High Performance Hybrid-Phototransistor Based on ZnON/perovskite Heterostructure Through Multi-Functional Passivation

Organic-inorganic halide perovskites are widely investigated for various optoelectronics devices such as photodetectors and solar cells. However, Pb-based perovskite photodetectors perform poorly because of insufficient mobility and absence of an effective photoconductive gain mechanism. Herein, ZnON/perovskite heterostructures are demonstrated to realize the fabrication of high-performance hybrid phototransistors. Additionally, a guanidinium iodide (GuI), alternating-cation-interlayer (ACI)-type organic spacers, are utilized as an interface passivation layer. It is shown that the GuI interface layer reduces the defect density of the ZnON surface as well as the bulk perovskite film and promotes the separation and transport of photo-generated charge carriers. Devices fabricated with the GuI interface passivation layer have a response speed of 0.1 s, excellent responsivity of 5.97 x 106 A W-1, and ultra-high specific detectivity of 1.28 x 1018 Jones, the highest value among previously reported perovskite-based hybrid phototransistors. This work provides valuable insights into the design and fabrication of high-performance metal oxide/perovskite heterostructures with promising applications in future optoelectronic devices. Employing multi-cation engineering, solvent engineering, and phase engineering, ZnON/FACsPbI3 heterostructures are fabricated and applied to hybrid phototransistors. A GuI interface layer is introduced to alleviate the defects that exist in the hetero-interface. The impact of the GuI interface layer on the ZnON/FACsPbI3 heterostructure is investigated. Hybrid phototransistors based on ZnON/FACsPbI3 heterostructure exhibit ultra-high specific detectivity and rapid response time.image