Abstract
ZnO nanorod arrays have attracted considerable attention as a candidate for fabricating gas sensors, dye-sensitized solar cells, and light emitting diodes (LEDs) in the last few years. Controlling the growth of ZnO nanorods is of importance in terms of reproducibility for the practical applications. In this paper, we have grown ZnO nanorod arrays on Si (100) substrates by two-step growth. First, ZnO powder dispersed on a Si substrate is thermally annealed in air. Next, after annealing for nucleation, ZnO was deposited on the seed layer for one hour duration. As a result, ZnO nanorod arrays were observed by field emission scanning electron microscopy (FE-SEM). The diameter of the thinnest ZnO nanorods was 30 nm, and the length ranged from 500 nm to 10,000 nm. Furthermore, we investigated their surface enhanced Raman scattering (SERS) properties by using a structure known as a nanoshell, and coating gold (Au) around ZnO nanorods.