Effect of GaN/Si(111) template on structural and optical properties of ZnO nanostructures

Abstract

Zinc oxide (ZnO) nanostructures are grown on p- and n-GaN/Si(111) by aqueous method in this paper. The structural and optical properties of the nanostructures are characterised by X-ray diffraction, scanning electron microscopy (SEM), atomic force microscopy, micro-Raman and photoluminescence. The results show the distinct appearance of ZnO nanostructures grown on different GaN substrates. The ZnO nanorod array with a hexagonal wurtzite structure is grown on the n-GaN/Si substrate, whereas the film-like structure is shown on p-GaN/Si. The morphology difference is due to the density of threading dislocations in the different doped GaN layers that can affect the ZnO nanorod density. Meanwhile, the ZnO nanostructures grown on n-GaN/Si show superior optical property with lower tensile stress compared with those on p-GaN/Si. The results will provide novel opportunities for the fabrication of hybrid ZnO/GaN optoelectronic devices.

Keywords:

• ZnO nanostructures
• Aqueous solutions
• GaN template

This work was supported by the National Natural Science Foundation of China (grant no. 51102036) and the Fundamental Research Funds for the Central Universities (grant no. DC 10030107).