帅), Kai Tang (唐凯), Zhi-jie Liu (刘志杰) et al.
Room temperature homogenous dielectric barrier discharge plasma with high instantaneous energy efficiency is acquired by using nanosecond pulse voltage with 20200 ns tunable pulse width. Increasing the voltage pulse width can lead to the generation of regular and stable multiple current peaks in eac ... [Appl. Phys. Lett. 102, 194102 (2013)] published Tue May 14, 2013.

Impact of residual carbon on two-dimensional electron gas properties in AlGaN/GaN heterostructure

Jr-Tai Chen, Urban Forsberg, and Erik Janzen
High tuneability of residual carbon doping is developed in a hot-wall metalorganic chemical vapor deposition reactor. Two orders of temperature-tuned carbon concentration, from ~2 x 10 cm down to ~1 x 10 cm, can be effectively controlled in the growth of the GaN buffer layer. Excellent uniformit ... [Appl. Phys. Lett. 102, 193506 (2013)] published Tue May 14, 2013.

The effect of nitric oxide anneals on silicon vacancies at and very near the interface of 4H SiC metal oxide semiconducting field effect transistors using electrically detected magnetic resonance

C. J. Cochrane, P. M. Lenahan, and A. J. Lelis
We use three electrically detected magnetic resonance (EDMR) approaches to explore nitric oxide (NO) annealing in 4H SiC metal-oxide-semiconductor field-effect transistors (MOSFETs). One approach is sensitive to defects at the interface and those extending into the SiC. Two of these approaches are p ... [Appl. Phys. Lett. 102, 193507 (2013)] published Tue May 14, 2013.

A carbon nanotube based ammonia sensor on cotton textile

Jin-Woo Han, Beomseok Kim, Jing Li, and M. Meyyappan
A single-wall carbon nanotube (CNT) based ammonia (NH) sensor was implemented on a cotton yarn. Two types of sensors were fabricated: Au/sensing CNT/Au and conducting/sensing/conducting all CNT structures. Two perpendicular Au wires were designed to contact CNT-cotton yarn for metal-CNT sensor, wher ... [Appl. Phys. Lett. 102, 193104 (2013)] published Tue May 14, 2013.

Light absorption enhancement in closely packed Ge quantum dots

S. Mirabella, S. Cosentino, M. Failla, M. Miritello, G. Nicotra et al.
Multilayers of Ge quantum dots (QDs, 3 nm in diameter) embedded in SiO, separated by SiO barrier layer (3, 9, or 20 nm thick), have been synthesized by sputter deposition and characterized by transmission electron microscopy and light absorption spectroscopy. Quantum confinement affects the optical ... [Appl. Phys. Lett. 102, 193105 (2013)] published Tue May 14, 2013.

Very high dielectric strength for dielectric elastomer actuators in liquid dielectric immersion

Thanh-Giang La and Gih-Keong Lau
This letter reported that a dielectric elastomer actuator (3M VHB), which is immersed in a liquid dielectric bath, is enhanced tremendously in dielectric strength up to 800 MV/m, as compared to 450 MV/m for the actuator operated in air. The bath consists of silicone oil (Dow Corning Fluid 200 50cSt) ... [Appl. Phys. Lett. 102, 192905 (2013)] published Tue May 14, 2013.

Superconductivity induced by Se-doping in layered charge-density-wave system 1T-TaSSe

Y. Liu, R. Ang, W. J. Lu, W. H. Song, L. J. Li et al.
Layered 1T-TaSSe (0<=x<=2) single crystals have been systematically fabricated by a chemical vapor transport technique. Surprisingly, the superconductivity is induced by the Se doping. We demonstrate the appearance of a series of electronic states: the Mott phase melts into a nearly commensurate cha ... [Appl. Phys. Lett. 102, 192602 (2013)] published Tue May 14, 2013.

Advanced high-k gate dielectric amorphous LaGdO gated metal-oxide-semiconductor devices with sub-nanometer equivalent oxide thickness

S. P. Pavunny, P. Misra, R. Thomas, A. Kumar, J. Schubert et al.
Careful selection of pulsed laser deposition conditions was executed to achieve sub-nanometer EOT (equivalent oxide thickness) in amorphous LaGdO based high-k/metal gate stacks. The lowest EOTs attained were ~5.4 A and 8.4 A with and without quantum mechanical correction, respectively. The electrica ... [Appl. Phys. Lett. 102, 192904 (2013)] published Tue May 14, 2013.

Nb nano superconducting quantum interference devices with high spin sensitivity for operation in magnetic fields up to 0.5 T

R. Wolbing, J. Nagel, T. Schwarz, O. Kieler, T. Weimann et al.
We investigate electric transport and noise properties of microstrip-type submicron direct current superconducting quantum interference devices (dc SQUIDs) based on Nb thin films and overdamped Josephson junctions with a HfTi barrier. The SQUIDs were designed for optimal spin sensitivity S upon oper ... [Appl. Phys. Lett. 102, 192601 (2013)] published Tue May 14, 2013.

Intrinsic and extrinsic origins of low-frequency noise in GaAs/AlGaAs Schottky-gated nanostructures

Kenichi Hitachi, Takeshi Ota, and Koji Muraki
We study low-frequency noise in current passing through quantum point contacts fabricated from several GaAs/AlGaAs heterostructures with different layer structures and fabrication processes. In contrast to previous reports, there is no gate-dependent random telegraph noise (RTN) originating from tun ... [Appl. Phys. Lett. 102, 192104 (2013)] published Tue May 14, 2013.

