Zinc oxide and cupric oxide based thin films for solar cell applications

Abstract

Zinc oxide (ZnO), cupric oxide (CuO) and ZnO/CuO bilayer thin films were prepared on glass substrates using spin coating process followed by annealing at 450 °C for 1 hr in ambient environment. Their structural and optical properties were studied in details using XRD and UV–VIS–NIR spectrometer. XRD patterns depict that all the films were polycrystalline in nature with average crystallite size in the range of 13–15 nm. From optical analysis, it has been shown that the ZnO thin film displayed a large optical band gap (3.22 eV) and high optical transmittance property (∼80%) in the visible range. While ZnO/CuO thin films exhibit large absorbance property unlike ZnO, due to the narrow band gap semiconductor of CuO (1.90 eV) and considered to be utilized for solar cell applications.