Highly UV luminescent ZnO microtetrapod-on-nanowire hybrids

Abstract

The author reports the first all-ZnO microtetrapod-on-nanowire hybrids using the cost-effective Au nanoseed assisted open static atmospheric pressure vapor transport method. The unconventional ZnO flower analogue hybrid structure consists of center-tapered ZnO microtetrapods (typically 1-2 m in dimension) on ZnO 'backbone' nanowires (typically 20 nm in diameter). Three new Raman peaks, centered at 225, 275, 561 cm- 1, never seen before in ZnO nanocrystals, were first observed in the ZnO hybrids. The hybrids exhibit excellent luminescent properties with a single ultraviolet emission band centered at about 377 nm with an ultra-narrow full width at half maximum of ∼ 4 nm, which makes it a promising candidate for optoelectronic applications. A preliminary self-assembled synergic growth mechanism is proposed to understand the formation of the structurally stable morphology where the vapor-liquid-solid and vapor-solid mode work together. Our results could open up possibilities for making ZnO nanocrystals to a new level of more complex nanoarchitectures. © 2010 IOP Publishing Ltd.