Melamine Hydroiodide Functionalized MAPbI3 Perovskite with Enhanced Photovoltaic Performance and Stability in Ambient Atmosphere

Abstract

Despite the remarkable performance of organometallic halide perovskite solar cells (PSCs), their ultimate stability is still a major issue that inhibits the commercialization of this eminent technology. Herein, melamine hydroiodide (MLAI) is added to function methyl ammonium (CH3NH3+, MA+) lead iodide perovskite for fabricating structured perovskite with enhanced photovoltaic performance and stability in the harsh ambient atmosphere (35 °C, 60–70% relative humidity). Nearly no new phase formed even incorporated 25 mol.% MLAI induces the strain in the perovskite crystal structure. The MLAI-structured perovskite film shows a denser and smoother surface than the pristine MAPbI3 perovskite. Planar PSCs based on 2 mol.% MLAI-functionalized perovskite show 17.2% power conversion efficiency with nearly no hysteresis which is much higher than pristine MAPbI3 PSCs. Most importantly, the solar cell devices based on 2 mol.% MLAI-functionalized perovskite still retain over 90% of the initial performance after being kept in ambient atmosphere for more than 560 h without encapsulation.