Structural and Optoelectron Properties of Hybrid Perovskite Crystals

The structure and photoluminescence of CH 3 NH 3 PbI 3 (lead triiodide methylammonium) synthesized perovskite crystals are investigated in a wide temperature range. As temperature rises to 130–140 K, there is a junction from an orthorhombic to tetragonal crystal lattice with a change in the bandwidth. An increase in the stationary photoluminescence intensity at room temperature under the influence of exciting emission is revealed. A model explaining the observed growth of photoluminescence is proposed.