Green photoluminescence from highly oriented ZnO thin film forphotovoltaic application

摘要

We report here the fabrication of ZnO nanoparticles embedded on glass substrate by sol-gel and spincoating technique. Transmission electron microscope images revealed that the thin film is composed ofZnO nanoparticles. X-ray diffraction data confirms that the fabricated ZnO nanoparticles have hexagonalunit cell structure. The ZnO nanocrystals of the thin film are oriented along the c-axis of the hexagonalunit cell. UV-vis absorption spectroscopy shows that the absorption occurring at 373 nm in the ZnOthin film. The band gap was calculated from the absorption data and found to be 3.76 eV. This band gapenhancement occurs due to size effect in the nanoscale regime. Room temperature photoluminescencespectrum shows strong green emission at 530 nm owing to the singly ionized oxygen vacancy. This greenemission was further investigated by annealing the thin film at different temperature. This singular greenemission will be very useful in optoelectronic and nanophotonic devices.