Wu Jianghong, Qiu Caiyu, Feng Sirui, Yao Tianyi, Yan Yanfei, Lin Shisheng
College of Microelectronics, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China.
Nanotechnology. 2019 Nov 21;31(10):105204. doi: 10.1088/1361-6528/ab5a08.
Photodetectors based on graphene/GaAs heterostructure were fabricated and demonstrated for application in self-powered photodetection. Then, Si quantum dots (QDs) were spin-coated onto the surface of the devices to enhance the built-in field by photo-induced doping, because of the tunable Fermi level (E ) of graphene and shallow junction of the heterojunction. Additionally, Au nanoparticles working as a light trapping structure were used to the enhance quantum efficiency of the Si QDs and the optical absorption of the heterojunction, benefitting from localized surface plasmon resonance. Therefore, a large-area photodetector under self-powered conditions achieved a high performance i.e. responsivity (1.81 × 10 V W), detectivity (2.0 × 10 Jones), fast response speed (<0.04 ms), and on-off ratio (6 × 10). The high voltage responsivity opens a promising pathway to ultra-weak light detection, and facilities the development of novel sensors.
制备了基于石墨烯/砷化镓异质结构的光电探测器，并展示了其在自供电光电探测中的应用。然后，由于石墨烯的费米能级（E）可调以及异质结的浅结特性，通过光诱导掺杂将硅量子点（QDs）旋涂到器件表面，以增强内建电场。此外，由于局域表面等离子体共振，用作光捕获结构的金纳米颗粒被用于提高硅量子点的量子效率和异质结的光吸收。因此，一种大面积自供电条件下的光电探测器实现了高性能，即响应度（1.81×10 V/W）、探测率（2.0×10 Jones）、快速响应速度（<0.04 ms）和开/关比（6×10）。高电压响应度为超弱光探测开辟了一条有前景的途径，并推动了新型传感器的发展。