Single-hole tunneling through a two-dimensional hole gas in intrinsic silicon

Paul C. Spruijtenburg, Joost Ridderbos, Filipp Mueller, Anne W. Leenstra, Matthias Brauns et al.
In this letter we report single-hole tunneling through a quantum dot in a two-dimensional hole gas, situated in a narrow-channel field-effect transistor in intrinsic silicon. Two layers of aluminum gate electrodes are defined on Si/SiO using electron-beam lithography. Fabrication and subsequent elec ... [Appl. Phys. Lett. 102, 192105 (2013)] published Tue May 14, 2013.

Storing magnetic information in IrMn/MgO/Ta tunnel junctions via field-cooling

D. Petti, E. Albisetti, H. Reichlova, J. Gazquez, M. Varela et al.
In this paper, we demonstrate that in Ta/MgO/IrMn tunneling junctions, containing no ferromagnetic elements, distinct metastable resistance states can be set by field cooling the devices from above the Neel temperature (T) along different orientations. Variations of the resistance up to 10% are foun ... [Appl. Phys. Lett. 102, 192404 (2013)] published Tue May 14, 2013.

Band engineering and growth of tensile strained Ge/(Si)GeSn heterostructures for tunnel field effect transistors

S. Wirths, A. T. Tiedemann, Z. Ikonic, P. Harrison, B. Hollander et al.
In this letter, we propose a heterostructure design for tunnel field effect transistors with two low direct bandgap group IV compounds, GeSn and highly tensely strained Ge in combination with ternary SiGeSn alloy. Electronic band calculations show that strained Ge, used as channel, grown on GeSn (x ... [Appl. Phys. Lett. 102, 192103 (2013)] published Tue May 14, 2013.

Perfect surface crystallization and parasitic structures in nonstoichiometric glass-ceramics: Micro-/nanoscopic aspects

Yoshihiro Takahashi, Yoshiki Yamazaki, Rie Ihara, and Takumi Fujiwara
Uniform and highly oriented crystalline layers with submillimeter thickness have been demonstrated recently by crystallization in nonstoichiometric precursor glass, i.e., perfectly surface-crystallized glass-ceramics (PSC-GCs). Although the origin of PSC in the SrOTiOSiO system was interpreted by th ... [Appl. Phys. Lett. 102, 191903 (2013)] published Tue May 14, 2013.

Dual-band asymmetric transmission of linear polarization in bilayered chiral metamaterial

Jinhui Shi, Xingchen Liu, Shengwu Yu, Tingting Lv, Zheng Zhu et al.
A bilayered chiral metamaterial is proposed and demonstrated to exhibit dual-band asymmetric transmission of linearly polarized electromagnetic waves in two opposite directions. Simulated and measured results show that the bilayered chiral metamaterial can achieve cross-polarization conversion with ... [Appl. Phys. Lett. 102, 191905 (2013)] published Tue May 14, 2013.

Micro-alloying and the toughness of glasses: Modeling with pinned particles

Ratul Dasgupta, Pankaj Mishra, Itamar Procaccia, and Konrad Samwer
The usefulness of glasses, and particularly of metallic glasses, in technological applications is often limited by their toughness, (which is defined as the area under the stress vs. strain curve before plastic yielding). Recently, toughness was found to increase significantly by the addition of sma ... [Appl. Phys. Lett. 102, 191904 (2013)] published Tue May 14, 2013.

Phonon transport in an initially twisted polyvinyl acetate nanofiber

Monrudee Liangruksa and Ishwar K. Puri
A reduction in phonon thermal conductivity enhances thermoelectric performance. One method to accomplish this is by applying mechanical stress to a nanostructure. We consider an initially twisted 20 nm polyvinyl acetate nanofiber undergoing torsion. Our analytical method uses the continuum approach ... [Appl. Phys. Lett. 102, 191907 (2013)] published Tue May 14, 2013.

Influence of SnO:F/ZnO:Al bi-layer as a front electrode on the properties of p-i-n amorphous silicon based thin film solar cells

Hyeongsik Park, Jaehyeong Lee, Heewon Kim, Doyoung Kim, Jayapal Raja et al.
The effect of aluminum doped zinc oxide film used between a fluorine doped tin oxide layer and a hydrogenated amorphous silicon carbide layer to improve the open circuit voltage (V) and fill factor (FF) for high efficiency thin film solar cells. The efficiency enhancement was accomplished by the ins ... [Appl. Phys. Lett. 102, 191602 (2013)] published Tue May 14, 2013.

Brillouin gain spectrum dependences on temperature and strain in erbium-doped optical fibers with different erbium concentrations

Mingjie Ding, Neisei Hayashi, Yosuke Mizuno, and Kentaro Nakamura
Brillouin Stokes power in erbium-doped optical fibers (EDFs) can be potentially controlled by pumping, but no report has been provided on its detailed characterization. In this study, as the first step toward this goal, the Brillouin gain spectra in EDFs with three different erbium concentrations (0 ... [Appl. Phys. Lett. 102, 191906 (2013)] published Tue May 14, 2013.

Probing embedded structural inhomogeneities in MgZnO alloys via selective resonant Raman scattering

Dinesh Thapa, Jesse Huso, Hui Che, Michelle Huso, John L. Morrison et al.
The issue of phase segregation, inherent to the MgZnO alloy system, was investigated via selective resonant Raman scattering. We demonstrate that it is a highly sensitive technique for the detection of embedded structural inhomogeneities. MgZnO thin-films with bandgaps that span the UV-range of 3.25 ... [Appl. Phys. Lett. 102, 191902 (2013)] published Tue May 14, 2013.

