Preparation and Characterization of Nanosized ZnGa[sub 2]O[sub 4] Phosphors

Nanosized zinc gallate phosphors were prepared via the citric gel route and their luminous properties were characterized by photoluminescence in this study. From the results of X-ray diffraction studies, it was found that a spinel phase of ZnGa 2 O 4 formed after the dry gel had been heat-treated at 470°C for 1 h and well-crystallized spinel phosphors with an average particle size of 35 nm were obtained after the dry gel had been heat-treated at 700°C for 5 h. The photoluminescence studies manifested that the shapes and the wavelengths of maximum intensity of the absorption and emission spectra were independent of the heat-treatment temperature in the range between 600 and 1000°C. Instead of the normally observed bell-shaped spectrum, peak-shaped emission spectra were observed when these nanosized phosphors were excited with UV light of wavelength of 254 nm. The peak-shaped emissions with maximum intensity at a wavelength of 470 nm correspond to the self-activated luminescence of ZnGa 2 O 4 .