Surface, structural, and optical property variations of ZnO nanocrystals formed on Si substrates due to thermal treatment

Abstract

ZnO nanocrystals were formed on Si substrates using spin coating and thermal annealing. X-ray diffraction patterns showed that the intensity of the ZnO (0002) peak corresponding to the ZnO [0001] nanocrystals increased with an increase in annealing temperature up to 700 degrees C, indicative of the improvement of the crystallinity of the ZnO nanocrystals. The photoluminescence spectra at 13 K for ZnO nanocrystals formed on the Si substrates showed that the strong exciton peak related to the near-band-edge emission was shifted to a lower energy with increasing annealing temperature resulting from the increase in the size of the ZnO nanocrystals.