Extended Data Fig. 3: PL mapping of the buried interfaces.
From: High-efficiency and thermally stable FACsPbI3 perovskite photovoltaics
a, b, PL images (a) and histograms of pristine and IPA α-FA0.94Cs0.06PbI3 films (b) before and after ageing in ambient for one month. The PL images were taken from the buried interface sides. As shown, the pristine α-FA0.94Cs0.06PbI3 film exhibits significantly reduced PL intensity, and nonuniform PL emission across different areas. The phenomenon indicates that increased defect density at the buried interface arises after ageing. In contrast, no notable PL quenching and inhomogeneity were observed in the aged IPA α-FA0.94Cs0.06PbI3 films. The results are consistent with SEM and GIXRD measurements in Supplementary Note 8.
