Direct or Indirect?: Unraveling the bandgap nature of metal halide perovskites

Since the discovery of the photovoltaic properties of metal halide perovskites in 2009, the material has rapidly gained interest in the scientific community. In less than 10 years, the power conversion efficiency of perovskite solar cells (PSC) has increased from 3.9% to over 25%, reaching levels of conventional silicon cells. PSCs have multiple...