Terahertz transmission and sheet conductivity of randomly stacked multi-layer graphene

I. H. Baek, K. J. Ahn, B. J. Kang, S. Bae, B. H. Hong et al.
We investigate transmission characteristics and sheet conductivity of mono- to multi-layer graphene deposited on quartz in the terahertz (THz) frequency region. The free carrier absorption and Fabry-Perot interference between graphene layers give rise to nonlinear decrease of THz transmission from 7 ... [Appl. Phys. Lett. 102, 191109 (2013)] published Tue May 14, 2013.

Fabrication of two-dimensional InGaN/GaN photonic crystal structure using a modified nanosphere lithography technique

M. Athanasiou, T. K. Kim, B. Liu, R. Smith, and T. Wang
By means of combining a very cost-effective lift-off process and a nanosphere lithography technique, we have fabricated two dimensional (2D) photonic crystal (PhC) structures on an InGaN/GaN multiple quantum well structure. Significant enhancement in photoluminescence (PL) intensity has been observe ... [Appl. Phys. Lett. 102, 191108 (2013)] published Tue May 14, 2013.

Strong quantum-confined Stark effect from light hole related direct-gap transitions in Ge quantum wells

P. Chaisakul, D. Marris-Morini, M. S. Rouifed, J. Frigerio, G. Isella et al.
A strong quantum-confined Stark effect (QCSE) from light hole related transitions at the Gamma point (LH1-cGamma1) in Ge/SiGe multiple quantum wells is demonstrated from both photocurrent and optical transmission measurements. Our experimental results show a large and sharp optical absorption peak d ... [Appl. Phys. Lett. 102, 191107 (2013)] published Tue May 14, 2013.

Response to Comment on `Femtosecond laser-induced modification of potassium-magnesium silicate glasses: An analysis of structural changes by near edge x-ray absorption spectroscopy' [Appl. Phys. Lett. 102, 196101 (2013)]

Moritz Grehn, Falk Reinhardt, Jorn Bonse, Markus Eberstein, and Thomas Seuthe
Abstract not available. [Appl. Phys. Lett. 102, 196102 (2013)] published Tue May 14, 2013.

Comment on Femtosecond laser-induced modification of potassium-magnesium silicate glasses: An analysis of structural changes by near edge x-ray absorption spectroscopy [Appl. Phys. Lett. 100, 224101 (2012)]

Delphine Cabaret, Stephanie Rossano, and Nicolas Trcera
Abstract not available. [Appl. Phys. Lett. 102, 196101 (2013)] published Tue May 14, 2013.

Holographic storage and multiplexing in azopolyester blends using low energy pulses down to 2 ms

C. Berges, I. Javakhishvili, S. Hvilsted, C. Sanchez-Somolinos, and R. Alcala
Three different blends containing side-chain azobenzene polyesters and poly(methyl methacrylate) homopolymers have been prepared for recording volume holographic polarization gratings using 488 nm light pulses. The final azo content in the blends has been decreased down to 0.2 wt. %, and their morph ... [Appl. Phys. Lett. 102, 193303 (2013)] published Tue May 14, 2013.

Effects of bulk and interfacial charge accumulation on fill factor in organic solar cells

Bingbing Chen, Xianfeng Qiao, Chih-Ming Liu, Chen Zhao, Hsiu-Cheng Chen et al.
The effects of charge accumulation on fill factor (FF) are studied by using light intensity-dependent current-voltage and capacitance-voltage measurements based on poly-{bi(dodecyl)thiophene-thieno[3,4-c]pyrrole-4,6-dione}:1(3-methyloxycarbony1)propyl-1-phenyl [6,6] (PBTTPD:PCBM) solar cells. We fin ... [Appl. Phys. Lett. 102, 193302 (2013)] published Tue May 14, 2013.

Tube transport of water vapor with condensation and desorption

Annika Nordbo, Pekka Kekalainen, Erkki Siivola, Roope Lehto, Timo Vesala et al.
Attenuation and delay of active tracers in tube transport is an important current problem, but its full explanation is still lacking. To this end a model is introduced, where part of a tracer undergoes condensation and evaporation, treated as a diffusion-type process, in addition to Taylor dispersio ... [Appl. Phys. Lett. 102, 194101 (2013)] published Mon May 13, 2013.

Effect of the short collection length in silicon microscale wire solar cells

Hyunyub Kim, Joondong Kim, Eunsongyi Lee, Dong-Wook Kim, Ju-Hyung Yun et al.
Electrical and optical properties of silicon microscale wire (SiMW) solar cells were investigated. Diverse designs were applied for SiMW geometries as light absorbers. Finite-difference time-domain simulation shows a focused optical field in the wires inducing an optical absorption enhancement in Si ... [Appl. Phys. Lett. 102, 193904 (2013)] published Mon May 13, 2013.

Highly efficient inverted polymer solar cells with reduced graphene-oxide-zinc-oxide nanocomposites buffer layer

Hyun Woo Lee, Jin Young Oh, Tae Il Lee, Woo Soon Jang, Young Bum Yoo et al.
In this study, we reported a 36% improvement in the performance of inverted solar cells as a result of increased short-circuit current (J) obtained using a composition of zinc oxide (ZnO) and reduced graphene oxide (RGO) as an n-type buffer layer. RGO-ZnO nanocomposites show higher electron conducti ... [Appl. Phys. Lett. 102, 193903 (2013)] published Mon May 13, 2013.

