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.