Effects of nitrogen pressure during pulsed laser deposition on morphology and optical properties of N-doped ZnO nanostructures

Thin films, nanorod and nanopore arrays of N-doped ZnO (ZnO/N) have been prepared on quartz substrates, respectively, under different nitrogen pressures by pulsed laser deposition technique. The chemical bonds and nitrogen contents in the composition of ZnO/N nanostructures are characterized with X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy respectively, which confirm the implantation of nitrogen in ZnO. The optical properties of those ZnO/N nanostructures are studied with UV-visible transmission and photoluminescence measurements. The transparency of those ZnO/N nanostructures in visible range decreases when morphology varies from films, nanorods to nanopores. The photoluminescence of ZnO/N nanostructures at room temperature and low temperature of 4.6 K reveals a blue-shift of photoluminescence peaks when the nitrogen pressure changes from 26.7 to 80.0 Pa. Interestingly, we also observe that the dominated photoluminescence peaks of ZnO/N nanostructures at temperature of 4.6 K are modulated with the nitrogen content in ZnO/N nanostructures.