红外光敏型石墨烯/量子点晶体管的超快响应研究

Recently, great breakthroughs have been made in graphene/quantum dot field effect phototransistor. Those devices have gradually become an important branch of infrared detector, due to the miniaturization, flexibility, easy integration, low working voltage and room temperature operation. However, their response time is too long, in second or sub-second time scale, to hamper high-speed applications, which do not fully reflect graphene inherent ultrahigh mobility properties..To solve that problem, based on the methodology of analysis and experiment, the tunneling structure of graphene and quantum dots is presented, where the photo induced carriers pass through from QDs to graphene via quantum resonant tunneling, so as to realize the ultrafast infrared response detection..Starting from materials, structures, and photosensitive mechanisms, this application firstly investigate the effect of matching degree between graphene and QW-QD structure on tunneling, secondly investigate the influence of structure on tunneling and optimize the parameters, thirdly investigate the role of photo generated carriers on tunneling current. This project will provide theoretical and technical support for practicality, the results have broad applications in ultrafast optoelectronics devices and systems.

石墨烯/量子点复合红外光敏场效应晶体管的研究已有很大突破，加之小型化、可柔性、集成化、低工作电压和室温工作等优点，已经逐步成为红外探测发展的一个重要方向。但是其响应时间仍处于秒或亚秒量级，不能满足高速器件的要求且未能将石墨烯高速响应的优势充分发挥出来。为解决此类器件响应慢的问题，在深入分析光探测过程的基础上，提出了通过构建石墨烯与量子点之间的隧穿结构以实现光生载流子的共振隧穿来提高响应速率，从而实现该体系的超快红外响应。该项申请从材料、结构和光敏性的角度展开研究，即a)研究量子点及其形成的量子阱结构与石墨烯之间的能级匹配度对共振隧穿的影响和作用，b)研究共振隧穿结构对共振的影响和作用，并确定最佳的结构参数，c)研究光场作用下光生载流子对隧穿电流的贡献和影响，以期获得超快响应红外响应。本项目将为器件实用化提供理论及技术支持，研究结果将在超快光电器件及系统中有广泛的应用前景。

石墨烯/量子点复合红外光敏场效应晶体管的研究已有很大突破，加之小型化、可柔性、集成化、低工作电压和室温工作等优点，已经逐步成为红外探测发展的一个重要方向。但是在立项之初的2017年，器件的响应时间仍处于秒或亚秒量级，不能满足高速器件的要求且未能将石墨烯高速响应的优势充分发挥出来。经过3年的研究，我们从器件材料的选取，异质结构的设计和构造，以及器件的优化角度，提升探测器的响应速度、平衡其探测度。最终实现了探测度10mA/W，响应时间小于20ns的超快响应的红外探测器。并取得了一些的成果，共发表SCI期刊论文20余篇（其中10篇一区论文），会议论文8篇。总结并整理出超快响应红外器件的设计方案和一整套化学方法的器件制备工艺，为器件实用化提供理论及技术支持，研究结果将在超快光电器件及系统中有广泛的应用前景。