Performance‐Enhanced CsPbBr₃/HfO₂/Si Heterostructure Optoelectronics through the Tunneling Effect

Abstract

CsPbBr3, as an all‐inorganic perovskite, has attracted considerable research interest due to its excellent optoelectronic properties. However, because the electronic properties of CsPbBr3 are not satisfactory, the relatively low on/off ratio and long photoresponse time of CsPbBr3 devices limit further applications. In this work, a CsPbBr3 device with high performance is successfully fabricated through a simple process using a CsPbBr3 colloid, and the photoresponse performance of the device is investigated under different external factors. By inserting a thin HfO2 layer, CsPbBr3‐based heterostructure devices exhibit much better performances, including an enhanced photocurrent of ≈10 µA, a responsivity of 45.05 A W−1, a detectivity of 9.12 × 1010 Jones, an external quantum efficiency of 12445%, and rise/fall times of 600 µs/300 µs, respectively. A physical mechanism is proposed to explain the photoresponse property promotion in CsPbBr3 devices, which can be attributed to the tunneling effect between CsPbBr3 and Si through the thin HfO2 layer. More importantly, the optoelectrical properties of the proposed CsPbBr3/HfO2/Si heterostructure device can be modulated through both Vds and Vgs. This work offers a valuable strategy and a practical scheme that can be generalized to other perovskite and heterostructure devices.