Sol–gel derived zinc silicate phosphor films for full-color display applications Original Research Article

Zn2SiO4 phosphor thin films doped with rare-earth ions including Tb3+, Eu3+ and Ce3+ have been prepared using a wet chemistry sol–gel process. Optical properties and microstructure of these films were reported and discussed. Thin films containing Tb3+ and Eu3+ have shown bright green- and red-phosphorescent colors upon exposure to the UV source, due to the sharp and strong intra-4fn-shell electronic transitions of Tb3+ (5D4→7F5) and Eu3+ (5D0→7F2), respectively. Meanwhile, the photoluminescence of Zn2SiO4/Ce3+ thin film mainly shows a broad band in the visible region peaked at around 489 nm, which results from 5d→4f electron transition of Ce3+. The thermogravimetric analysis curve shows a remarkable weight loss in the temperature range of 50–450 °C, and slow loss continuing at higher temperature above 800 °C. The increase in fluorescence and decay lifetimes of rare-earth ions sensitive to films microstructure and chemical components corresponding to this weight loss are attributed to nanometer polycrystallites formation and OH removal by treatment of temperature.