Li Wang, Jing-Jing Li, Qi Fan, Zheng-Feng Huang, Ying-Chun Lu, Chao Xie, * Chun-Yan Wu, Lin-Bao Luo1,*

Abstract:Light detection in the near-infrared (NIR) region is of particular importance due to its wide applications in both military and civil purposes. In this study, we report on the fabrication of high-performance NIR photodetectors by simply transferring multilayered PtSe2 film onto Ge wafer to form vertical hybrid heterojunctions. Such heterojunctions exhibit apparent photovoltaic effect under NIR illuminations, offering our devices with the opportunity to operate without external power supply. Further optoelectronic analysis finds that the devices are highly sensitive to 1300, 1550, 1650 and even 2200 nm NIR illuminations with good reproducibility and long-term air stability. Upon 1550 nm irradiation, the NIR photodetectors attain high responsivity and specific detectivity of 602 mAW^-1 and 6.3×10¹¹ Jones, respectively, along with a fast response speed of 7.4/16.7 μs, at zero bias. Given the excellent photoresponse performance and the simple device geometry, the present self-driven NIR photodetectors are very promising for application in future optoelectronic devices and systems.