Optical properties of organometal halide perovskite thin films and general device structure design rules for perovskite single and tandem solar cells

The optical constants of a CH3NH3PbI3-xClx perovskite thin film were acquired for the first time. With this optical constant information, detailed optical modelling and optimization were performed and the calculations suggest that power conversion efficiencies of up to 20% and 29% are feasible in planar-type single and tandem cells.