The effects of annealing temperature and angular velocity variation on microstructure and optical properties of barium titanate (BaTiO3) using chemical solution deposition method

Abstract

This study is aimed to find out the energy gap value of BaTiO3 thin film since this study has a purpose to reduce the energy gap so that it can be used for photovoltaic applications. The making of Barium Titanate (BaTiO3) thin film was carried out on the quartz substrate using the Chemical Solution Deposition (CSD) method with the technique of depositing spin coating. The making of BaTiO3 thin film was carried out using variation of angular velocity at 4000 rpm and 5000 rpm and variation of annealing temperature at 750°C, 800°C, 850°C. The samples in this study were annealed at 750°C, 800°C, 850°C with a holding time of 1 hour and an increase in temperature of 3°C/minute. The microstructure characterization of the samples was carried out using X-Ray Diffraction (XRD) equipment, and the thickness of the thin film characterization and grain size of samples using Scanning Electron Microscopy (SEM) equipment. The annealing temperature increase, the intensity becomes higher. As the annealing temperature increase, then the crystallinity, crystallite size and grain size of BaTiO3 thin film will get bigger. The annealing temperature increase is resulted the thickness and energy gap are smaller. The intensity value of the XRD remains decrease along with the angular velocity increase. The higher angular velocity causes the crystallinity and crystallite size of BaTiO3 thin film becomes higher. However, the angular velocity increase then the grain size will become smaller. The angular velocity higher, then the BaTiO3 thin film gets thinner. The angular velocity gets higher, then the smaller energy gap produced. The energy gap value was produced between 3.00 – 3.50 eV.