Technical Feature

Materials Challenges and Applications of Solution-Processed Organic Field-Effect Transistors

Henning Sirringhaus and Masahiko Ando

Abstract

Organic field-effect transistors (FETs) are currently the focus of significant academic research and industrial development interest, as they potentially offer unique advantages over their inorganic counterparts in terms of cost reductions, compatibility with low-temperature and printing-based manufacturing, and potentially even performance. The first generation of products incorporating organic FETs is presently being introduced to the market. This article provides an overview of strategies for achieving high field-effect mobilities in solution-processed organic semiconductor films. We provide an assessment of materials challenges to meet performance and reliability requirements for a range of display and circuit applications and present an overview of state-of-the-art application demonstrations in active-matrix addressing of flexible eletrophoretic, organic light-emitting diode, and liquid-crystal displays, as well as radio-frequency identification tagging. We discuss how the unique functional properties of organic semiconductors, which allow comparatively easy integration of information processing, information storage, light emission, and light detection functions, might enable multifunctional applications that are not easy to create with other material systems.

Henning Sirringhaus is the Hitachi Professor of Electron Device Physics at the Cavendish Laboratory at the University of Cambridge. He has undergraduate and PhD degrees in physics from ETH Zürich. From 1995 to 1996, Sirringhaus worked as a postdoctoral research fellow at Princeton University on a-Si thin-film transistors for active-matrix liquid crystal displays. He has been working in the field of organic transistor devices since 1997. Sirringhaus' research interests include the realization of functional nanostructures using solution self-assembly, the charge transport physics of molecular and polymeric semiconductors, the development of printing-based high-resolution patterning techniques, and the use of scanning probe techniques for electrical characterization of molecular nanostructures. He also is a co-founder and chief scientist of Plastic Logic Ltd., a technology start-up company commercializing printed organic transistor and flexible display technology for applications in electronic readers.

Masahiko Ando is a senior research scientist at the Hitachi Cambridge Laboratory, Hitachi Europe, Ltd. He obtained undergraduate and PhD degrees in physics and applied physics from the University of Kyoto and Tokyo Institute of Technology, respectively. Ando has been working in the field of thin-film devices for flat panel display applications since 1986. He has worked on thin-film electroluminescent devices, amorphous-silicon thin-film transistors, wide viewing-angle active-matrix liquid-crystal displays, and transparent conducting oxides using indium tin oxide at the Hitachi Research Laboratory, Hitachi, Ltd. In 2003, Ando moved to the Advanced Research Laboratory at Hitachi and has been working on organic thin-film transistors. In 2007, he moved to the Hitachi Cambridge Laboratory embedded in the Cavendish Laboratory, where he is working on the device physics of organic transistors in collaboration with Henning Sirringhaus' group. Ando also has been a visiting professor at the Tokyo University of Agriculture & Technology since 2003. He is a committee member of the Society for Information Display UK chapter and received the best presentation award at the 11^th International Workshop on Active-Matrix Liquid-Crystal Displays-TFT Technologies and Related Materials.