High performance photodetectors by integrating CsPbBr3 perovskite directly on the germanium wafer

Abstract

Lead halide perovskites are a promising candidate for the development of novel optoelectronic devices. Although substantial development has been achieved after years of research, it is still a challenge to prepare large-area high-quality CsPbBr3 thin films by simple processes. In this work, CsPbBr3 film can be used as a UV–Vis absorption active layer of heterojunction photodetector and a Ge-based infrared anti-reflective coating to optimize the photodetection performance of the device. CsPbBr3/p-Ge heterojunction photodetector exhibits self-powered (0 V) and broadband characteristics (365–1550 nm), the responsivity is 64 mA/W and the specific detectivity is 1.2 × 1012 Jones under 0 V bias and 1550 nm illumination. The rise and decay times of the device are 12.3 μs and 13.4 μs under 1310 nm illumination and 20 kHz operating frequency, respectively. This work further promotes the potential application and development of CsPbBr3 perovskites in integrated optoelectronic devices.