SnS thin film solar cells with ZnMgO buffer layers

Takashi Ikuno, Ryo Suzuki, Kosuke Kitazumi, Naoko Takahashi, Naohiko Kato et al.
The conduction band offset (CBO) of SnS as the light absorbing layer and ZnMgO as the buffer layer in SnS thin film solar cells has been optimized to improve the solar cell conversion efficiency. We controlled the CBO experimentally by varying the Mg content (x) of the ZnMgO layer. The optimum CBO v ... [Appl. Phys. Lett. 102, 193901 (2013)] published Mon May 13, 2013.

Increased open-circuit voltage in a Schottky device using PbS quantum dots with extreme confinement

Hyekyoung Choi, Jun Kwan Kim, Jung Hoon Song, Youngjo Kim, and Sohee Jeong
We fabricated the PbS nanocrystal quantum dots (NQDs) based Schottky structure device (ITO/PbS/LiF/Al) with varying bandgap of NQDs from 0.8 to 2.2 eV. The open-circuit voltage increased monotonically with NQD's bandgap until 0.67 V, achieved using extremely confined, 1.5 nm sized-PbS NQDs. The powe ... [Appl. Phys. Lett. 102, 193902 (2013)] published Mon May 13, 2013.

Enhanced bias stress stability of a-InGaZnO thin film transistors by inserting an ultra-thin interfacial InGaZnO:N layer

Xiaoming Huang, Chenfei Wu, Hai Lu, Fangfang Ren, Dunjun Chen et al.
Amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistors (TFTs) having an ultra-thin nitrogenated a-IGZO (a-IGZO:N) layer sandwiched at the channel/gate dielectric interface are fabricated. It is found that the device shows enhanced bias stress stability with significantly reduced threshol ... [Appl. Phys. Lett. 102, 193505 (2013)] published Mon May 13, 2013.

Dynamic micro-air-bubble drifted in a liquid core fiber Fabry-Perot interferometer for directional fiber-optic level meter

Cheng-Ling Lee, Yang-Chen Zheng, Chia-Lien Ma, Han-Jung Chang, and Chung-Fen Lee
We propose a dynamic, directional, and miniature fiber-optic level meter based on a micro-air-bubble drifted in a liquid-core fiber Fabry-Perot interferometer. The proposed in-fiber level meter can detect the non-horizontal/horizontal state of an object/structure and also be able to discriminate the ... [Appl. Phys. Lett. 102, 193504 (2013)] published Mon May 13, 2013.

Direct observation of nanometer-scale Joule and Peltier effects in phase change memory devices

Kyle L. Grosse, Feng Xiong, Sungduk Hong, William P. King, and Eric Pop
We measure power dissipation in phase change memory (PCM) devices by scanning Joule expansion microscopy (SJEM) with ~50 nm spatial and 0.2 K temperature resolution. The temperature rise in the GeSbTe (GST) is dominated by Joule heating, but at the GST-TiW contacts it is a combination of Peltier and ... [Appl. Phys. Lett. 102, 193503 (2013)] published Mon May 13, 2013.

Electron transport in nano-scaled piezoelectronic devices

Zhengping Jiang, Marcelo A. Kuroda, Yaohua Tan, Dennis M. Newns, Michael Povolotskyi et al.
The Piezoelectronic Transistor (PET) has been proposed as a post-CMOS device for fast, low-power switching. In this device, the piezoresistive channel is metalized via the expansion of a relaxor piezoelectric element to turn the device on. The mixed-valence compound SmSe is a good choice of PET chan ... [Appl. Phys. Lett. 102, 193501 (2013)] published Mon May 13, 2013.

Metamaterial lens made of fully printed resonant-type negative-refractive-index transmission lines

He-Xiu Xu, Guang-Ming Wang, Mei Qing Qi, Yuan-Yuan Lv, and Xi Gao
We studied a well-resolved lens based on planar fully printed resonant-type negative-refractive-index transmission lines made of complementary split ring resonators. The lens goes beyond previous lens in terms of moderate loss and compactness. The focusing has been demonstrated by the circuit theory ... [Appl. Phys. Lett. 102, 193502 (2013)] published Mon May 13, 2013.

Direct graphene synthesis on SiO/Si substrate by ion implantation

R. Zhang, Z. S. Wang, Z. D. Zhang, Z. G. Dai, L. L. Wang et al.
We present results of few-layer graphene synthesis directly on SiO/Si substrate by negative carbon ion implantation in Ni catalyst films on the top of SiO/Si substrate. Negative carbon ions at 20 keV were implanted into Ni films with doses of (416) x 10 cm. The implanted carbon atoms dissolved in ... [Appl. Phys. Lett. 102, 193102 (2013)] published Mon May 13, 2013.

A deeper insight into the operation regime of all-polymeric electrochemical transistors

M. Demelas, E. Scavetta, L. Basirico, R. Rogani, and A. Bonfiglio
All-Organic Electrochemical Transistors (OECTs) realized by employing Poly(3,4-EthyleneDiOxyThiophene) doped with Poly(Styrene Sulfonate) as conductive polymer show a dependence of their behavior on the gate to channel area ratio. This peculiarity has been investigated and the working mechanism has ... [Appl. Phys. Lett. 102, 193301 (2013)] published Mon May 13, 2013.

Tailoring palladium nanocontacts by electromigration

Libe Arzubiaga, Federico Golmar, Roger Llopis, Felix Casanova, and Luis E. Hueso
Electromigration is employed in nanoelectronics for transforming narrow metallic wires into electrodes separated by a few nanometers gap. In this work, we fabricate either nanoconstrictions or nanogap electrodes by performing electromigration in palladium nanowires. The device resistance and the cro ... [Appl. Phys. Lett. 102, 193103 (2013)] published Mon May 13, 2013.

