Fig. 1: Morphological disorder in mixed-halide perovskite thin films.
From: Local halide heterogeneity drives surface wrinkling in mixed-halide wide-bandgap perovskites
a Bandgap from ultraviolet-visible-near infrared (UV-vis-NIR) spectroscopy as a function of (FA1−xMAx)Pb(I1−yBry)3 perovskite composition. Gray areas represent compositions that were not considered due to phase instabilities in ambient measurement environments. Shaded regions mark perovskite compositions compatible for top-cells in tandem and triple-junction solar cells. b–g Surface scanning electron microscopy (SEM) images of perovskite thin films for different compositions {x/y}. b {x/y} = 0.25|0.40. c {x/y} = 0.50|0.40. d {x/y} = 0.75⁞0.40. e {x/y} = 0.25¦0.60. f {x/y} = 0.50⁞0.60. g {x/y} = 0.75⁞0.60. h, i Three-dimensional atomic force microscopy (AFM) height profiles of perovskite thin films. h {x/y} = 0.25|0.40. i {x/y} = 0.50⁞0.60. j–o Line cuts from AFM height profiles and average maximum profile height (Rp) for perovskite thin films for different compositions {x/y}. j {x/y} = 0.25|0.40. k {x/y} = 0.50|0.40. l {x/y} = 0.75⁞0.40. m {x/y} = 0.25¦0.60. n {x/y} = 0.50⁞0.60. o {x/y} = 0.75⁞0.60.
