Effect of annealing on the optical characteristics of electrodeposited <002>-oriented CuO thin films

摘要

Formation of p-type CuO semiconductor films for the light absorption layer of photovoltaic cells was conducted by heteroepitaxial electrodeposition and post-annealing. The CuO films showed (002) orientation through the heteroepitaxial growth on the (111)-oriented Au substrate. The structural, optical, and electrochemical characterizations were carried out with X-ray diffraction (XRD), optical absorption spectra measurements, and photoelectrochemical response measurement. The bandgap energy changed from 1.05 to 1.22 eV depending on the annealing condition. It is speculated from the XRD that the CuO film with large grain size and small strain could be obtained at 300°C. The photoelectrochemical response has improved depending on the annealing condition. The annealed CuO films possess much better crystallinity and photoelectrochemical response than as-deposited CuO. The CuO film annealed at 300°C has the best quality.