Effect of homo-buffer layers on the optical properties of ZnO thin films grown by pulsed laser deposition on Si (100)

The influence of homo-buffer layers deposited at high-temperature (HT) or low-temperature (LT) and post-annealing process on the structure and photoluminescence properties of ZnO films grown by pulsed laser deposition on Si (100) was studied by X-ray diffraction (XRD), atomic force microscope (AFM) and photoluminescence spectrum (PL). It is found that the optical property of the films can be improved greatly because the stress between the films and the substrates could be reduced by using buffer layers. By using LT buffer layer, high-quality ZnO films with only one strong ultraviolet emission (UV) can be obtained, but the post-annealing process in air will make the optical property of the film deteriorate.