Two-stage processes of electrically induced-ferroelectric to relaxor transition in 0.94(BiNa)TiO-0.06BaTiO

Wook Jo, John Daniels, Dragan Damjanovic, Wolfgang Kleemann, and Jurgen Rodel
The stability of electrically induced long-range ferroelectric order in a relaxor 0.94(BiNa)TiO-0.06BaTiO ceramic material has been investigated by temperature-dependent X-ray diffraction and electrical property measurements. The depolarization and ferroelectric-to-relaxor transition are identified ... [Appl. Phys. Lett. 102, 192903 (2013)] published Mon May 13, 2013.

Thermal conductivity of a ZnO nanowire/silica aerogel nanocomposite

Jing Xie, Anthony Frachioni, D. S. Williams, and B. E. White, Jr.
The thermal conductivity of 100 nm zinc oxide nanowires embedded in silica aerogel was measured using the 3omega method over a temperature range of 150 K to 300 K. Compared to 100 nm ZnO nanowires alone, the thermal conductivity of the nanocomposite was reduced by over an order of magnitude througho ... [Appl. Phys. Lett. 102, 193101 (2013)] published Mon May 13, 2013.

Strain-driven control of piezoelectricity in (Na,Bi)TiO-BaTiO epitaxial thin films

Y. Tanaka, T. Harigai, H. Adachi, N. Sakamoto, N. Wakiya et al.
Thermal strain effect on the piezoelectricity was investigated for (Na,Bi)TiOBaTiO (NBTBT) thin films on various substrates with (100) and (110) orientations. The compressive-thermal strain caused an increase in the remnant polarization unaccompanied by a decrease in dielectric permittivity, which r ... [Appl. Phys. Lett. 102, 192901 (2013)] published Mon May 13, 2013.

Configurational anisotropic spin waves in cross-shaped NiFe nanoelements

B. K. Mahato, B. Rana, R. Mandal, D. Kumar, S. Barman et al.
Optically induced spin waves in NiFe (permalloy) cross-shaped nanoelements are studied by time-resolved magneto-optical Kerr effect microscope. A strong anisotropy in the spin wave modes are observed with the orientation angle (phi) of the in-plane bias magnetic field. As phi deviates from 0 degrees ... [Appl. Phys. Lett. 102, 192402 (2013)] published Mon May 13, 2013.

Spin-phonon coupling in YNiMnO double perovskite probed by Raman spectroscopy

Raimundo Bezerra Macedo Filho, Alejandro Pedro Ayala, and Carlos William de Araujo Paschoal
Temperature-dependent Raman spectroscopy measurements in YNiMnO ceramics were performed in the 20 K850 K range. A detailed analysis of the temperature dependence of the phonon energy of the oxygen octahedra stretching mode shows an anomalous softening below the Curie temperature. This effect was asc ... [Appl. Phys. Lett. 102, 192902 (2013)] published Mon May 13, 2013.

Large coercivity and exchange bias in [Fe(FeO)](TiO) granular films

Y. H. Cheng, X. H. Zhang, L. Y. Li, C. H. Wang, X. G. Luo et al.
[Fe(FeO)](TiO) (0<=delta<=0.91, 0.34<=x<=0.54) granular films were fabricated by magnetron sputtering. Large coercivity (H = 10.5 kOe) and exchange-bias-field (H = 6.5 kOe) at 5 K were found in the film with delta=0.84 and x = 0.48. AC susceptibility measurements exhibit a frequency (f) dependent pe ... [Appl. Phys. Lett. 102, 192403 (2013)] published Mon May 13, 2013.

Magnetic imaging with a Zernike-type phase plate in a transmission electron microscope

Shawn Pollard, Marek Malac, Marco Beleggia, Masahiro Kawasaki, and Yimei Zhu
We demonstrate the use of a hole-free phase plate (HFPP) for magnetic imaging in transmission electron microscopy by mapping the domain structure in PrDyFeB samples. The HFPP, a Zernike-like imaging method, allows for detecting magnetic signals in-focus to correlate the sample crystal structure and ... [Appl. Phys. Lett. 102, 192401 (2013)] published Mon May 13, 2013.

Residual strain and piezoelectric effects in passivated GaAs/AlGaAs core-shell nanowires

Moira Hocevar, Le Thuy Thanh Giang, Rudeesun Songmuang, Martien den Hertog, Lucien Besombes et al.
We observe a systematic red shift of the band-edge of passivated GaAs/AlGaAs core-shell nanowires with increasing shell thickness up to 100 nm. The shift is detected both in emission and absorption experiments, reaching values up to 14 meV for the thickest shell nanowires. Part of this red shift is ... [Appl. Phys. Lett. 102, 191103 (2013)] published Mon May 13, 2013.

Minority current distribution in InGaAs/GaAs transistor-vertical-cavity surface-emitting laser

Y. Xiang, X. Yu, J. Berggren, T. Zabel, M. Hammar et al.
We compare experimental data with three-dimensional numerical calculations of the local minority current in an InGaAs/GaAs transistor vertical-cavity surface-emitting laser at different bias levels. It is demonstrated that lateral potential variations within the device greatly affect the transistor ... [Appl. Phys. Lett. 102, 191101 (2013)] published Mon May 13, 2013.

