Figure 2.

a) J–V curves of the PSCs without and with different MgO films based on FTO anode. b) The best performance of the PSCs with 0.045‐MgO HBL and without MgO HBL. Steady‐state efficiencies of the PSCs. Steady‐state efficiency of the SnO₂‐based PSCs c) with and d) without an MgO HBL at constant bias voltages of 0.82 and 0.80 V, respectively. e) A histogram of PCEs for 30 cells of the PSCs with and without MgO HBL measured under reverse voltage scanning. f) IPCE spectra of the PSCs with and without MgO HBL.