Temperature-dependent photoluminescence on organic inorganic metal halide perovskite CH3NH3PbI3–x Cl x prepared on ZnO/FTO substrates using a two-step method*

Temperature-dependent photoluminescence characteristics of organic-inorganic halide perovskite CH3NH3PbI3-xClx 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 similar to 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 CH3NH3PbI3-xClx films have excellent optoelectronic characteristics which further suggests their potential usage in perovskitebased optoelectronic devices.