Faraday rotation in magnetically biased graphene at microwave frequencies

D. L. Sounas, H. S. Skulason, H. V. Nguyen, A. Guermoune, M. Siaj et al.
Faraday rotation is experimentally observed at microwave frequencies in a large-area graphene sheet biased with a static magnetic field, and interrogated by polarized fields in a hollow circular waveguide. A Faraday rotation of up to 1.5 degrees and an isolation of more than 30 dB is observed, sugg ... [Appl. Phys. Lett. 102, 191901 (2013)] published Mon May 13, 2013.

Importance of the localization for inter-subband scattering rates in quasi two-dimensional structures

C. Ndebeka-Bandou, F. Carosella, R. Ferreira, and G. Bastard
The inter-subband scattering in quasi two-dimensional heterostructures is critically examined in the case of cascade structures with a double well design. We show that when two kinds of elastic scatterers are present, the scattering frequencies may markedly differ from the one evaluated for plane wa ... [Appl. Phys. Lett. 102, 191105 (2013)] published Mon May 13, 2013.

Optical time domain reflectometry with low noise waveguide-coupled superconducting nanowire single-photon detectors

C. Schuck, W. H. P. Pernice, X. Ma, and H. X. Tang
We demonstrate optical time domain reflectometry over 200 km of optical fiber using low-noise NbTiN superconducting single-photon detectors integrated with SiN waveguides. Our small detector footprint enables high timing resolution of 50 ps and a dark count rate of 3 Hz with unshielded fibers, allow ... [Appl. Phys. Lett. 102, 191104 (2013)] published Mon May 13, 2013.

Improving information density in ferroelectric polymer films by using nanoimprinted gratings

D. E. Martinez-Tong, M. Soccio, M. C. Garcia-Gutierrez, A. Nogales, D. R. Rueda et al.
In this work, well-defined low aspect ratio nanostructures based on nanogratings on thin films of poly(vinylidene fluoridetrifluoroethylene) copolymers were prepared. By using these nanogratings, an improved management of writing and reading information of about 500 Gbit/in. (0.01 bit/nm) can be rea ... [Appl. Phys. Lett. 102, 191601 (2013)] published Mon May 13, 2013.

Effect of excited states on the ground-state modulation bandwidth in quantum dot lasers

Yuchang Wu, Robert A. Suris, and Levon V. Asryan
We consider direct and indirect (excited-state-mediated) capture of carriers from the waveguide region into the lasing ground state in quantum dots (QDs) and calculate the modulation response of a QD laser. We show that, when only indirect capture is involved, the excited-to-ground-state relaxation ... [Appl. Phys. Lett. 102, 191102 (2013)] published Mon May 13, 2013.

High-performance low-temperature solution-processed InGaZnO thin-film transistors via ultraviolet-ozone photo-annealing

Bo-Yuan Su, Sheng-Yuan Chu, Yung-Der Juang, and Han-Chang Chen
Ultraviolet (UV)-ozone photo-annealing was applied to fabricate low-temperature high-performance solution-processed thin-film transistors (TFTs). With UV-ozone treatment at the optimal temperature of 300 degrees C, TFT devices showed an improved field-effect mobility of 1.73 cm V s, a subthreshold ... [Appl. Phys. Lett. 102, 192101 (2013)] published Mon May 13, 2013.

Long electron spin coherence in ion-implanted GaN: The role of localization

J. H. Buss, J. Rudolph, S. Shvarkov, H. Hardtdegen, A. D. Wieck et al.
The impact of Ga and Au ion implantation on the electron spin dynamics in bulk wurtzite GaN is studied by time-resolved Kerr-rotation spectroscopy. The spin relaxation time increases strongly by up to a factor of 20 for increasing implantation doses. This drastic increase is caused by a transition f ... [Appl. Phys. Lett. 102, 192102 (2013)] published Mon May 13, 2013.

Enhancing the energy of terahertz radiation from plasma produced by intense femtosecond laser pulses

Fazel Jahangiri, Masaki Hashida, Shigeki Tokita, Takeshi Nagashima, Masanori Hangyo et al.
Terahertz (THz) radiation from atomic clusters illuminated by intense femtosecond laser pulses is investigated. By studying the angular distribution, polarization properties and energy dependence of THz waves, we aim to obtain a proper understanding of the mechanism of THz generation. The properties ... [Appl. Phys. Lett. 102, 191106 (2013)] published Mon May 13, 2013.

Influence of excess SrO on the thermoelectric properties of heavily doped SrTiO ceramics

Yifeng Wang, Chunlei Wan, Xiaoyan Zhang, Liming Shen, Kunihito Koumoto et al.
The effects of excess SrO on the thermoelectric properties of n-type SrTiO have been investigated through a comparative study of different polycrystalline ceramic samples. These include Gd-doped SrTiO with varying SrO, nominally in the form of Ruddlesden-Popper phase of SrO(SrTiO) with n = 5, 10, an ... [Appl. Phys. Lett. 102, 183905 (2013)] published Fri May 10, 2013.

Atmospheric-pressure microplasmas with high current density confined inside helium-filled hollow-core fibers

Longfei Ji, Zhenhua Bi, Jinhai Niu, Hongyu Fan, and Dongping Liu
We report on the generation and confinement of atmospheric-pressure microplasmas inside the 100-to-2000-[mu]m-inner-diameter (i.d.) hollow-core fibers (HCFs) filled with helium gas. The microplasma propagation inside these 10-cm-long HCFs results from the anode-driven pulse discharges with their dur ... [Appl. Phys. Lett. 102, 184105 (2013)] published Fri May 10, 2013.

