Color-Tuned Perovskite Films Prepared for Efficient Solar Cell Applications

Color-tuned perovskite films have been recognized as a promising candidate for building integrated photovoltaics; bright, colorful displays; and component cells in multijunction solar cell applications. In this paper, four representative color-tuned perovskite films with chemical formula CH₃NH₃PbBr_xI_3-x (x = 0, 1, 2, and 3) are successfully prepared by using a technique that combines the advantages of direct contact lead halide film with hot methylamine halide powder and intercalcation processes. The energy-dispersive X-ray spectrometry results indicate that the Br/I ratio is controlled as desired. The scanning electron microscopy imaging shows very uniform films with good surface coverage on the substrate. The highest power conversion efficiency of the perovskite solar cells with the four different compositions are 12.76%, 6.84%, 4.12%, and 3.53%, respectively.