Figure 1: Impact of MABr treatment on the structural and electro-optical properties of MAPbI₃ thin film.

Top view of the SEM images of (a) MAPbI₃ and (b) MABr-treated MAPbI₃ films. Scale bars, 1 μm. Comparison of (c) UV-vis absorption spectra and (d) X-ray diffraction patterns of MAPbI₃ films with and without MABr treatment.