Elastic properties of tetragonal BiFeO from first-principles calculations

Huafeng Dong, Changqing Chen, Shanying Wang, Wenhui Duan, and Jingbo Li
Multiferroic BiFeO can exist in tetragonal G-type and C-type antiferromagnetic phases with a giant c/a ratio and polarizability. In this letter, the elastic constants c's of these tetragonal BiFeO phases are studied as the function of pressure using first-principles density-functional theory. We fin ... [Appl. Phys. Lett. 102, 182905 (2013)] published Fri May 10, 2013.

High thermal stability of optical transparency in cellulose nanofiber paper

Masaya Nogi (能木雅也), Changjae Kim (金&#x 660C;宰), Tohru Sugahara (菅原徹), Tetsuji Inui (乾哲治), Tsukasa Takahashi (高橋&#x 53F8;) et al.
Cellulose nanopapers have been shown to maintain high optical transparency after high temperature heating at 150 degrees C. High temperature heating to around 150 degrees C is inevitable in electronic device processing. If a polyethylene terephthalate film is held at 150 degrees C for tens of min ... [Appl. Phys. Lett. 102, 181911 (2013)] published Fri May 10, 2013.

Electrochemical analysis of transparent oxide-less photovoltaic cell with perforation patterned metal substrate

Myoung Kim, In-Kyu You, Kyoung-Won Lee, In-Hwan Lee, and Ho-Gyeong Yun
In terms of electrochemical behaviour, a transparent conductive oxide (TCO)-less dye-sensitized solar cell (DSSC) with two metal foils was compared with those of a metal foil-based DSSC with a TCO-coated substrate. By virtue of electrochemical impedance spectroscopy, intensity modulated photocurrent ... [Appl. Phys. Lett. 102, 183904 (2013)] published Fri May 10, 2013.

Erratum: Interband tunneling in two-dimensional crystal semiconductors [Appl. Phys. Lett. 102, 132102 (2013)]

Nan Ma and Debdeep Jena
Abstract not available. [Appl. Phys. Lett. 102, 189902 (2013)] published Fri May 10, 2013.

A face-shear mode single crystal ultrasonic motor

Shiyang Li, Wenhua Jiang, Limei Zheng, and Wenwu Cao
We report a face-shear mode ultrasonic motor (USM) made of [011] poled Zt 45 degrees cut 0.24Pb(InNb)O-0.46Pb(MgNb)O-0.30PbTiO single crystal, which takes advantage of the extremely large d = 2368 pC/N. This motor has a maximum no-load linear velocity of 182.5 mm/s and a maximum output force of 1. ... [Appl. Phys. Lett. 102, 183512 (2013)] published Fri May 10, 2013.

Two-electron-satellite transition of donor bound exciton in ZnO: Radiative Auger effect

X. H. Wang and S. J. Xu
Two-electron-satellite (TES) transition of donor bound exciton (DX) is an interesting many-body quantum process. In this letter, precise luminescence spectra and temperature behaviors of the TES transition of aluminum bound exciton in two kinds of zinc oxide single crystals were investigated in deta ... [Appl. Phys. Lett. 102, 181909 (2013)] published Fri May 10, 2013.

Low-resistivity, high-transmittance Ga:ZnO films prepared through metalorganic chemical vapor deposition using an inexpensive solution of diethylzinc in n-hexane as the Zn precursor

Nam Giang Nguyen, Van Thi Thanh Ho, and Lu-Sheng Hong
In this study, we prepared Ga-doped ZnO (GZO) films with qualified opto-electric properties through chemical vapor deposition of an inexpensive solution of diethylzinc in n-hexane (ca. 17 wt. %). The GZO films exhibited low resistivity (3.61 x 10 Omega cm) and high transmittance (85%) in the visib ... [Appl. Phys. Lett. 102, 181912 (2013)] published Fri May 10, 2013.

Low-temperature epitaxial growth of high quality SiGe (x >= 0.99) films on Si(001) wafer by reactive thermal chemical vapor deposition

Ke Tao, Yoshinori Kurosawa, and Jun-ichi Hanna
Epitaxial growth of silicon-germanium (SiGe: 0 <= x <= 1) thin films on Si(001) substrate at low temperature has been investigated using reactive thermal CVD. SiH and GeF are used as source gases. The results indicate that SiGe (x >= 0.99) epilayer can be prepared directly on Si wafer at 350 degree ... [Appl. Phys. Lett. 102, 182109 (2013)] published Fri May 10, 2013.

Investigation of size and electronic effects on Kapitza conductance with non-equilibrium molecular dynamics

R. E. Jones, J. C. Duda, X. W. Zhou, C. J. Kimmer, and P. E. Hopkins
In nanosystems, the thermal resistance between materials typically dominates the overall resistance. While size effects on thermal conductivity are well documented, size effects on thermal boundary conductance have only been speculated. In response, we characterize the relationship between interfaci ... [Appl. Phys. Lett. 102, 183119 (2013)] published Fri May 10, 2013.

Temperature dependence of the average electron-hole pair creation energy in AlGaAs

A. M. Barnett, J. E. Lees, and D. J. Bassford
The temperature dependence of the average energy consumed in the creation of an electron-hole pair in the wide bandgap compound semiconductor AlGaAs is reported following X-ray measurements made using an AlGaAs photodiode diode coupled to a low-noise charge-sensitive preamplifier operating in spectr ... [Appl. Phys. Lett. 102, 181119 (2013)] published Fri May 10, 2013.

