Strong localization effect in temperature dependence of violet-blue emission from ZnO nanoshells

Violet-blue photoluminescence of Zn/ZnO core/shell nanoparticles, induced by laser ablation in liquid, was observed. The emission band shows an abnormal red first and then blueshift with temperature increasing from 8 to 300 K and abnormal narrowing at the temperature range from 30 to 130 K. Such temperature-dependent behaviors can be well described by localization model on interstitial zinc defect on both peak energy and peak width evolutions, reflecting the strong localization effect from the special microstructure. This work will be beneficial to understanding of the physical origins of the violet-blue emission in nanostructured ZnO, and extending its optical and electronic applications.