Effects of Dawson-Type Tungstophosphate on Photoelectrochemical Responses of Cadmium Sulfide Composite Film

• Published in: Journal of physical chemistry. C Vol. 116; no. 10; pp. 6420 - 6426
• Main Authors: Sun, Zhixia, Li, Fengyan, Xu, Lin, Liu, Shuping, Zhao, Mingliang, Xu, Bingbing
• Format: Journal Article
• Language: English
• Published: Columbus, OH American Chemical Society 15-03-2012
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of nanofabrication; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Other materials; Photoluminescence; Physics; Self-assembly; Specific materials; Composite film; Metallates; Atomic force microscopy; Electron-hole recombination; Transient photoconductivity; Organometallic compounds; Luminescence; Fluorescence; Electron transfer; XRD; Thin films; Surface photovoltage; Hydrochlorides; Charge carrier recombination; Energy conversion; IV characteristic; Scanning electron microscopy; Experimental data; Photocurrents; X-ray spectra; Infrared spectra; Cadmium sulfide; Self-assembly; Ultraviolet visible spectrum; X-ray photoelectron spectra
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp2119982

For exploration of the effects of polyoxometalate on the photoelectrochemical properties of cadmium sulfide (CdS), a composite film of poly­(allylamine hydrochloride)-modified CdS (CdS-PAH) and polyoxometalate (K6P2W18O62) has been prepared by the layer-by-layer self-assembly method. The thin film was characterized by UV–vis spectroscopy, infrared spectra, X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy, and scanning electron microscopy. Both photocurrent transient measurement and current–voltage curves displayed that the photocurrent response and power conversion efficiency of the CdS-PAH/P2W18 composite film were markedly enhanced in comparison with those of the single CdS-PAH film. Furthermore, CdS-PAH/P2W18 film exhibited higher photocurrent response intensity than the simple sum of individual components, and polyoxometalate (P2W18) could act as the photoinduced electron transfer shuttle to efficiently suppress electron–hole recombination in CdS. Such a mechanism was further proven by experimental data of fluorescence emission spectra and surface photovoltage spectroscopy. These results demonstrated a new strategy to promote the photocurrent response of CdS via the photoinduced electron transfer from the CdS to P2W18.