Organic Electronics and Photonics http://scitation.aip.org/ Organic Electronics and Photonics Efficient bilayer phosphorescent organic light-emitting diodes: Direct hole injection into triplet dopants http://link.aip.org/link/?OEP/2/87/1&agg=rss Z. W. Liu, M. G. Helander, Z. B. Wang, and Z. H. Lu<br/> In phosphorescent organic light-emitting diodes (OLEDs), a hole transporting layer is traditionally thought to be required to facilitate hole injection into the host molecule. It is found that fac-tris(2-phenylpyridine)iridium [Ir(ppy)] doped into 4,4-N,N-dicarbazole-biphenyl can be used to directly ... [Appl. Phys. Lett. 94, 113305 (2009)] published Thu Mar 19, 2009. Interface dipole at metal-organic interfaces: Contribution of metal induced interface states http://link.aip.org/link/?OEP/2/86/1&agg=rss C. S. Lee, J. X. Tang, Y. C. Zhou, and S. T. Lee<br/> Despite the importance of interface dipole on the charge carrier injection at metal/organic contacts, there is yet no estimation of the various contributions to the overall dipole. We propose a simple approach to delineate and estimate the contribution of metal-induced interface states (MISs) toward ... [Appl. Phys. Lett. 94, 113304 (2009)] published Thu Mar 19, 2009. Low-voltage organic transistors with titanium oxide/polystyrene bilayer dielectrics http://link.aip.org/link/?OEP/2/85/1&agg=rss Yingxi Lu, Wi Hyoung Lee, Hwa Sung Lee, Yunseok Jang, and Kilwon Cho<br/> Pentacene-based low-voltage organic transistors were realized with titanium oxide/polystyrene (TiO/PS) bilayer dielectrics. Significantly, the TiO bottom layer was fabricated by a layer-by-layer deposition procedure and had an ultrathin thickness (<5 nm). The nonpolar PS top layer not only shields ... [Appl. Phys. Lett. 94, 113303 (2009)] published Thu Mar 19, 2009. Transient photovoltaic behavior of air-stable, inverted organic solar cells with solution-processed electron transport layer http://link.aip.org/link/?OEP/2/84/1&agg=rss Chang Su Kim, Stephanie S. Lee, Enrique D. Gomez, Jong Bok Kim, and Yueh-Lin Loo<br/> The short-circuit current density of inverted organic solar cells comprising a solution-processed titania electron transport layer increases with continuous illumination in air and saturates after 10 min. On extended exposure (>2 days), the open-circuit voltage of the devices increases also. The im ... [Appl. Phys. Lett. 94, 113302 (2009)] published Tue Mar 17, 2009. Light-induced charge transfer in hybrid composites of organic semiconductors and silicon nanocrystals http://link.aip.org/link/?OEP/2/83/1&agg=rss Roland Dietmueller, Andre R. Stegner, Robert Lechner, Sabrina Niesar, Rui N. Pereira et al.<br/> Charge transfer between silicon nanocrystals (Si-nc) and organic semiconductors has been investigated via light-induced electron spin resonance (LESR). Composites of Si-nc with the hole conductor poly(3-hexylthiophene) (P3HT) and with the electron acceptor [6,6]-phenyl-C-butyric acid methyl ester (P ... [Appl. Phys. Lett. 94, 113301 (2009)] published Tue Mar 17, 2009. Direct observation of the charge carrier concentration in organic field-effect transistors by electron spin resonance http://link.aip.org/link/?OEP/2/82/1&agg=rss Hisaaki Tanaka, Shun-ichiro Watanabe, Hiroshi Ito, Kazuhiro Marumoto, and Shin-ichi Kuroda<br/> Charge carrier concentration in operating field-effect transistor (FET) of regioregular poly(3-hexylthiophene) has been directly determined by electron spin resonance (ESR). ESR signals of field-induced polarons are observed around g=2.003 under the application of negative gate-source voltage (V). U ... [Appl. Phys. Lett. 94, 103308 (2009)] published Fri Mar 13, 2009. Three-dimensional organic field-effect transistors with high output current and high on-off ratio http://link.aip.org/link/?OEP/2/81/1&agg=rss Mayumi Uno, I. Doi, K. Takimiya, and J. Takeya<br/> High-performance three-dimensional organic field-effect transistors are developed with multiple vertical channels of organic semiconductors. Advanced processes of vacuum depositing high-mobility and air-stable dinaphtho[2,3-b:2,3-f]thieno[3,2-b]thiophene thin films on a series of horizontally elonga ... [Appl. Phys. Lett. 94, 103307 (2009)] published Fri Mar 13, 2009. Enhancement in open circuit voltage induced by deep interface hole traps in polymer-fullerene bulk heterojunction solar cells http://link.aip.org/link/?OEP/2/79/1&agg=rss Chunfu Zhang, S. W. Tong, Chunxiang Zhu, Changyun Jiang, E. T. Kang et al.