Interfacial‐Tunneling‐Effect‐Enhanced CsPbBr3 Photodetectors Featuring High Detectivity and Stability. (10th October 2019) - Zeng, Junpeng
Abstract: Inorganic halide perovskite (HP)‐based photodetectors (PDs) have exhibited fast response speed and high responsivity, but with low detectivity due to the high dark current of devices. Additionally, the intrinsic instability of HPs and interface deterioration originating from ion migration inhibit their practical applications severely. A tunneling organic layer is introduced to solve both these problems. Light‐induced charge carriers can flow across the interfacial (poly(methyl methacrylate), PMMA) layer with appropriate thickness via the Fowler–Nordheim tunneling effect. Due to the effective control of dark current, the photo‐/dark‐current ratio reaches a giant value of 2.13 × 10 8, and the peak detectivity is as high as 1.24 × 10 13 Jones. With such superiority, light signal as weak as 244 pW is accurately imaged by a PD array. Additionally, the hydrophobic organic layer inhibits the destruction of HPs caused by moisture and ion migration induced interface reaction, and negligible response attenuation is observed during continuous work in a humid environment for 48 h. This heterojunction structure design provides a new strategy to enhance the performance and stability of perovskite‐based photoelectric and photovoltaic devices. Abstract : High‐performance all‐inorganic halide perovskite cesium lead bromide (CsPbBr3 ) photodetectors are constructed by inserting a interfacial (poly(methyl methacrylate), PMMA) layer into a p–i–n structure. Efficient tunneling and a photoelectric effect are demonstrated with high on/off ratio (2.13 × 10 8 ) and detectivity (1.24 × 10 13 Jones). Improved stability and ultraweak light detection application further show the potential of this heterojunction in the design of photoelectric and photovoltaic devices.