TDDFT Investigation of the Hybrid Organic Inorganic Perovskite: CH3NH3PbC3

Hybrid organic-inorganic metal perovskites (chemical formula: ABX3, A-organic cation, B-metal ion, X-halide) are the latest advancement for increasing efficiency in thin-film solar cells or Dye Solar Cells (DSC). They have become the fastest growing technology in solar cells, rising in efficiency from 3% to 22.7% in less than a decade. This work focuses on a time-dependent density-functional theory (TDDFT) study of \pmbCH₃NH₃PbCl₃ -methyl ammonium lead chloride- a perovskite material of potential and current research interest. The work focuses on the cubic phase. Electronic and optical properties including transition energy, band gap, and vibrational frequencies are examined. The Density of States (DOS) spectrum, IR and UV-VIS spectra are calculated. It is observed that the cubic phase of CH₃NH₃PbCl₃ shows responsivity for optical excitation between wavelength ranges from 180 nm to 350 nm, with the peak observed at 240 nm. This work will help significantly to understand charge transport and optical properties, and design optimized solar cells involving these materials.

I. Introduction

The first perovskite material, was discovered almost two hundred years ago by Lev Perovski and it was named after him. Since then any compound crystallizing in the same structure as has been classified as a perovskite. The first time a perovskite material was used in a solar cell was by Miyaska et. al. [1] in 2009 and had an efficiency of about 3.8%. Since then relentless research has been done on different configurations of perovskite materials to commercialize them. Initially, perovskite solar cells faced a stability challenge because they were very prone to environmental and other factors. However, the stability of the cells was greatly increased over the last few years. One of the most recent stable perovskite solar cell lasted for about ten thousand hours-more than a year [2], while among the most recent efficiency recorded was 22.7% [3].