Effect of annealing temperature on the microstructural and electrical properties of epitaxial Ga-doped ZnO film deposited on c-sapphire substrate

4 wt. % Ga-doped ZnO (GZO) film has been prepared on c (0001)-sapphire (Al2O3) substrate by Pulse Laser Deposition method. The effect of annealing temperature on the microstructural and electrical properties of the GZO thin film was investigated. X-ray diffraction and High-Resolution Transmission electron microscopy (HR-TEM) studies showed that the electrical and defects properties of GZO thin film were greatly influenced by annealing temperature. The crystallinity and electrical properties of the film can be improved by annealing at 800 A degrees C. However, at a too high annealing temperature of 1,000 A degrees C, the newly processing defects such as extended dislocations and a new nanoscale stacking fault were formed. Consequently, the crystallinity and electrical properties of the film annealed at 1,000 A degrees C were degraded. The study was useful to acquire optimal annealing conditions to improve the properties of film.