Computational Study of Structural and Electrical Properties of Methylammonium Lead Iodide Perovskite

Methyl ammonium lead iodide perovskite (CH3NH3PbI 3) plays an important role in light absorption in perovskite solar cells. The main aim of this thesis is to investigate the structural and electrical properties of cubic and tetragonal phases of CH3NH3PbI 3. The optimized structure and minimum energy lattice constants of relaxed cubic unit cells were initially computed. The most stable orientation of methylammonium cation was found to be in the [1 1 -1] direction. This directional preference is described by bonding analysis of the atomic cage of PbI3 with the C≡N dimer. The variation of c/a ratio with the distortion angle of PbI6 underlies the understanding of the transition from the cubic to the tetragonal phase.;For the equilibrium structures band structures and effective masses were computed. The computed effective masses of both holes and electrons of CH 3NH3PbI3 are comparable to the widely used silicon in commercial inorganic solar cells. These results describe the light absorption nature of methylammonium lead iodide perovskite and its importance in future solar cell technology.