Temperature-dependent photoluminescence on organic-inorganicmetal halide perovskite CH₃NH₃PbI_3-xCl_x prepared onZnO/FTO substrates using a two-step method

Temperature-dependent photoluminescence characteristics of organic-inorganic halide perovskite CH₃NH₃PbI_3-xCl_x films prepared using a two-step method on ZnO/FTO substrates were investigated. Surface morphology and absorption characteristics of the films were also studied. Scanning electron microscopy revealed large crystals and substrate coverage. The orthorhombic-to-tetragonal phase transition temperature was ~140 K. The films' exciton binding energy was 77.6±10.9 meV and the energy of optical phonons was 38.8±2.5 meV. These results suggest that perovskite CH₃NH₃PbI_3-xCl_x films have excellent optoelectronic characteristics which further suggests their potential usage in perovskitebased optoelectronic devices.