Polarity control and growth of lateral polarity structures in AlN

Ronny Kirste, Seiji Mita, Lindsay Hussey, Marc P. Hoffmann, Wei Guo et al.
The control of the polarity of metalorganic chemical vapor deposition grown AlN on sapphire is demonstrated. Al-polar and N-polar AlN is grown side-by-side yielding a lateral polarity structure. Scanning electron microscopy measurements reveal a smooth surface for the Al-polar and a relatively rough ... [Appl. Phys. Lett. 102, 181913 (2013)] published Fri May 10, 2013.

Intersubband plasmon-phonon coupling in GaAsP/AlGaAs near surface quantum well

R. Aggarwal, Alka A. Ingale, Suparna Pal, V. K. Dixit, T. K. Sharma et al.
The investigation of electron-phonon coupling in near surface GaAsP/AlGaAs quantum well structures using wavelength and intensity dependent Raman spectroscopy shows that in the near surface quantum well case, coupled modes are situated at the frequency between longitudinal optical (LO) and transvers ... [Appl. Phys. Lett. 102, 181120 (2013)] published Fri May 10, 2013.

Quantification of trap state densities in GaAs heterostructures grown at varying rates using intensity-dependent time resolved photoluminescence

C. R. Haughn, K. J. Schmieder, J. M. O. Zide, A. Barnett, C. Ebert et al.
Time-resolved photoluminescence is an established technique for characterizing carrier lifetimes in semiconductors, but the dependence of lifetime on excitation fluence has been only qualitatively investigated. We develop a quantitative approach for fitting fluence-dependent PL decay data to a Shock ... [Appl. Phys. Lett. 102, 182108 (2013)] published Fri May 10, 2013.

Influence of crystalline titanium oxide layer smoothness on the performance of inverted organic bilayer solar cells

Etienne Berner, Timo Jager, Thomas Lanz, Frank Nuesch, Jean-Nicolas Tisserant et al.
Due to the small exciton diffusion length in organic materials, the donor-acceptor heterointerface in simple bilayer solar cells must be placed in close proximity to the bottom electrode. This makes great demands on the planarity of the base layer, since a non-uniform topography can cause adverse sh ... [Appl. Phys. Lett. 102, 183903 (2013)] published Fri May 10, 2013.

AgInSbTe memristor with gradual resistance tuning

J. J. Zhang, H. J. Sun, Y. Li, Q. Wang, X. H. Xu et al.
A chalcogenide material with Ag/AgInSbTe/Ag structure was proposed as a memristor. Reproducible gradual resistance tuning in bipolar/unipolar modes was demonstrated. The resistance variation was tuned more precisely by controlling the polarity, the amplitude, the width, and the number of applied vol ... [Appl. Phys. Lett. 102, 183513 (2013)] published Fri May 10, 2013.

Controlled softening of CuZr metallic glass by ion irradiation

K. A. Avchaciov, Y. Ritter, F. Djurabekova, K. Nordlund, and K. Albe
We study the effect of irradiation with 520 keV recoils on the topological and chemical short-range order of CuZr metallic glass using molecular dynamics simulations. We show that within the cascade region, the structural backbone of stiff Cu-centered icosahedral units is destroyed, leading to local ... [Appl. Phys. Lett. 102, 181910 (2013)] published Fri May 10, 2013.

Oxygen vacancy enhanced room temperature magnetism in Al-doped MgO nanoparticles

Debabrata Mishra, Balaji P. Mandal, Rupam Mukherjee, Ratna Naik, Gavin Lawes et al.
We have measured the room temperature magnetization in Al-substituted magnesium oxide, Mg(Al)O nanoparticles with Al fractions of up to 5 at. %. All samples, including undoped MgO nanoparticles, exhibit weak room temperature ferromagnetism, with the saturation magnetization reaching a maximum of 0.0 ... [Appl. Phys. Lett. 102, 182404 (2013)] published Fri May 10, 2013.

III-nitride light-emitting diode with embedded photonic crystals

K. H. Li, K. Y. Zang, S. J. Chua, and H. W. Choi
A photonic crystal has been embedded within an InGaN/GaN light-emitting diode structure via epitaxial lateral overgrowth of a p-type GaN capping layer. The photonic crystal is a hexagonal-closed-packed array of nano-pillars patterned by nanosphere lithography; the capping layer planarizes the discon ... [Appl. Phys. Lett. 102, 181117 (2013)] published Fri May 10, 2013.

Influence of the transparent conductive oxide layer deposition step on electrical properties of silicon heterojunction solar cells

W. Favre, J. Coignus, N. Nguyen, R. Lachaume, R. Cabal et al.
This work deals with the understanding of the transport behavior of different deposited Indium Tin Oxide (ITO) layers on the emitter of n-type heterojunction solar cells. A complete study based on effective lifetime measurements has been carried out on samples with different ITO thicknesses to evalu ... [Appl. Phys. Lett. 102, 181118 (2013)] published Fri May 10, 2013.

Ag dendritic nanostructures as ultrastable substrates for surface-enhanced Raman scattering

Yu Fei Chan, Chang Xing Zhang, Zheng Long Wu, Dan Mei Zhao, Wei Wang et al.
Dendritic silver nanostructures coated with silica nanofilm are synthesized via hydrothermal etching using silver nitrate, hydrofluoric acid, and hydrogen peroxide and controlling the reagent concentration, reaction time, and temperature. The silver dendritic nanostructures are employed as substrate ... [Appl. Phys. Lett. 102, 183118 (2013)] published Fri May 10, 2013.