Interface Engineering to reduce non-radiative recombination losses at the perovskite/C60 interface in monolithic perovskite silicon tandem solar cells:

Metal halide perovskites have emerged in recent years as a promising absorber material for solar cells with the potential to combine high power conversion efficiency with low production costs. However, significant non-radiative charge carrier recombination occurs at the perovskite interface to the contacts, thus preventing the full potential of the solar cell from being exploited. Photoluminescence quantum yield measurements clearly show that the Quasi-Fermi level splitting is reduced by evaporation of the electron contact C60 onto perovskites, leading to limited open-circuit voltage in devices. In recent literature, as well as in our investigations, different passivation layers are deposited between perovskite and the electron contact to reduce non-radiative recombination and to improve the open-circuit voltage. This is on the one hand pursued by increasing the selectivity at the contacts through field effects and band alignment and secondly by reducing defects at the interface through chemical passivation.