High‐Speed Broadband Hybrid Perovskite Nanocrystals /Ge Photodetector from UV to NIR

Abstract High speed broadband photodetectors (PDs) have attracted significant interest for many applications such as imaging, gas sensing, and night vision. In this study, the widest reported detection range is achieved from 254 nm to 1800 nm by integrating CsPb(BrCl) 3 : Yb 3+ nanocrystals (NCs) with Germanium (Ge) on a Si substrate. To overcome the persistent photoconductance (PPC) effect that limits the detector response speed in the UV region, this study proposes a down conversion technology to convert UV light to 980 nm infrared light by applying a CsPb(BrCl) 3 : Yb 3+ NCs. The response time of the hybrid PD at 275 nm decreased significantly from several hundred seconds to 1.21 µs. Moreover, benefiting from the CsPb(BrCl) 3 : Yb 3+ NCs antireflection layer, the responsivity of a hybrid CsPb(BrCl) 3 : Yb 3+ NCs /Ge metal semiconductor metal (MSM) PD has enhanced the whole detection band, especially at 1310 nm, which increased by 80% from 0.16 to 0.29 A W −1 . This work promotes the development of perovskite integrated optoelectronic devices and provides a feasible route for broad‐band PD from the UV to near infrared (NIR) band.