Effect of Annealing on Copper Oxide Thin Films and Its Application in Solar Cells

Abstract

Cupric Oxide (CuO) thin films were prepared by chemical spray pyrolysis (CSP) method at 400°C on glass and p-type Si substrate and then the films were annealed at 500°C and 600°C. The structural, optical and electrical properties of the thin films are measured. The analysis of X-ray diffraction (XRD) has confirmed amorphous phase mixed with polycrystalline features in the form of monoclinic structure. However, the polycrystalline CuO disappeared and changed to crystallite phase with increasing of annealing temperature. The values of bandgap energy (Eg) of the films were calculated using the absorbance data recorded by a spectrophotometer (UV-VIS). The calculated Eg using Tauc plot was about 2.45 eV which increased with increasing of annealing temperature. CuO thin films with high conductivity have been used to fabricate a hetrojunction solar cell of CuO/p-Si at 600°C which give Rs = 111Ω, Rsh = 7kΩ and a conversion efficiency of 1.24×10-4%.