The microstructure and cathodoluminescence characteristics of sputtered Zn2SiO4:Ti phosphor thin films

The structural characteristics and cathodoluminescent properties of Ti doped Zn2SiO4 films deposited by radio-frequency sputtering are studied. The as-deposited Zn2SiO4:Ti film is amorphous and it transforms to α-Zn2SiO4 phase after annealing at 900 °C or higher temperature. For the 1000 °C-annealed film, transmission electron microscopy reveals homogeneous α-Zn2SiO4 crystals with grain size about 330 nm. Also, the absorption edge at 225 nm corresponds well to the band gap of α-Zn2SiO4. According to the cathodoluminescent measurement, blue-light emission (at 403 nm) is observed only when the Zn2SiO4:Ti film becomes crystallized after high-temperature annealing. The emission intensity of Zn2SiO4:Ti films increases with increasing Ti concentration, and it can be significantly intensified to 100 times by doping 1 mol% of Ti into the Zn2SiO4 films.