Fig. 1: Time evolution of the light-induced spatial variation in PL for a MA0.17FA0.83Pb(I0.5Br0.5)3 thin-film sample.
a PL mapping at 670 and 790 nm before local illumination (The dark area at the lower right corner is due to a marker). The scale bar is 40 μm. b PL mapping at 670 nm (top row) and 790 nm (bottom row) of the same area as in (a) after the center of the area being illuminated for different effective illumination times. The small dot indicates the pump beam size. c PL spectra at the initial state and after illumination over 30 min at the center. d, e Time-dependent PL spatial profiles taken along the white dashed lines from PL maps of 670 and 790 nm in (b), respectively. f The normalized time dependence of 670 nm PL intensity at the ring and center from (d), and 790 nm PL intensity at the center from (e). Symbols are data points, and lines are fitting curves
