Ultrathin aligned ZnO nanorod arrays grown by a novel diffusive pulsed laser deposition method

ZnO nanorod (NR) arrays were grown on Si at elevated temperatures using a two-stage diffusive pulsed laser deposition (DPLD) technique. A thin (similar to 50 nm) seed-layer was first formed by pulsed laser ablation of ZnO in O(2). The sample was then turned to face away from the propagation direction of the ablation plume, and the ablation process continued. A dense array of ultrathin NRs was seen to grow from the seed-layer. These NRs are thinner (d similar to 10 nm), and display a similar to 20-times higher aspect ratio than those grown by traditional PLD under otherwise identical process conditions. (C) 2009 Elsevier B. V. All rights reserved.