Low-temperature synthesized ZnO nanoneedles: XPS and PL analysis

Evolution of morphology change was investigated for ZnO nanoneedle array grown by low-temperature MOCVD. Well-aligned ZnO nanoneedle array was deposited on the ZnO buffer-film/Si substrate at temperatures below 500 degrees C. A rod-shaped ZnO nanowire in the initial growth stage changed into needle-shaped as the deposition proceeds. ZnO nanoneedle array deposited on the annealed buffer-film showed better alignment compared to that deposited on the as-grown film. XPS analysis showed that Zn 2p peak has a single binding energy state of a stoichiometric Zn-O bond while O 1s peak has three different chemical binding states. Highly crystalline ZnO nanoneedle array showed a strong bandedge emission at 380 nm in photoluminescence measurements.X1113sciescopu