Investigation on the optical transmission in UV range of sol-gel spin coated zinc oxide nanofilms deposited on glass

Physical properties of semiconductor thin films change when reducing their thicknesses from micro- to nanoscales. Indeed, zinc oxide (ZnO) microfilms absorb ultraviolet (UV) light; however, the optical transmission of the ZnO nanofilms shows double transmission edges in the same range of wavelengths. In the present work, we deposited ZnO nanofilms on glass substrates by sol–gel spin coating method. We carried out grazing incidence X-ray diffraction (GIXRD), where results showed that elaborated ZnO nanofilms have wurtzite structure, with dominance along (100), (002) and (101). A bruker profilometer gives a thickness about 119 nm. The photoluminescence at room temperature of films carried out with Horiba iHR 550 shows a strong luminescence in visible range. The ZnO nanofilms showed high optical transmission in the UV and the visible ranges with a drop of about 50% in the wavelengths range of 300-400 nm. The high optical transmission observed in the UV range was explained by photoluminescence.