Understanding the limit and potential in emerging perovskite solar cells

In this contribution we give an overview of the recent development of metal-halide perovskite solar cells. We focus on the mixed electronic-ionic conductivity of this material, which causes hysteresis in the current-voltage curve. We discuss latest results on recombination obtained by electroluminescence measurements. We report on high luminescence yields (1%) and open-circuit voltages larger than 1.2 V, which are exceptional for a material with a bandgap of 1.6 eV and yield to efficiencies >21%. We identify the efficiency limiting processes and propose measures to overcome those.