Hybrid Polyrhizal CdS Nanobelts/All‐Inorganic Perovskite Nanoflake Heterojunction toward Ultrahigh‐Performance Optoelectronic Devices

Abstract

Both all‐inorganic lead‐free perovskite and CdS nanobelts possess outstanding photo‐detective properties. Herein, a hybrid photodetector based on four CdS nanobelts (NBs)/Cs3Sb2Br9 nanoflake (NF) heterojunction fabricated by a dry‐transfer tactic is designed. In this structure, four parallel CdS nanobelts almost fully cover the Cs3Sb2Br9 NF so that their photoelectronic advantage is demonstrated. The Cs3Sb2Br9 is exploited as an efficient light absorber and component for the construction of type‐II energy band with CdS. Compared with a single CdS NB/Cs3Sb2Br9 NF device, the hybrid four CdS NBs/Cs3Sb2Br9 NF device increases the hybrid area ratio of the channel from 36% to 86%, and demonstrates an appealing performance on an ultrahigh ON/OFF current ratio of 1.54 × 105, remarkable responsivity of 4.13 × 103 A W−1, large detectivity of 1.47 × 1015 Jones, and tremendous external quantum efficiency of 1.14 × 106 %, which are 9.5, 3.8, 7.2, and 3.8 times greater than the single CdS NB/Cs3Sb2Br9 NF device, respectively. Moreover, the photoresponse wavelength of the hybrid four CdS NBs/Cs3Sb2Br9 NF device is broadened to 400–520 nm. This work offers a strategy to enhance the photoelectric performance of hybrid devices, along with the illustration of vital insight into advanced device designs for violet‐green photodetectors.