Influence of annealing atmosphere and temperature on photoluminescence of Tb3+ or Eu3+-activated zinc silicate thin film phosphors via sol–gel method

Thin films of Zn2SiO4:Tb3+ or Eu3+ were deposited on silicon wafers by a sol–gel method. The films exhibited prominent green or red photoluminescence, due to the sharp and strong intra-4fn-shell electronic transitions. The thermogravimetric analysis curve shows a remarkable weight loss in the temperature range 50–400 °C, and a slow loss at higher temperature. The increases in fluorescence intensity and decay lifetimes of rare-earth ions sensitive to microstructure and chemical components are attributed to OH removal, nano-crystallite formation and the increased surface roughness by treatment of temperature. Strongly enhanced photoluminescence was observed in samples annealed at 950 °C in a nitrogen atmosphere.