Achieving Low Cost and High Performance Flexible CsPbIBr2 Perovskite Photodetectors Arrays with Imaging System via Dual Interfacial Optimization and Structural Design

Abstract

AbstractAll‐inorganic metal halide perovskites are competitive candidate as next‐generation flexible photodetectors (PDs) materials due to the remarkable photoelectric properties, enhanced heat stability, and mechanical flexibility. However, constructing low‐cost flexible perovskites PDs with high photodetection performance, good operation stability and mechanical robustness, and manufacturing corresponding flexible PDs array have been a challenge. Herein, the PbCl2 and Zinc(II) Dibenzyldithiocarbamate (Zn(DBDTC)2) are employed to modify bottom and top interface of CsPbIBr2 perovskite layer, respectively, to passivate surface trap state, enhance hydrophobicity and resist phase segregation, and improve interface contact. Consequently, the self‐powered champion PDs with low‐cost Bi2Te3 electrode reach a responsivity of 0.38 A W−1 and a maximum detectivity of 3.44 × 1013 Jones at 570 nm, and maintain the outstanding long‐term and operational stability without additional encapsulation. Meanwhile, the HTL‐free flexible PDs based on low‐temperature CsPbIBr2 perovskite layer exhibit impressive photodetection performance and mechanical robustness in bending test. More importantly, the flexible PDs array (5 × 5 pixels) and corresponding imaging system are fabricated with uniform and clear imaging results under flatting and bending state. This research is of great significance for the application of stable and high‐performance inorganic perovskites PDs and flexible array imaging systems.