<br/> A significant increase in open circuit voltage (V) is obtained in the polymer-fullerene bulk heterojunction solar cell by using the e-beam deposited Al cathode. Compared with the device with the thermal evaporated Al cathode, an obvious enhancement of V from 596 to 664 mV is obtained, which makes th ... [Appl. Phys. Lett. 94, 103305 (2009)] published Thu Mar 12, 2009. Response to Comment on `Gain coefficient method for amplified spontaneous emission in thin waveguided film of a conjugated polymer' [Appl. Phys. Lett. 94, 106101 (2009)] http://link.aip.org/link/?OEP/2/78/1&agg=rss I. Silvestre, P. W. B. Marques, M. Valadares, and L. A. Cury<br/> Abstract not available. [Appl. Phys. Lett. 94, 106102 (2009)] published Thu Mar 12, 2009. Laser direct write printing of sensitive and robust light emitting organic molecules http://link.aip.org/link/?OEP/2/80/1&agg=rss Nicholas T. Kattamis, Neal D. McDaniel, Stefan Bernhard, and Craig B. Arnold<br/> We examine the effects of three laser direct-write (LDW) printing techniques on 9-anthracenemethanol and tris(8-hydroxyquinoline)aluminum (Alq) organic luminophores in order to link the differences in transfer mechanism to the resulting material properties. Degradation can occur where laser light an ... [Appl. Phys. Lett. 94, 103306 (2009)] published Thu Mar 12, 2009. Comment on Gain coefficient method for amplified spontaneous emission in thin waveguided film of a conjugated polymer [Appl. Phys. Lett. 93, 163307 (2008)] http://link.aip.org/link/?OEP/2/77/1&agg=rss Sebastien Chenais and Sebastien Forget<br/> Abstract not available. [Appl. Phys. Lett. 94, 106101 (2009)] published Thu Mar 12, 2009. Effect of metal cathode reflectance on the exciton-dissociation efficiency in heterojunction organic solar cells http://link.aip.org/link/?OEP/2/76/1&agg=rss Ajay K. Pandey, Paul E. Shaw, Ifor D. W. Samuel, and Jean-Michel Nunzi<br/> Effects of different cathode metals, such as aluminum, calcium, and silver, and difference in their reflectivity on the photocurrent generation in pentacene-C heterojunction solar cell are presented. Using optical transfer matrix calculations, we find that metal reflectivity has a profound impact on ... [Appl. Phys. Lett. 94, 103303 (2009)] published Wed Mar 11, 2009. Directional photoluminescence enhancement of organic emitters via surface plasmon coupling http://link.aip.org/link/?OEP/2/75/1&agg=rss Shou-Yu Nien, Nan-Fu Chiu, Yu-Hsuan Ho, Jiun-Haw Lee, Chii-Wann Lin et al.<br/> In this paper, we had quantitatively investigated the photoluminescence of organic emitter on a Si substrate with periodically corrugated metal thin film experimentally and theoretically. Due to the plasmonic coupling by the metal gratings, 4.3 times and 1.7 times enhancements in optical intensities ... [Appl. Phys. Lett. 94, 103304 (2009)] published Wed Mar 11, 2009. Microcavity top-emitting organic light-emitting devices integrated with diffusers for simultaneous enhancement of efficiencies and viewing characteristics http://link.aip.org/link/?OEP/2/74/1&agg=rss Chih-Che Liu, Su-Hao Liu, Kun-Cheng Tien, Min-Hung Hsu, Hong-Wei Chang et al.<br/> We show that integrating diffuser films with microcavity top-emitting organic light-emitting devices (OLEDs) provide a convenient approach for simultaneously achieving large quantum- efficiency enhancement (1.38 times compared to top-emitting devices without diffusers and 2.1 times compared to conve ... [Appl. Phys. Lett. 94, 103302 (2009)] published Wed Mar 11, 2009. A low band gap, solution processable oligothiophene with a dialkylated diketopyrrolopyrrole chromophore for use in bulk heterojunction solar cells http://link.aip.org/link/?OEP/2/73/1&agg=rss Arnold Bernarte Tamayo, Xuan-Dang Dang, Bright Walker, Junghwa Seo, Tyler Kent et al.