有机金属卤化物钙钛矿发光场效应晶体管

Organic light emitting field-effect transistors (OLEFETs) are an emerging class of multifunctional optoelectronic devices that combine the electrical switching and current modulating functionalities of a field-effect transistor with the capability of electroluminescence from an organic light-emitting diode (OLED) in a single device architecture. OLEFETs have advantages over OLEDs including gate-tunable EL, minimized exciton losses, and potentially higher EL quantum efficiency inherent to device structures. As one of the simplest integrated organic optoelectronic devices possessing unique EL properties, OLEFETs have potential applications in active matrix full color electroluminescent displays, sensors, and electrically pumped organic lasers. In general, it is required that organic semiconductors in OLEFETs should possess both efficient field-effect and EL characteristics in order to achieve high device performance. Unfortunately, there are few ambipolar organic semiconductors with sufficiently high mobility and EL efficiency. Further development is limited by low field-effect mobilities of well-established OLED materials and poor EL efficiencies of outstanding OFET materials. In this project, in order to achieve efficient electroluminescence at high current densities, we introduce distributed Bragg reflector (DBR) into a bottom-gate architecture and design novel light emitting field-effect transistors with DBR as a dielectric or a DBR microcavity based on organometal halide perovskites, which have excellent physical properties, such as ambipolar carrier transport, high mobility, tunable band gap, and high luminescence efficiency. We investigate their electrical and luminescent characteristics and study the working mechanisms of the devices including charge carrier injection, transport, exciton recombination, light emission, amplified spontaneous emission, and simulated emission. It is expected to realize electrically pumped lasers in light emitting field-effect transistors based on organometal halide perovskites.

有机发光场效应晶体管集有机发光二极管的发光功能和场效应晶体管的开关功能于一体，是实现高效率高亮度电致发光，甚至电泵浦有机激光的最有效的技术途径之一。但材料是制约有机发光场效应晶体管发展的瓶颈，同时具有优良的载流子输运特性和高发光效率的有机材料几乎没有。有机金属卤化物钙钛矿独特而优良的光电特性，如双极载流子输运、高迁移率、灵活可调的直接带隙结构及高发光效率等，满足发光场效应晶体管对沟道材料的要求。本项目在制备高结晶度有机金属卤化物钙钛矿薄膜的基础上，对DBR谐振腔的光学功能与场效应晶体管绝缘栅的电学功能作一体化设计，构建新型DBR绝缘栅发光场效应晶体管和DBR微腔结构发光场效应晶体管，实现高电流密度驱动下的高效电致发光，深入认识器件工作的物理过程，澄清其中的关键物理问题，如钙钛矿的结构及形貌对载流子输运和复合发光的影响、放大自发辐射和受激辐射的增益和损耗等机制，探索实现电泵浦激光的可行途径。