Fabrication of CUO!CU2O Heterojunction and Its Local Structural Characterization

Abstract

Cuprous oxide (Cu20) thin films on Ti substrate were potentiostatically electrodeposited at -200 mV in an acetate bath. For the growth of p-type cupric oxide (CuO) thin films , CU20 thin film s were annealed at 500 oC (for 30 min in air. In order to fabricate CuO/Cu20 hetorojunction, thin film of Cu20 was potentiostatically electrodeposited on Ti/CuO electrode . Deposits were characterized by using X-ray diffraction (XRD) and scanning electron micrographs (SEM). Results revealed that well covered n-tvpe polycrystall ine Cu20 thin film can be electrodeposied on Ti/CuO electrode at -550 mV VS the SCE in an acetate bath. The CuO/Cu20 heterojunction gave the open circuit voltage (Voc)of 210 mV and short circuit current (Jsc) of 310 uA/cm2. Layer by layer structural properties of the electrodeposited Ti/CuO/Cu20 thin film heterojunction have been studied by means of the XRD and the X-ray absorption spectra (XAS) with different grazing angles of the incident Xray beam. Results reveal that Cu20 and CuO are high quality semiconducting thin films but amorphous structure is formed between CuO and Cu20 while Cu20 deposition on CuO. It can be expected that amorphous structure formed in the middle of the CuO/Cu20 heterojunction attributes better lattice matching between CuO and Cu20 interface .