ZnGa2O4:Dy3+ phosphor thin films were deposited on quartz substrates by radio frequency (rf) magnetron sputtering and the effect of substrate temperature on its structural and luminescent properties was investigated. Polycrystalline film could be deposited even at room temperature. The crystalline behavior, Zn/Ga ratio, and surface morphology of the films were found to be highly sensitive to substrate temperature. Under UV illumination, the as-deposited films at and above 300 degrees C gave white luminescence even without any postdeposition treatments. The photoluminescent (PL) emission can be attributed to the combined effect of multicolor emissions from the single luminescence center Dy3+ via host-sensitization. Maximum PL emission intensity was observed for the film deposited at 600 degrees C, and the CIE chromaticity coordinates of the emission were determined to be (x,y)=(0.34, 0.31). (c) 2007 The Electrochemical Society.