Effects of homo-buffer layer and annealing treatment on optical property of ZnO thin film

ZnO thin films with ZnO homo-buffer layer were grown on Si (111) substrates by PLD. The buffer layers, about 15 nm thick, were deposited at 300°C,400°C and 500°C, respectively, under a base pressure of 1×10^-3 Pa. The main ZnO layers (about 400nm thick) were grown at 650 °C for 90 min in an oxygen ambience of 60 Pa. All the films were annealed at 500 °C for 20 min in an oxygen ambience of 105 Pa. PL spectra show that the PL peak intensity of the ZnO film with a homo-buffer layer gown at 300°C was strongest after annealing. It means that the combination of growing homo-buffer layer at a suitable low temperature and employing appropriate post-anneal treatment is an effective method to improve the optical feature of ZnO thin film grown by PLD.