“…Urbach energies from CH 3 NH 3 Pb(I 1−x Br x ) 3 perovskites in this study are shown as red squares, and those from literature data are shown as blue triangles. 11,14 Also shown are a range of technologically important semiconductors (black dots): CZTSSe (Se-rich Cu 2 ZnSn(S,Se) 4 ),20 Si, 10 CIGS (Cu(In,Ga)Se 2 ),19 InP,29 GaAs, 30 CdTe,31 CZTS (S-rich Cu 2 ZnSnS 4 ),20 CGS (CuGaSe 2 ), 32 a-Si, 33 a-SiC:H,34 Al 0.05 In 0.95 N,35 and In x Ga 1−x N (In-rich, graded In profile).36…”