Strong enhancement of emissions from nanostructured ZnO thin films grown by plasma-assisted molecular-beam epitaxy on nanopored Si(001) substrates

Nanostructured ZnO films were fabricated on nanopored Si(001) surfaces through reactive ion etching and plasma-assisted molecular-beam epitaxy techniques. Nanowall-like nanostructures were formed on the ZnO film surfaces depending on the thickness of the ZnO films. Significant enhancement of the photoluminescence intensity up to 15 fold was observed from the nanostructured ZnO films. We found that the emission properties of the film changed very sensitively with the nanostructure on the surface and the enhancement is closely related to the formations of nanostructures on the surface of the ZnO films, not at the interface between the films and the substrate. (c) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.