Effect of alkaline-doping on photoelectrochemical activity of electrodeposited cuprous oxide films. (19th July 2018)

• Record Type: Journal Article
• Authors: Chen, Ying-Chu; Hsiao, Zhi-Qian; Hsu, Yu-Kuei
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 29(2018)
• Page Start: 13032
• Page End: 13038
• Publication Date: 2018-07-19
• Subjects: Cuprous oxide -- Alkaline ion -- Photoelectrochemical -- Electrochemical deposition; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2018.05.090
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: P-type Cu2 O films with alkaline ions (Li +, Na + and K + ) of unintentional dopants on indium tin oxide coated glass substrate are successfully fabricated via a simple electrodeposition method for photoelectrochemical (PEC) hydrogen generation. The SEM and XRD analysis show the as-grown films with the pyramid-like morphology and cubic structure, and the composition of alkaline-doped Cu2 O films are examined using XPS spectroscopy to demonstrate the substitution of alkaline ions in the Cu2 O lattice. The optical analyses, including the absorbance and low-temperature photoluminescence spectra, confirm a bandgap of 2.3 eV and the presence of structural defects in alkaline-doped Cu2 O films. The Mott-Schottky plot shows the flat band potentials of the alkaline-doped Cu2 O films to be approximately −0.1 V and the hole concentrations in the order of 10 17 cm −3 . Significantly, the Cu2 O:Li film photocathode exhibits a higher photocurrent of −2.2 mA cm −2 at a potential of −0.6 V vs Ag/AgCl which are greater than those of Cu2 O:K and Cu2 O:Na films due to greater preferred orientation degrees along (111) and less structural defects, because the ionic radii of Cu and Li is similar. These results demonstrate the great potential of alkaline doped Cu2 O films in solar-related applications. Highlights: Three alkaline-doped Cu2 O films were synthesized by electrodeposition route. Substitution of alkaline ions in the Cu2 O lattice can be confirmed by XRD. High PEC activity of Cu2 O:Li film was achieved the photocurrent of −2.2 mA cm −2 .