APL: Device Physics http://scitation.aip.org/ APL: Device Physics Efficient inverted top-emitting organic light-emitting diodes using ultrathin MoO/C bilayer structure to enhance hole injection http://link.aip.org/link/?APL/95/203508/1&agg=rss Jianhua Hou, Jiang Wu, Zhiyuan Xie, and Lixiang Wang<br/> Efficient inverted top-emitting organic light-emitting diodes with aluminum (Al) as both the cathode and semitransparent anode are investigated. It is found that introduction of the ultrathin molybdenum trioxide (MoO)/fullerene (C) bilayer structure between the low work function Al top anode and the ... [Appl. Phys. Lett. 95, 203508 (2009)] published Fri Nov 20, 2009. Telescopic hot double wall carbon nanotube for nanolithography http://link.aip.org/link/?APL/95/203507/1&agg=rss A. Popescu and L. M. Woods<br/> A custom double wall carbon nanotube for thermal surface modification is proposed. By studying the heat transfer characteristics in the system, it is demonstrated that such a device is capable of producing high resolution patterns on a sample surface. A constant distance between the double wall carb ... [Appl. Phys. Lett. 95, 203507 (2009)] published Thu Nov 19, 2009. Bipolar resistive switching in individual AuNiOAu segmented nanowires http://link.aip.org/link/?APL/95/203505/1&agg=rss Edward D. Herderick, Kongara M. Reddy, Rachel N. Sample, Thomas I. Draskovic, and Nitin P. Padture<br/> Evidence for bipolar resistive switching is reported in individual metal-oxide-metal (MOM) nanowires in the system AuNiOAu, and a plausible mechanism for the same is presented. The MOM nanowire architecture may be well suited for much needed fundamental studies of resistive switching because it prov ... [Appl. Phys. Lett. 95, 203505 (2009)] published Tue Nov 17, 2009. The effects of processing of high-electron-mobility transistors on the strain state and the electrical properties of AlGaN/GaN structures http://link.aip.org/link/?APL/95/203504/1&agg=rss F. Gonzalez-Posada Flores, C. Rivera, and E. Munoz<br/> The results of x-ray characterization presented in this work show that the strain state of the AlGaN and GaN layers is modified by the Ohmic contact deposition and subsequent annealing, as well as by the SiN passivation. In both cases, the tensile strain for the AlGaN layer decreases whereas the res ... [Appl. Phys. Lett. 95, 203504 (2009)] published Mon Nov 16, 2009. Enhanced nonvolatile resistive switching in dilutely cobalt doped TiO http://link.aip.org/link/?APL/95/203502/1&agg=rss Kashinath A. Bogle, Mukesh N. Bachhav, Meenal S. Deo, Nagarajan Valanoor, and Satishchandra B. Ogale<br/> Incorporation of dilute concentration of dopant having a valence state different than that of the host cation enables controlled incorporation proximity vacancy defects for local charge balance. Since nonvolatile resistive switching is a phenomenon tied to such defects, it can be expected to be infl ... [Appl. Phys. Lett. 95, 203502 (2009)] published Mon Nov 16, 2009. Periodic response of fluidic networks with passive deformable features http://link.aip.org/link/?APL/95/203501/1&agg=rss Matthew R. Begley, Marcel Utz, Daniel C. Leslie, Hossein Haj-Hariri, James Landers et al.<br/> This paper outlines the scaling parameters governing the frequency response of fluidic networks with embedded deformable features, which are subjected to periodic excitation. These parameters describe the impact of deformable feature properties on the relative importance of potential energy, kinetic ... [Appl. Phys. Lett. 95, 203501 (2009)] published Mon Nov 16, 2009. Origins of performance in fiber-based organic photovoltaics http://link.aip.org/link/?APL/95/203503/1&agg=rss Yuan Li, Wei Zhou, Dan Xue, Jiwen Liu, Eric D. Peterson et al.