The effect of calcination temperature on the photoluminescence from sol–gel derived amorphous ZnO/silica composites

Amorphous ZnO/silica composites are prepared by an in situ sol–gel technique, and the effect of calcination temperature on photoluminescence (PL) is studied. XPS spectra reveal that majority of Zn2+ locate at the interfaces between ZnO particles and silica matrix. PL emission spectra consist of near-UV (365 nm), violet (404 nm), blue (443 nm) and green (517 nm) bands. The composite calcined at 700 °C shows the strongest PL emission. Considering that calcination temperature presents a similar effect on the intensities of the violet and the UV emission, the violet emission originates from the amorphous ZnO phase, not from the interfaces between ZnO particles and silica matrix.