The influence of ultraviolet exposure and humidity on the photoluminescence spectra of zinc oxide

The structure and electrical and luminescent properties of arrays of zinc-oxide nanorods grown by the hydrothermal method are studied. It was found that the exposure of samples to ultraviolet light or the presence of water vapor in a gaseous atmosphere significantly change the photoluminescence spectra. The exposure of samples leads to a substantial increase in intrinsic photoluminescence and a decrease in impurity photoluminescence. The presence of water vapor leads to the opposite effect. It is shown that the observed effects are caused by the change in the surface-band bending and the thickness of the depletion region.