<br/> Using ray tracing and optical path iteration, we present a mathematical model for light transmission, absorption, and loss in fiber-based organic photovoltaics. Simulations based on this model give an optimum incident angle, position, and an optimum aspect ratio in terms of other parameters of the f ... [Appl. Phys. Lett. 95, 203503 (2009)] published Mon Nov 16, 2009. High-directivity antenna with small antenna aperture http://link.aip.org/link/?APL/95/193506/1&agg=rss Yu Luo, Jingjing Zhang, Hongsheng Chen, Jiangtao Huangfu, and Lixin Ran<br/> We show in this letter that, by using an inhomogeneous metamaterial shell, it is possible to achieve highly directive emission with a small antenna aperture. The material parameters of the metamaterial substrate are obtained by a nonmonotonic optical transformation. Therefore, a large antenna can be ... [Appl. Phys. Lett. 95, 193506 (2009)] published Fri Nov 13, 2009. Terahertz detector based on a superconducting tunnel junction coupled to a thin superconductor film http://link.aip.org/link/?APL/95/193504/1&agg=rss Seiichiro Ariyoshi, Tohru Taino, Adrian Dobroiu, Hiromi Sato, Hiroshi Matsuo et al.<br/> The principle of a terahertz detector using a superconducting tunnel junction (STJ) coupled to a large terahertz-absorbing superconductor film is verified. We have detected terahertz radiation based on the Cooper-pair breaking process, and confirmed that the sensitivity has a sharp increase around 0 ... [Appl. Phys. Lett. 95, 193504 (2009)] published Fri Nov 13, 2009. Effect of surface stress on the stiffness of cantilever plates: Influence of cantilever geometry http://link.aip.org/link/?APL/95/193505/1&agg=rss Michael J. Lachut and John E. Sader<br/> Numerous measurements have indicated that surface stress can significantly modify the stiffness of cantilever sensors. In contrast, theoretical calculations using classical beam theory predict that stiffness is independent of surface stress. Using a three-dimensional analysis, we recently showed tha ... [Appl. Phys. Lett. 95, 193505 (2009)] published Fri Nov 13, 2009. Effects of Li doping on the performance and environmental stability of solution processed ZnO thin film transistors http://link.aip.org/link/?APL/95/193503/1&agg=rss Pradipta K. Nayak, Jongsu Jang, Changhee Lee, and Yongtaek Hong<br/> We report the effects of lithium (Li) doping on the performance and environmental stability of solution processed zinc oxide (ZnO) thin film transistors (TFTs). It was found that appropriate amount of Li doping significantly reduced the background conductivity of ZnO films and also improved the orie ... [Appl. Phys. Lett. 95, 193503 (2009)] published Wed Nov 11, 2009. High contrast chiral nematic liquid crystal device using negative dielectric material http://link.aip.org/link/?APL/95/193502/1&agg=rss Su Seok Choi, Flynn Castles, Stephen M. Morris, and Harry J. Coles<br/> A liquid crystal device is demonstrated using a short-pitch (260 nm) chiral nematic with negative dielectric anisotropy. Due to dielectric coupling, an in-plane electric field switches the liquid crystal between the standing-helix (field-off, dark state) and lying-helix (field-on, transmissive state ... [Appl. Phys. Lett. 95, 193502 (2009)] published Tue Nov 10, 2009. Light emitting field effect transistor with two self-aligned Si nanocrystal layers http://link.aip.org/link/?APL/95/193501/1&agg=rss V. Beyer, B. Schmidt, K.-H. Heinig, and K.-H. Stegemann<br/> Light emitting field effect transistors based on narrow layers of silicon nanocrystals (NCs) in the gate oxide were fabricated. Direct quantum mechanical electron and hole tunneling into NCs was achieved by self-alignment of NCs-interface-distances to ~2 nm. The direct tunneling reduces oxide degra ... [Appl. Phys. Lett. 95, 193501 (2009)] published Mon Nov 9, 2009. Highly efficient cross-linked PbS nanocrystal/C hybrid heterojunction photovoltaic cells http://link.aip.org/link/?APL/95/183505/1&agg=rss S. W. Tsang, H. Fu, R. Wang, J. Lu, K. Yu et al.