Organic semiconductor

About: Organic semiconductor is a research topic. Over the lifetime, 15905 publications have been published within this topic receiving 533881 citations.

Carbon Nitride-Aromatic Diimide-Graphene Nanohybrids: Metal-Free Photocatalysts for Solar-to-Hydrogen Peroxide Energy Conversion with 0.2% Efficiency.

Abstract: Solar-to-chemical energy conversion is a challenging subject for renewable energy storage. In the past 40 years, overall water splitting into H2 and O2 by semiconductor photocatalysis has been studied extensively; however, they need noble metals and extreme care to avoid explosion of the mixed gases. Here we report that generating hydrogen peroxide (H2O2) from water and O2 by organic semiconductor photocatalysts could provide a new basis for clean energy storage without metal and explosion risk. We found that carbon nitride–aromatic diimide–graphene nanohybrids prepared by simple hydrothermal–calcination procedure produce H2O2 from pure water and O2 under visible light (λ > 420 nm). Photoexcitation of the semiconducting carbon nitride–aromatic diimide moiety transfers their conduction band electrons to graphene and enhances charge separation. The valence band holes on the semiconducting moiety oxidize water, while the electrons on the graphene moiety promote selective two-electron reduction of O2. This me...

Controlling Molecular Doping in Organic Semiconductors

Abstract: The field of organic electronics thrives on the hope of enabling low-cost, solution-processed electronic devices with mechanical, optoelectronic, and chemical properties not available from inorganic semiconductors. A key to the success of these aspirations is the ability to controllably dope organic semiconductors with high spatial resolution. Here, recent progress in molecular doping of organic semiconductors is summarized, with an emphasis on solution-processed p-type doped polymeric semiconductors. Highlighted topics include how solution-processing techniques can control the distribution, diffusion, and density of dopants within the organic semiconductor, and, in turn, affect the electronic properties of the material. Research in these areas has recently intensified, thanks to advances in chemical synthesis, improved understanding of charged states in organic materials, and a focus on relating fabrication techniques to morphology. Significant disorder in these systems, along with complex interactions between doping and film morphology, is often responsible for charge trapping and low doping efficiency. However, the strong coupling between doping, solubility, and morphology can be harnessed to control crystallinity, create doping gradients, and pattern polymers. These breakthroughs suggest a role for molecular doping not only in device function but also in fabrication-applications beyond those directly analogous to inorganic doping.

Double and triple junction polymer solar cells processed from solution

Abstract: Multiple junction solar cells incorporating polymer:fullerene bulk heterojunctions as active layers and solution processed electron and hole transport layers are presented. The recombination layer, deposited between the active layers, is fabricated by spin coating ZnO nanoparticles from acetone, followed by spin coating neutral pH poly(3,4-ethylenedioxythiophene) from water and short UV illumination of the completed device. The key advantage of this procedure is that each step does not affect the integrity of previously deposited layers. The open-circuit voltage (Voc) for double and triple junction solar cells is close to the sum of the Voc’s of individual cells.

"Organic Light-Emitting Devices: Synthesis, Properties and Applications"

