Visible photoluminescence of ZnO nanoparticles dispersed in highly transparent MgF2 thin-films via sol-gel process

ZnO/MgF2 nanocomposite thin films, where ZnO nanoparticles were dispersed in an MgF2 matrix, were prepared by a sol-gel method using metal acetates, isopropanol, trifluoroacetic acid, monoethanolamine and water as starting materials. The particle size of ZnO was approximately 6.2 nm, showing quantum size effects in the absorption edge measurement. Green photoluminescent (PL) emission from the films was observed at room temperature. The emission intensity was found to be greatly dependent on heat-treatment temperature and time. By optimizing the heating conditions, the film with high transparency and high PL intensity was obtained. Influence of the heating conditions on the formation of the ZnO nanoparticles and the green emission was discussed. (C) 2001 Elsevier Science B.V. All rights reserved.