Studies on the Properties of Pulsed Laser Deposited ZnO-Y2O3 (YZO) Thin Films for Application as TCO Layer in Solar Cells

ZnO is naturally an n-type semiconductor with the wide direct band gap of 3.37 eV and the material is naturally abundant in the earth’s crust. Owing to its low toxicity ZnO finds application in devices like solar cells, flat panel displays and thin film transistors. It is a prominent wide bandgap material with appreciable transparency which is widely utilized in transparent conducting oxide layer applications. However, metal doping on ZnO reports was extensively investigated for tuning the electrical properties. This article is focused on pulsed laser deposition of ZnO-Y2O3 (YZO) thin films with various concentrations of Y2O3 (0-5%) as a dopant in ZnO. X-ray diffraction spectrum of the YZO thin films exhibits the presence of hexagonal wurtzite structure with a preferential orientation along the (002) plane. Morphology aspects of the film abide with XRD results which shows a uniform distribution till 2 wt% and resulted in grain growth with increasing wt% of Y2O3. The influence of Y2O3 concentration on the optical transmittance of ZnO is investigated by UV- Vis spectroscopy. The electrical resistivity of the deposited films is in the order 10-4 which was on par with the earlier reports suitable for TCO applications.