Investigation of the Structural, Morphological, and Optical Properties of ZnBr2-Added MAPbI3 Perovskite Thin Films

Abstract

Methylammonium lead iodide (MAPbI3) perovskite thin films, which were pure and ZnBr2-added at different rates (1, 3, and 5 wt%), were deposited on fluorine-doped tin oxide/titanium dioxide (FTO/TiO2) substrates by the spin coating method. X-ray diffraction (XRD) analysis showed that the peak at 14° was the main peak for all thin films. A shift was observed with the addition of ZnBr2 at the main peak position. As the ZnBr2 addition rate increased, PbI2 peaks occurred at 12.5°. It was seen in the scanning electron microscope (SEM) surface image that the grain sizes were larger than the others on the MAPbI3 perovskite thin film with 5 wt% ZnBr2 added. For MAPbI3 perovskite thin films with 5 wt% ZnBr2 added, the absorbance value in the visible region (from 390 to 780 nm) was higher than the others. It was observed that the band gap value (Eg) of MAPbI3 perovskite thin films can be adjusted by adding ZnBr2.