Low-Toxicity Antisolvent as a Polar Auxiliary Agent for High-Performance Perovskite Photodetectors

Abstract

The preparation of a high-quality perovskite film is very important for improving the device performance of perovskite photodetectors (PPDs). At present, one of the most commonly used methods to obtain high-quality perovskite films is to regulate the nucleation and crystal growth processes through antisolvent-assisted crystallization. In this work, we employ a low-toxicity antisolvent sec-pentanol (SPA) as a polar auxiliary agent to modify the perovskite films, which can effectively regulate the MAI·PbI2·DMSO intermediate phase because of its moderate polarity, leading to the formation of a uniform and pinhole-free perovskite morphology. As a result, the photoresponsivity reaches 1.06 A/W under an illumination of the 532 nm laser with a power density of 12.74 μW/cm2 at a bias voltage of -2 V, which is the known champion responsivity for vertical PD based on an indium tin oxide glass substrate and with CH3NH3PbI3 as the only photosensitive material. Moreover, we study the effects of chlorobenzene with polarity less than SPA and n-butanol with polarity greater than SPA on perovskite formation and device performance as an antisolvent and find that the crystallization quality of the perovskite film is greatly affected by the polarity of the antisolvent. This work provides a reference for the preparation of high-performance PPDs.