Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5402354 | Journal of Luminescence | 2010 | 5 Pages |
Abstract
We have studied systematically room-temperature photoluminescence (PL) properties of many nanostructured ZnO samples grown by chemical vapour deposition (CVD). Their PL spectra consist of two emissions peaked in the ultraviolet (UV) and green regions. The relative intensity of these emissions depends on the excitation energy density, size and morphology of ZnO nanostructures. Based on the excitation-density dependence of the integrated intensity ratio of UV-to-green emission, we could classify PL spectra of ZnO nanostructures into three groups characteristic of size and morphology. Our study also reveals that with increasing excitation density, the UV-peak position shifts slightly towards longer wavelengths while the green emission around 514-520Â nm is almost unchanged. This green-luminescence emission is dominant when the nanostructure sizes range from 20 to 200Â nm, which is related to a large surface-to-volume ratio.
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Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
The-Long Phan, S.C. Yu, R. Vincent, N.H. Dan, W.S. Shi,