Structure and optical properties of the SiC/ZnO five-layer multi-layer on Si (III) substrate with a SiC buffer layer

A SiC/ZnO five-layer multi-layer on Si(111) substrate with a SiC buffer layer was fabricated using the radio frequency -magnetron sputtering technique. The as-deposited films were annealed in the temperature range 600-1000 °C under nitrogen ambient. With the increase in annealing temperature (Ta), especially from the Ta approximately 800 °C, the quality of the SiC buffer layer is improved, resulting in the enhancement of the crystal quality of ZnO. With the further increase in Ta up to 1000 °C, the crystal quality of ZnO becomes worse because the ZnO layers and SiC layers penetrate each other greatly and the interfaces between ZnO and SiC are very impacted and complicated, which can be demonstrated by the emergence of the new peaks (869, 890 and 927 cm ^-1) in the Fourier transform infrared spectroscopy spectra. We have also discussed the photoluminescence properties of the sample in great detail. The optical properties of the sample are strongly dependent on the condition of the SiC buffer layer. Furthermore, with the increase in Ta, the near band edge emission has a tendency of redshift due to the enhancement of the penetration or interaction between the ZnO layers and SiC layers resulting in the band structure deformation or lattice deformation. The origin of the 416 nm peak is associated with the interface traps existing in the depletion regions between the ZnO-ZnO grain boundaries.