Improvement of Photoluminescence of Perovskite CH_3NH_3PbI_3 by Adding Additional CH_3NH_3I during Grinding

The organic-inorganic hybrid perovskite CH_3NH_3PbI_3 has been a good candidate for many optoelectronic applications such as light-emitting diodes due to its unique properties. Optimizing the optical properties of the CH_3NH_3PbI_3 material to improve the device performance is a hot topic. Herein, a new strategy is proposed to enhance the light emission of CH_3NH_3PbI_3 phosphor effectively. By adding the reactant CH_3NH_3I powder in an appropriate proportion and simply grinding, the emission intensity of CH_3NH_3PbI_3 is greatly improved. The advantages of the proposed method are swiftness, simplicity and reproducibility, and no requirement for a complex organic ligand. The mechanism of this phenomenon is revealed by x-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, photoluminescence, and temperature-dependent photoluminescence. This study offers a unique insight for optimizing the optical properties of halide perovskite materials.