Abstract: 1 Inorganic Semiconductors for Light-emitting Diodes (E Fred Schubert, Thomas Gessmann, and Jong Kyu Kim) 11 Introduction 12 Optical Emission Spectra 13 Resonant-cavity-enhanced Structures 14 Current Transport in LED Structures 15 Extraction Efficiency 16 Omnidirectional Reflectors 17 Packaging 18 Conclusion References 2 Electronic Processes at Semiconductor Polymer Heterojunctions (Arne C Morteani, Richard H Friend, and Carlos Silva) 21 Introduction 22 Charge Capture at Polymer Heterojunctions 23 Exciton Dissociation at Polymer Heterojunctions 24 Morphology-dependent Exciton Retrapping at Polymer Heterojunctions 25 Summary Acknowledgments References 3 Photophysics of Luminescent Conjugated Polymers (Dirk Hertel and Heinz Bssler) 31 Introduction 32 Spectroscopy of Singlet States 33 Optically Induced Charge Carrier Generation 34 Triplet States 35 Resum Acknowledgement References 4 Polymer-Based Light-Emitting Diodes (PLEDs) and Displays Fabricated from Arrays of PLEDs (Xiong Gong, Daniel Moses and Alan J Heeger) 41 Introduction 42 LEDs Fabricated from Semiconducting Polymers 43 Accurate Measurement of OLED/PLED Device Parameters 44 Fowler-Nordheim Tunneling in Semiconducting Polymer MIM Diodes 45 Pixilated Displays 46 Thickness Dependence of Electroluminescence Efficiency 47 Limits on the Electroluminescence Efficiency 48 White-light emission 49 Conclusion Note Acknowledgement References 5 Metal/Polymer Interface Studies for Organic Light-Emitting Devices (Man-Keung Fung, Chun-Sing Lee, and Shuit-Tong Lee) 51 Review of Organic Light-Emitting Diodes and their Fundamental Interface Studies 52 Polymer Materials, their Preparations, and Experimental Details 53 Chemistry and Electronic Properties of Metal/F8BT 54 Role of Ytterbium and Ytterbium/Cesium Fluoride on the Chemistry of F8BT 55 Highly Efficient and Substrate-Independent Ytterbium/Cesium Fluoride Cathodes 56 Conclusions Acknowledgements References 6 The Synthesis of Electroluminescent Polymers (Andrew C Grimsdale) 61 Introduction 62 Poly(arylene vinylene)s 63 Poly(arylene ethynylene)s 64 Polyarylenes 65 EL Polymers with Isolated Chromophores 66 Stability of EL Polymers 67 Conclusion References 7 Charge-transporting and Charge-blocking Amorphous Molecular Materials for Organic Light-emitting Diodes (Yasuhiko Shirota) 71 Introduction 72 Amorphous Molecular Materials 73 Requirements for Materials in OLEDs 74 Amorphous Molecular Materials for Use in OLEDs 75 Charge Transport in Amorphous Molecular Materials 76 Outlook References 8 Dendrimer Light-Emitting Diodes (John M Lupton) 81 Introduction 82 The Dendrimer Concept 83 Electroluminescent Dendritic Materials 84 Electronic Properties 85 Dendrimer Devices 86 Dendronized Polymers 87 Conclusions References 9 Crosslinkable Organic Semiconductors for Use in Organic Light-Emitting Diodes (OLEDs) (Klaus Meerholz, Christoph-David Mller, Oskar Nuyken) 91 Introduction 92 Multiple-Layer Deposition 93 Patterning 94 Conclusion and Outlook Acknowledgements References 10 Hybrid OLEDs with Semiconductor Nanocrystals (Andrey L Rogach and John M Lupton) 101 Introduction 102 LEDs in the Visible based on Composites of Semiconductor Nanocrystals and Polymers or Nanocrystals and Small Organic Molecules 103 Near-infrared LEDs based on Composites of Semiconductor Nanocrystals and Polymers or Small Organic Molecules 104 Concluding Remarks References 11 Polymer Electrophosphorescence Devices (Xiaohui Yang and Dieter Neher) 111 Introduction 112 Phosphorescent Dyes 113 Transfer Processes in Polymer Hosts Doped with Phosphorescent Dyes 114 Polymer Phosphorescence Devices based on PVK 115 Phosphorescent Devices with Other Host Polymers 116 Fully Functionalized Polymers 117 Conclusion and Outlook Acknowledgement References 12 Low-threshold Organic Semiconductor Lasers (Daniel Schneider, Uli Lemmer, Wolfgang Kowalsky, Thomas Riedl) 121 Introduction 122 Fundamentals of Organic Semiconductor Lasers 123 Low-threshold Organic Lasing 124 Comparison of Organic Laser Properties 125 Electrically Driven Organic Lasers 126 Summary and Outlook References Subject Index