Growth and Characterization of ZnO Nano-Rods on Si Substrate by Pulsed Laser Ablation

Zinc oxide (ZnO) nanorods were fabricated directly on silicon substrate with diameters in the range of 70-350 nm and up to 15 νm long using pulsed-laser deposition at a relatively low processing temperature (450°C) without any catalytic template. The influences of substrate temperatures and the oxygen pressures on the formation of ZnO nanorods were investigated. The Raman scattering studies and scanning electron microscopy results indicated that the ZnO nanorods were well aligned along c-axis and isolated from each other. The additional Raman modes at ∼ 477 cm−1 and 574 cm−1 were observed in the c-axis oriented ZnO nanorods which attributed to the activation of the upper and lower surface phonon modes respectively.