Laser deposition for the controlled co-deposition of organolead halide perovskite

A laser deposition system for the co-evaporation of organolead halide perovskite was developed. We successfully demonstrated that the difficulty in deposition control of CH3NH3I (MAI) was overcome by laser deposition, where the evaporation rate was finely adjusted by tuning the duty ratio of squarely modulated infrared laser. Deposition rate was stabilized for several-hour co-deposition period. The laser deposition method enabled the stoichiometric control of MAI and PbI2 with sufficient reproducibility. Planar type perovskite solar cells were constructed with the use of p-type and n-type organic semiconductor as buffer layers and the efficiency of 16.0 % with reduced hysteresis was achieved.