Photoluminescence of ZnO−SiO2 nanocomposite and its excitation wavelength dependence

The influence of SiO2 capping and excitation wavelength on photoluminescence (PL) of ZnO nanoparticles was studied. XRD and FE-SEM analysis of the samples showed that the particles size reduced from 54 nm to 10 nm with SiO2 capping. The PL spectra of ZnO−SiO2 nanocomposites were acquired with 320 and 353 nm excitation wavelengths. A sharp UV emission positioned at 398 nm was obtained with 353 nm excitation wavelength and its intensity is five times greater than the one achieved with 320 nm excitation wavelength. It was also found that with SiO2 capping, intensities of the 418 nm and 587 nm emission peaks increased.