First principles study on strain induced structural and electronic properties of all inorganic lead-free ASnBr3 (A = Cs, Rb and K) perovskites

All inorganic halide perovskites have received tremendous significance in the perovskite solar cells (PSCs) technology. The toxicity in PSCs due to Pb element concerns to the environment, thus replacement of Pb is a prerequisite in the development of PSCs. In this study, we have studied strain-induced structural and electronic properties of lead-free ASnBr3 (A = Cs, Rb, K) perovskites using density functional theory based first principles calculation. The band gap values of these perovskites are varied from 0 to 1.14 eV within the strain range of -4 to 4%.