Fast preparation of compact and stable perovskite films derived from PbCl2 and Pb(Ac)2·3H2O mixed-lead-halide precursors

Abstract

In this work, lead chloride (PbCl2) and lead acetate trihydrate (Pb(Ac)2·3H2O) mixed precursors are introduced to prepare perovskite films. PbCl2 has been reported to enhance crystallinity but long annealing time is required. Pb(Ac)2·3H2O is used because it is cheap and easy to get, and lead acetate offers fast crystallization process, meanwhile the trihydrate might improve the film stability. With an optimal blending ratio of the two precursors (1:1mol ratio), compact and full-coverage perovskite film with large grain sizes (>1µm) are obtained, and the speed of perovskite film formation is greatly accelerated. Moreover, the film prepared in a 1:1mol ratio of the two precursors exhibits good moisture liability for several days under around 70% RH environment. As a result, the PbCl2: Pb(Ac)2·3H2O (1:1) results in the highest efficiency of 14.77%. The findings in this work provide a facile way to improve the perovskite film quality and stability.