The influence of fullerene on hysteresis mechanism in planar perovskite solar cells

Despite the rapid development of perovskite devices, the current density-voltage hysteresis still needs to be conquered. Here, the introduction of PCBM into the active layer of planar perovskite solar cells is carried out and hysteresis-free devices are produced. A photoluminescence blue-shift in PCBM-doped perovskite films is observed. The effect of non-radiative recombination is obviously suppressed, and the photoluminescence lifetime is significantly prolonged by 3-fold after PCBM introduction. The roles of PCBM in trap states and hysteresis mechanism are also discussed. This research could provide experimental and theoretical supports for suppressing and eliminating the hysteresis phenomena in perovskite solar cells.