<br/> Bulk heterojunction solar cells are fabricated from blends of oligothiophene with a dialkylated diketopyrrolopyrrole chromophore:[6,6]-phenyl C butyric acid methyl ester. Absorption and photocurrent of the films extend to 800 nm. A power conversion efficiency (PCE) of 3.0% is obtained under simulate ... [Appl. Phys. Lett. 94, 103301 (2009)] published Mon Mar 9, 2009. Position sensitive, continuous wavelength tunable laser based on photopolymerizable cholesteric liquid crystals with an in-plane helix alignment http://link.aip.org/link/?OEP/2/72/1&agg=rss Hiroyuki Yoshida, Yo Inoue, Takuya Isomura, Yuko Matsuhisa, Akihiko Fujii et al.<br/> Position sensitive lasing with continuous wavelength tunability and emission in the cell-plane direction is demonstrated from a photopolymerized cholesteric liquid crystal film. The device has a gradually dilating helix lying in the cell-plane direction and is fabricated by applying a vertical elect ... [Appl. Phys. Lett. 94, 093306 (2009)] published Fri Mar 6, 2009. Surface selective deposition of molecular semiconductors for solution-based integration of organic field-effect transistors http://link.aip.org/link/?OEP/2/71/1&agg=rss Takeo Minari<!--orlang--> (&#x4E09;&#x6210;&#x525B;&#x751F;)<!--orlang-->, Masataka Kano<!--orlang--> (&#x52A0;&#x7D0D;&#x6B63;&#x9686;)<!--orlang-->, Tetsuhiko Miyadera<!--orlang--> (&#x5BAE;&#x5BFA;&#x54F2;&#x5F66;)<!--orlang-->, Sui-Dong Wang<!--orlang--> (&#x738B;&#x7A42;&#x6771;)<!--orlang-->, Yoshinobu Aoyagi<!--orlang--> (&#x9752;&#x67F3;&#x514B;&#x4FE1;)<!--orlang--> et al.<br/> A bottom-up fabrication technique for the preparation of self-organized organic field-effect transistors (OFETs) on flexible plastic substrates is presented. Solution-based self-organization of OFETs is achieved by patterning the insulator surface with solution-wettable and unwettable regions. The p ... [Appl. Phys. Lett. 94, 093307 (2009)] published Fri Mar 6, 2009. Control of threshold voltage and hysteresis in organic field-effect transistors http://link.aip.org/link/?OEP/2/70/1&agg=rss Hideyuki Kawaguchi, Masateru Taniguchi, and Tomoji Kawai<br/> We have fabricated organic field-effect transistors that have hybrid gate insulating films, consisting of an inorganic insulating film and a cross-linked insulating polymer. The hybrid insulating films allow the capacitance to be controlled easily, which makes it possible to reduce the influence of ... [Appl. Phys. Lett. 94, 093305 (2009)] published Thu Mar 5, 2009. Transparent conductive oxide layer-less dye-sensitized solar cells consisting of floating electrode with gradient TiO blocking layer http://link.aip.org/link/?OEP/2/68/1&agg=rss Yoshikazu Yoshida, Shyam S. Pandey, Kenshiro Uzaki, Shuzi Hayase, Mitsuru Kono et al.<br/> A transparent conductive oxide less dye-sensitized solar cell (TCO-less DSC) consisting of a glass/a floating electrode (FE)/a stained nanoporous titania layer/a gel electrolyte sheet/a Pt layer/a Ti sheet is reported. The FE is composed of a stainless mesh sheet covered with a gradient TiO layer, w ... [Appl. Phys. Lett. 94, 093301 (2009)] published Wed Mar 4, 2009. Controlling of the surface energy of the gate dielectric in organic field-effect transistors by polymer blend http://link.aip.org/link/?OEP/2/67/1&agg=rss Jia Gao, Kamal Asadi, Jian Bin Xu, and Jin An<br/> In this letter, we demonstrate that by blending insulating polymers, one can fabricate an insulating layer with controllable surface energy for organic field-effect transistors. As a model system, we used copper phthalocyanine evaporated on layers of polymethyl metacrylate blended with polystyrene w ... [Appl. Phys. Lett. 94, 093302 (2009)] published Wed Mar 4, 2009. Flexible low voltage nonvolatile memory transistors with pentacene channel and ferroelectric polymer http://link.aip.org/link/?OEP/2/69/1&agg=rss Kwang H. Lee, Gyubaek Lee, Kimoon Lee, Min Suk Oh, and Seongil Im<br/> We report on the fabrication of pentacene-based nonvolatile memory thin-film transistors (NVM-TFTs) with thin poly(vinylidene fluoride/trifluoroethylene) ferroelectric gate insulators. Our NVM-TFT adopts flexible polyethersulfone substrate and operates under the low voltage write-erase (WR-ER) pulse ... [Appl. Phys. Lett. 94, 093304 (2009)] published Wed Mar 4, 2009.