<br/> We present a highly efficient hybrid heterojunction photovoltaic (PV) cell with a colloidal inorganic nanocrystal (NC) electron donor and an organic electron acceptor. The heterojunction is formed by a thin film of cross-linked PbS NCs and a vacuum deposited C layer. Compared to the PbS-only PV cell ... [Appl. Phys. Lett. 95, 183505 (2009)] published Thu Nov 5, 2009. Energy band-alignment of a multimetal-layer gated metal-oxide-semiconductor structure http://link.aip.org/link/?APL/95/183506/1&agg=rss Zilan Li, Michel Houssa, Tom Schram, Stefan De Gendt, and Kristin De Meryer<br/> The energy band-alignment of a multimetal-layer gated metal-oxide-semiconductor structure is investigated. An analytical expression for the Fermi level of the metal stack is derived. It is shown that the thin metal layer contacting the gate dielectric plays a critical role in determining the work fu ... [Appl. Phys. Lett. 95, 183506 (2009)] published Thu Nov 5, 2009. Self-assembled nanodielectrics and silicon nanomembranes for low voltage, flexible transistors, and logic gates on plastic substrates http://link.aip.org/link/?APL/95/183504/1&agg=rss Hoon-Sik Kim, Sang Min Won, Young-Geun Ha, Jong-Hyun Ahn, Antonio Facchetti et al.<br/> This letter reports the fabrication and electrical characterization of mechanically flexible and low operating voltage transistors and logic gates (NOT, NAND, and NOR gates) using printed silicon nanomembranes and self-assembled nanodielectrics on thin plastic substrates. The transistors exhibit eff ... [Appl. Phys. Lett. 95, 183504 (2009)] published Wed Nov 4, 2009. Improved red-response in thin film a-Si:H solar cells with soft-imprinted plasmonic back reflectors http://link.aip.org/link/?APL/95/183503/1&agg=rss Vivian E. Ferry, Marc A. Verschuuren, Hongbo B. T. Li, Ruud E. I. Schropp, Harry A. Atwater et al.<br/> The impact of controlled nanopatterning on the Ag back contact of an n-i-p a-Si:H solar cell was investigated experimentally and through electromagnetic simulation. Compared to a similar reference cell with a flat back contact, we demonstrate an efficiency increase from 4.5% to 6.2%, with a 26% incr ... [Appl. Phys. Lett. 95, 183503 (2009)] published Tue Nov 3, 2009. Minority electron unipolar photodetectors based on type II InAs/GaSb/AlSb superlattices for very long wavelength infrared detection http://link.aip.org/link/?APL/95/183502/1&agg=rss B.-M. Nguyen, S. Bogdanov, S. Abdollahi Pour, and M. Razeghi<br/> We present a hybrid photodetector design that inherits the advantages of traditional photoconductive and photovoltaic devices. The structure consists of a barrier layer blocking the transport of majority holes in a p-type semiconductor, resulting in an electrical transport due to minority carriers w ... [Appl. Phys. Lett. 95, 183502 (2009)] published Tue Nov 3, 2009. Trigonal paramagnetic interface defect in epitaxial GeN/(111)Ge http://link.aip.org/link/?APL/95/183501/1&agg=rss A. P. D. Nguyen, A. Stesmans, V. V. Afanas'ev, R. R. Lieten, and G. Borgs<br/> We report on the observation by electron spin resonance (ESR) of an anisotropic paramagnetic defect at the interface of epitaxially grown GeN/(111)Ge entities with nanometer thin GeN layers. The defect exhibits trigonal C symmetry characterized by g[approximate]2.0023 and g[approximate]2.0032, and i ... [Appl. Phys. Lett. 95, 183501 (2009)] published Tue Nov 3, 2009. Leakage current and reverse-bias luminescence in InGaN-based light-emitting diodes http://link.aip.org/link/?APL/95/173507/1&agg=rss M. Meneghini, N. Trivellin, M. Pavesi, M. Manfredi, U. Zehnder et al.<br/> This paper reports an electro-optical analysis of the correlation between reverse-bias leakage current and luminescence in light-emitting diodes based on InGaN. The results of the analysis suggest that (i) the main mechanism responsible for leakage current conduction is tunneling, (ii) leakage curre ... [Appl. Phys. Lett. 95, 173507 (2009)] published Thu Oct 29, 2009. Impact of Sn/Zn ratio on the gate bias and temperature-induced instability of Zn-In-Sn-O thin film transistors http://link.aip.org/link/?APL/95/173508/1&agg=rss Min Ki Ryu, Shinhyuk Yang, Sang-Hee Ko Park, Chi-Sun Hwang, and Jae Kyeong Jeong<br/> We investigated the effect of the Sn/Zn ratio in the amorphous Zn-In-Sn-O (ZITO) system on the gate voltage stress-induced stability of the resulting thin film transistors (TFTs). The device stability of the TFTs with a composition channel of Zn:In:Sn=0.35:0.20:0.45 (device C) was dramatically impro ... [Appl. Phys. Lett. 95, 173508 (2009)] published Thu Oct 29, 2009.