基于异质结有机发光场效应晶体管的电泵浦有机激光探索研究

To achieve electrically pumped organic lasers (EPOLs) is one of the most important challenges for organic optoelectronics. EPOLs based on organic light-emitting diodes ubiquitously show large excitonic non radiative loss as well as optical loss from the resonators, resulting in an extremely high current threshold compared to the normal operating range for the devices. Aiming at this tough problem, both promotion of the device current level and reduction of the device optical and electrical loss are considered in this project. Heterostructured organic light-emitting field effect transistors (HOLEFETs) is proposed as a new device platform to build organic electroluminescence devices with both high current density as well as good emission characteristics, by taking advantage of the horizontal transport property of the carriers in HOLEFETs. Furthermore, the key technical problems of structural design and fabrication for high Q planar microcavity can be solved and microcavity HOLEFETs with ultra high Q factor are expected to be constructed by utilizing the flexible structures for the active layers of HOLEFETs. Meanwhile, strategy of triplet regulation to reduce the excitonic non radiative loss of the devices by using fluorescent materials with high exciton utilization efficiency is carefully studied. On this foundation, the feasibility of demonstrating EPOLs based on high Q microcavity HOLEFETs is further explored. The development of this project is expected to drive the advances for organic optoelectronic devices and the related integration technology.

实现电泵浦有机激光（EPOLs）是有机光电子领域的重要挑战之一。基于有机发光二极管结构的EPOLs普遍存在大的激子非辐射损耗和谐振腔光学损耗，导致其阈值电流密度远超器件正常工作范围。针对这一难题，本项目从提升器件电流水平和减小器件光电损耗两方面着手，提出采用异质结有机发光场效应晶体管（HOLEFETs）作为全新器件平台，利用其独特的载流子水平传输特性，构建具备高电流密度与良好发光特性的有机电致发光器件；进一步，利用其功能层结构灵活的特点，解决当前高Q值平面微腔器件结构设计与制备关键技术问题，构建极高Q值微腔HOLEFETs；同时，利用高激子利用率荧光材料调控三线态激子，减小器件激子非辐射损耗。在此基础上探索实现基于高Q值微腔HOLEFETs 结构EPOLs的可能性。本项目的顺利开展有望为有机光电子器件及集成技术的发展提供重要的推动作用。

有机半导体激光由于材料丰富、光谱可调、易加工等特点，在发展小型可调谐激光器、柔性激光器以及光电子集成器件方面具有广阔的应用前景。本项目针对电泵浦有机激光研究中面临的超高阈值电流密度难题，从提升器件电流水平、减小器件光电损耗方面着手，采用有机发光晶体管（OLEFETs）作为新的器件平台，构建了具备高迁移率与发光效率、低效率滚降特性的有机电致发光器件。同时，利用高激子利用率荧光材料调控三线态激子，进一步减小器件激子非辐射损耗。系统优化了OLEFETs器件结构及制备工艺，获得了6%以上的外量子效率和0.5 cm-2V-1s-1以上的载流子迁移率，并成功采用具有高三线态激子利用率的杂化局域-电荷转移态材料作为发光层，获得了~1.5%的外量子效率，器件表现出低的效率滚降特性。此外，我们还发现OLEFETs能同时表现出出色的光探测特性。通过系统研究OLEFETs的光响应行为，得到了最高45300%的光-电转换效率和毫秒级的响应速度。在本项目的支持下，共发表相关SCI论文3篇。