Fig. 6From: Lead-free perovskite solar cells using Sb and Bi-based A3B2X9 and A3BX6 crystals with normal and inverse cell structuresXRD patterns (a) and UV–vis absorption spectra (b) of Ag3BiI6, Ag3BiI3(SCN)3 and Cu3BiI6 casted on the glass substrates. The insets were the pictures of Ag3BiI6, Ag3BiI3(SCN)3 and Cu3BiI6 filmsBack to article page