Electronic properties of Pb-I deficient lead halide perovskites

The electronic structure evolution of deficient halide perovskites with a general formula (A,A')_1+xM_1-xX_3-x was investigated using the density functional theory. The focus is placed on characterization of changes in the bandgap, band alignment, effective mass, and optical properties of deficient perovskites at various concentrations of defects. We uncover unusual electronic properties of the defect corresponding to a M-X vacancy filled with an …