Optical Characterization and Growth Mechanism of Combination of Zinc Oxide Nanowires and Nanorods at Various Substrate Temperatures

摘要

We report on the growth of ZnO nanostructures on n-type silicon substrate using pulsed laser deposition technique at substrate temperature ranging from room temperature to 600℃ for one hour.We observe both rod- and wire-like structures with different dimensions at room temperature, 150℃, and 450℃ substrate temperatures and only wire-like structures at 300℃ and 600℃. These combinations of different shapes have been attributed to the initial growth of nanostructures (nucleation sites) on the surface obtained during the deposition for 20 minutes.The narrowing in the full-width-half-maximum of the peak corresponding to (002) plane of XRD is looked upon as another possible explanation. The blue shift of the peak at 396nm observed in the photoluminescence is due to the quantum confinement. The intensity of E_2(high) mode at 437 cm~(-1) increases indicating improvement in crystallinity with the substrate temperature.