Pure UV photoluminescence from ZnO thin film by thermal retardation and using an amorphous SiO2 buffer layer

► ZnO/SiO2 thin films on Si substrates were fabricated by E-beam evaporation. ► The SiO2 buffer layer is amorphous. ► PL spectroscopy showed that UV luminescence at only 374 nm is observed for all samples. ► The optical quality of the ZnO film has been improved by thermal retardation and by using an amorphous SiO2 buffer layer.