Rapid and Complete Conversion of CH3NH3PbI3 for Perovskite/C60 Planar-Heterojunction Solar Cells by Two-Step Deposition

In the present work, we proposed an improved two-step deposition method by optimizing the reaction temperature and the dipping time for the fabrication of perovskite films.The perovskite film fabricated at 70.exhibits a full surface coverage and a smooth uniform crystal morphology with a particle size up to micrometer scale.The corresponding inverted perovskite solar cell with a structure of ITO/poly(3,4-ethylenedioxythiophene): poly(styrene-sulfonate)(PEDOT: PSS)/CH3NH3PbI3/C-60/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)/Ag displayed a higher power conversion efficiency (PCE) of 13.6% than that of the device fabricated at 20 degrees C(8.06%), as well as the high reproducibility.The small but meaningful modification for two-step deposition would provide an efficient and convenient way to optimize planar perovskite solar cells and facilitate the potential applications of perovskite solar cells more widely.