Title : Structural and optical characterization of CZTS Films on kapton deposited via SILAR for photovoltaic applications
Abstract:
This study presents the structural, chemical, and optical characterization of CZTS films deposited on Kapton substrates using the Successive Ionic Layer Adsorption and Reaction (SILAR) method, with deposition cycles ranging from 40 to 80. X-ray diffraction (XRD) revealed enhanced crystallinity and phase purity, particularly in samples subjected to 70 deposition cycles and post-annealing. Pole figure analyses showed improved crystalline orientation and reduced anisotropy in these samples. Surface morphology improvements, including grain uniformity, were observed through field emission scanning electron microscopy (F-SEM). Chemical consistency across the films was confirmed through SIMS and EDS techniques, while XPS analysis indicated a mix of CZTS and oxide phases. Notably, annealing at 450°C refined the film composition and reduced secondary phases like ZnO, SnO2, and CuO. The bandgap was reduced from 1.5 eV to 1.36 eV post-annealing, as explained by Density Functional Theory (DFT) calculations. Valence band analysis via XPS revealed p-type conductivity. These findings underscore the potential of the SILAR method as a low-cost, non-vacuum technique for producing high-quality CZTS films.