Fig. 1. XRD and optical characterisation of CsxM compounds. (a) XRD spectra of perovskite upon addition of Cs investigating the series Csx(MA0.17FA0.83)(1–x)Pb(I0.83Br0.17)3, abbreviated as CsxM where M stands for “mixed perovskite”. CsxM with x = 0, 5, 10, 15%. (b) The corresponding (dashed lines) and photoluminescence (PL) spectra (solid lines).
