Investigation on the Crystallinity and Optoelectronic Properties of Thin Films of Zno/Mapbx3heterojunctionsynthesized via the Spin-Coating Method

Abstract

In this paper, thin layers of ZnO were deposited onto fluorine-doped tin oxide (FTO) substrates. Subsequently, different layers of perovskite (MAPbX3, X = I, Br, Cl) were spin-coated onto these ZnO layers. The resulting layers were characterized using X-ray diffraction (XRD), UV-Visible spectroscopy, and scanning electron microscopy (SEM). Special attention was given to the surface topography, the crystallinityand optoelectronic properties.XRD analysis of all the thin layers showed two diffraction peaks for the ZnO/MAPbX3 heterojunction corresponding to the crystallographic planes (100) and (200). The ZnO/MAPbBr3 peaks were more intense than the peaks from the ZnO/MAPbI3 and ZnO/MAPbCl3 samples. SEM images showed the crystalline nature of the produced thin layers. The grain size of the ZnO/MAPbBr3 sample was approximately 747.00 nm, while those of the ZnO/MAPbI3 and ZnO/MAPbCl3 samples were 412.00 nm and 330.55 nm, respectively. UV-visible characterization demonstrated that the iodine-based sample had the highest solar radiation absorption and had the smallest bandgap, with Eg = 1.95 eV.