Screening of perovskite materials for solar cell applications by first-principles calculations

Organic−inorganic metal halide ABX3 perovskite materials have stimulated great interest because of their superior photoelectronic properties and potential solar cell applications. However, the most widely used CH3NH3PbI3 suffers from its poor stability and inclusion of toxic lead. In order to screen potential ABX3 candidate materials for solar cell applications, first-principles calculations have been performed for 90 organic-inorganic ABX3 perovskites with A cation to be one of CH3NH3, CH3CH2NH3 and CH2(NH2)2 molecules, B cation from Cd, Cu, Ge, Mg, Ni, Pb, Sn, Ti, V and Zn, and the X monovalent anion from Cl, Br and I. Some potential absorber materials with a 3D perovskite structure have been identified by using the calculated decomposition enthalpies, band gaps, and optimized atomic structures. The structural factor screening is found to be not decisive since the electronic effects are not taken into account. Furthermore, by doping at the B or X sites with a proper concentration, it is possible to improve the stability and optimize the band gap of perovskite materials. Since the present calculations are conducted for small monovalent organic molecules and the tetragonal perovskites, the present theoretical results should provide a useful guidance for designing the organic−inorganic perovskite solar cell absorbers.