Ultrastable Lead‐Free Double Perovskite Photodetectors with Imaging Capability. Issue 10 (29th March 2019) - Li, Ying
Abstract: Recently, the halide perovskites have increasingly received attention because of their superior capabilities in photodetector applications. However, the well‐known instability and lead‐toxicity are two major obstacles for their commercialization and practical applications. In this work, self‐powered photodetectors based on solution‐processed double perovskite Cs2 AgBiBr6 films are fabricated for the first time. Owing to the high material integrity of Cs2 AgBiBr6 and efficient interfacial charge transfer from perovskite to the underlying electron‐quenching layer, the photodetector demonstrates excellent performances. Especially, the unencapsulated device demonstrates a good working stability in the open air. Typically it has the ability to endure a high temperature of 373 K for 10 h continuous running, demonstrating a good temperature resistance. In addition, after 3‐month storage in open air, the photodetection capability of the device can almost be maintained. By deploying the photodetector as a point‐like sensing pixel, high‐resolution imaging patterns are acquired, which is the first report on imaging applications of lead‐free perovskite photodetectors. The obtained results suggest that the lead‐free double perovskite Cs2 AgBiBr6 is potentially an attractive candidate to be applied in high‐efficiency and stable photodetectors that can be employed in optical imaging. Abstract : A self‐powered perovskite photodetector is demonstrated by employing solution‐processed lead‐free double perovskite Cs2 AgBiBr6 films as the light absorber, and an excellent photodetection performance is achieved. The unencapsulated device demonstrates a remarkable operation stability over the long‐term temperature endurance test in air ambient and high temperature (373 K). Further, the capability of the photodetector for projection imaging applications is evaluated.