Effect of ultraviolet-illumination and sample ambient on photoluminescence from zinc oxide nanocrystals

We report an effect of measurement conditions on the photoluminescence intensities of zinc oxide nanoparticles. It was found that in vacuum under UV illumination intensity of near-band edge emission increases while defect related emission intensity decreases. We attribute this effect to a decrease in the depletion region width due to oxygen desorption on the surface of the zinc oxide nanocrystals.