Abstract: It is an effective way to improve the photoelectric conversion efficiency of perovskite solar cells by cutting down the band gap of perovskite and broadening the range of optical absorption.In this paper, formamidine triiodoplumbite (HC(NH2)2PbI3 or FAPbI3) precursor solution mixed with a certain proportion of methyl ammonium iodide (CH3NH3I or MAI) and the annealing temperature of perovskite thin film is reduced from 150 ℃ to 100 ℃.The surface morphology and crystallinity of the films can not only effectively improve, but also get more than methyl ammonium triiodoplumbite (CH3NH3PbI3 or MAPbI3) narrow gap the film.The efficiency of perovskite photovoltaic cells is 14.8;.

Key words: It is an effective way to improve the photoelectric conversion efficiency of perovskite solar cells by cutting down the band gap of perovskite and broadening the range of optical absorption.In this paper, formamidine triiodoplumbite (HC(NH2)2PbI3 or FAPbI3) precursor solution mixed with a certain proportion of methyl ammonium iodide (CH3NH3I or MAI) and the annealing temperature of perovskite thin film is reduced from 150 ℃ to 100 ℃.The surface morphology and crystallinity of the films can not only effectively improve, but also get more than methyl ammonium triiodoplumbite (CH3NH3PbI3 or MAPbI3) narrow gap the film.The efficiency of perovskite photovoltaic cells is 14.8;.