Photoelectrochemical Stability of Electrodeposited Cu2O Films

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• 作者：Lingling Wu ; Lok-kun Tsui ; Nathan Swami ; Giovanni Zangari
• 刊名：Journal of Physical Chemistry C
• 出版年：2010
• 出版时间：July 8, 2010
• 年：2010
• 卷：114
• 期：26
• 页码：11551-11556
• 全文大小：336K
• 年卷期：v.114,no.26(July 8, 2010)
• ISSN：1932-7455

文摘

We report on the photoelectrochemical stability of electrodeposited films of cuprous oxide (Cu₂O) in aqueous solutions. p-type Cu₂O was electrodeposited from an alkaline lactate solution onto Au substrates with a (111) preferred orientation. The as-deposited films exhibit a strong (111) orientation and a columnar morphology, terminating at the surface with pyramidal features. Stability of the photoelectrochemical response was studied via repeated cycling polarization and by monitoring the photocurrent within a voltage window where only the CuO/Cu₂O transformation would occur. The Cu₂O film morphology changes from a dense structure to a more stable network of elongated leaf-like crystals. We attributed this behavior to the energy differences among the various crystallographic facets of Cu₂O, with the {111} facets being the most stable. Photocurrent evolution over time was explained in terms of an initial increase in surface area at the start of the process, followed by a decrease due to increased recombination losses resulting from having only the {111} surface exposed to the electrolyte.