Fig. 3

XPS spectra of a survey, b Sn 3d, c O 1 s, d Al 2p, and e Cl 2p peaks for Al-SnO₂ film deposited on the FTO substrate. f Normalized time-resolved PL decay curves of MAPbI₃ films deposited on SnO₂ (black line) and Al-SnO₂ (red line) coated substrates