Growth Study Of ZnO Films On Si Substrate And Degradation Of GaN/Si White LED

In this dissertation, the research on the growth of ZnO thin films on Ni/Si(111)template by home-made MOCVD was carried out, from which some encouraging results are following as:1. ZnO films were grown on Si(111) substrate by AP-MOCVD system. In order to eliminate the effect on the quality of ZnO from the mismatch and protect the Si substrate from oxidation, a 10A Ni buffer layer was put forward to deposit on the Si substrate by high vacuum electron beam evaporation system firstly. Then, the Ni/Si(111) template was transferred to grow ZnO epilayer in AP-MOCVD system.2. Both ZnO films deposited with and without Ni metal layer on Si(111) substrate exhibited (002) peaks for wurtzite structure ZnO, indicative of preferential orientation with the c-axis perpendicular to the substrate. The full-width at half-maximum(FWHM) of ZnO (002) for the direct Si(111) substrate grown film was 0.35° while the Ni/ Si(111) substrate grown film had a narrower FWHM of 0.21°. Meantime, (002) peak of both films shifts slighty toward the higher diffraction angle(with Ni 2θ=34.5°, without Ni 2θ=34.7°) compared to the normal value of the bulk ZnO material(2θ=34.42°). It is the contribution of the inhomogeneous strain in the layer for the large lattice mismatch and the large thermal mismatch between the ZnO epilayer and Si substrate. The film with Ni layer has a relatively less shift than the films without Ni layer. This suggests that the film grown with Ni buffer layer exhibits higher structural quality and eliminate the mismatch between the epilayer and substrate.3. UV emission was observed in both ZnO films with and without Ni metal layer in room temperature photoluminescence(RT-PL) spectrum. The ratio of the intensity of UV emission to that of deep level emission was 20:1 and 8.5:1 , this indicated the ZnO film grown on Ni/Si(111)template has less defects.4. Compared with using DMZn as reacting resource to grow ZnO film, the film using DEZn as reacting resource to grow has a strong NBE peak and without...