High detectivity and fast response avalanche photodetector based on GaSe/PtSe2 p–n junction
Kaiwen Gong, Lianbi Li, Wenzhi Yu, Haoran Mu, Jian Yuan, Ran Hao, Baiquan Liu, Zengxia Mei, Luyao Mei, Haozhe Li, Shenghuang Lin
Abstract
Heterojunction photodetectors based on 2D materials are a promising geometry to acquire broadband photodetection with combination of wide-bandgap and narrow bandgap functional materials. But the interface condition of the heterojunction is difficult to control due to the inevitable introduction of air bubbles and wrinkles. In this paper, a synthesis method merging exfoliation and CVD is reported to fabricate photodetectors of the GaSe/PtSe2 heterojunction. The devices present the highest responsivity and detectivity of about 1.7 A/W and 3.51 × 1012 Jones at a −10 V bias under the avalanche mode, respectively. Also, a fast response time could be obtained around 20 μs. In addition, the photodetector exhibits a clear photovoltaic effect, which can work in a self-powered mode.