Degradation behaviors of photoelectrical properties of mixed cation perovskite solar cells under equivalent 1 MeV electron irradiation

Perovskite solar cells have excellent photoelectric properties, but their physical mechanism of anti-irradiation is still incomplete. In this work, we investigate the photoelectrical properties of mixed cation perovskite solar cells by performing electron irradiation experiments, characterization measurements (i.e. photoluminescence spectra, UV–vis absorption spectra, and quantum efficiency spectra), and Monte Carlo simulation analysis. It is found that the electrical performance of solar cells degrades more severely with increasing electron irradiation fluence. Specifically, the open-circuit voltage independent of the electron irradiation is attributed to the stability of perovskite materials. The short-circuit current density (alternatively, photoelectric conversion efficiency) of irradiated solar cells decreases because two main reasons: the blackening of the glass substrate hampers the short-wavelength light to reach the photosensitive layer, and the Au electrode has a large number of recombination centers to shorten the carrier lifetime. It is suggested that the mixed cation perovskite solar cell has anti-electron irradiation performance by adopting the anti-irradiation glass and electrode.