RF sputtering enhanced the morphology and photoluminescence of multi-oriented ZnO nanostructure produced by chemical vapor deposition

[Display omitted] ► A ZnO nanostructure was synthesized using the CVD and RF techniques. ► High-quality ZnO nanorods were obtained. ► The nanorods grow at a random angle on the substrate surface. ► The RF sputter-coating step enhanced the structural quality of the ZnO film. Pure hexagonal wurtzite ZnO nanostructure was successfully synthesized by chemical vapor deposition (CVD) and RF-magnetron sputtering without using any catalysts. In the two-step process, high-quality multi-oriented ZnO nanorods were obtained. Multi-oriented spear-like ZnO rods were pre-deposited on the SiO2/Si(100) substrate by CVD at 700°C followed by RF sputtering of the ZnO nanostructure. The synthesized ZnO nanostructures were characterized by X-ray diffraction, field emission scanning electron microscopy, and photoluminescence (PL). The results show that the RF sputtering of the ZnO nanostructure, which was coated with a ZnO film produced by CVD, might have promoted the uniformity and crystalline quality of the multi-oriented spear-like ZnO film. The PL spectra revealed a sharp and dominant peak located at approximately 382nm with a UV-to-visible PL intensity ratio (IUV/IVS) of 42 for the sample that was produced by the two-step process. The growth mechanism of the multi-oriented spear-like ZnO nanorods was investigated.