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 V_ds and V_gs. This work offers a valuable strategy and a practical scheme that can be generalized to other perovskite and heterostructure devices.