Long‐Term Stable and Tunable High‐Performance Photodetectors Based on Perovskite Microwires

Abstract Oraganolead halide perovskites (OHPs) present remarkable optoelectronic properties, and thus possess extensive applications in photovoltaic devices and photodetectors. However, the OHP‐based devices severely suffer from low environmental stability because of water invasion and oxygen erosion to the materials. In this work, this challenge is overcome by utilizing the unique advantages of the microwire structure. OHP microwires, which can be fabricated by simple and low‐cost dip coating method, present superior resistance to moisture as compare to conventional OHP films or nanowires, thanks to their combined properties of high‐crystallinity and low surface‐to‐volume ratio. Photodetectors based on the OHP microwires show outstanding long‐term stability over 90 d even stored with high relative humidity, which is among the highest stability according to the literature reports. Meanwhile, the photodetectors exhibit high and tunable sensory performance by adjusting the distribution of OHP microwires through changing the dip‐coating parameters, for example, the light‐to‐dark current ratio of the device can be over 20 000. The photodetectors with OHP microwaves deposited on polymer substrates also exhibit great mechanical flexibility. Therefore, this work reveals the unique advantages of the low‐cost and readily‐fabricated OHP microwires, and demonstrates their promising applications in optoelectronic devices by developing long‐term stable and tunable high‐performance photodetectors.