Ultrasonik Sprey Piroliz Yöntemi ile Üretilen Güneş Soğurucu CH3NH3PbI3-xClx Perovskit Yapısının Optik, Morfolojik ve Yapısal Özelliklerinin İncelenmesi

In this study, CH3NH3PbI3-xClx perovskite thin films were deposited on glass substrates by the ultrasonic spray pyrolysis method. The effect of substrate temperature on the structural, morphological and optical properties of perovskite films was investigated using an X-ray diffraction (XRD) device, scanning electron microscope (SEM), atomic force microscope (AFM), and Uv-Vis spectrophotometer. When the X-ray diffraction spectra were observed, it was determined that all films were formed in the tetragonal perovskite lattice structure, but it was observed that different undesirable crystal structures were formed in thin films with 75 °C and 100 °C substrate temperatures. Although no post-annealing process was applied to the films, it was determined that the films coated at 125 ° C substrate temperature were in the form of pure perovskite crystals, which are exactly compatible with the literature. The crystal sizes of thin films were determined by using XRD spectrum data and Debye-Scherrer formula. The highest crystal size was obtained as 743 A for the thin film deposited at a substrate temperature of 125 °C. When the SEM images were examined, it was determined that the film surfaces were homogeneously coated at only 125 °C substrate temperature and that there were no voids between the crystal particles. The surface roughness of the films was examined by atomic force microscopy system, and the smoothest surface roughness was obtained in the thin film deposited at 125 °C substrate temperature with 41.32 nm. Optical absorption studies were carried out by using a Uv-Vis spectrophotometer operated at room temperature. It was observed that as the substrate temperature applied while coating the films increased, the forbidden bandgap of the film increased from 1.20 eV to 1.56 eV, which is also compatible with the theoretical analysis.