Multicolor Broadband and Fast Photodetector Based on InGaAs–Insulator–Graphene Hybrid Heterostructure
Gaoqi Cao, Fang Wang, Meng Peng, Xiumei Shao, Bo Yang, Weida Hu, Xue Li, Jing Chen, Yabin Shan, Peisong Wu, Laigui Hu, Ran Liu, Haimei Gong, Chunxiao Cong, Zhi‐Jun Qiu
Abstract
Abstract Broadband light detection is crucial for a variety of optoelectronic applications in modern society. As an important‐near infrared (NIR) photodetector, InGaAs PIN photodiodes demonstrate high detection performance. However, they have a limited response range because of optical absorption by the window layer or substrate. To exploit the broadband absorption capability of narrow‐bandgap InGaAs, a phototransistor based on a hybrid InGaAs‐SiO 2 ‐graphene heterostructure is presented. In this system, graphene serves as a transparent conducting channel to sense optical absorption in the InGaAs. In contrast to InGaAs PIN photodiodes, the hybrid InGaAs phototransistor demonstrates multicolor photodetection over a broadband wavelength range from the ultraviolet to NIR. Furthermore, it manifests a high photoresponsivity of above 10 3 A W −1 under weak light irradiation, a large external quantum efficiency, and a fast response speed of 200 kHz. The results pave the way for the development of high‐performance broadband photodetectors based on mixed‐dimensional heterostructures.