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DOI	10.1039/c6ee03505a
	Junction behavior of n-Si photoanodes protected by thin Ni elucidated from dual working electrode photoelectrochemistry
	Laskowski F.A.L.; Nellist M.R.; Venkatkarthick R.; Boettcher S.W.
发表日期	2017
ISSN	17545692
起始页码	570
结束页码	579
卷号	10 期号:2
英文摘要	Si is a desirable photoanode material for use in photoelectrochemical water-splitting devices. However, Si self-passivates during the oxygen evolution half reaction and requires a protection layer to maintain high photoanodic efficiency. Thin evaporated metallic Ni layers have been reported to protect Si while also enhancing the kinetics for oxygen evolution. Maximizing performance of these and related protected/catalyzed semiconductors requires a fundamental understanding of the semiconductor\|catalyst\|solution interface. We use dual-working-electrode (DWE) photoelectrochemistry measurements to directly measure the interface's electronic properties in situ during operation. By controlling the Ni thickness (3, 5, and 20 nm), we confirm that favorable shifts in photocurrent onset are correlated with thinner protection layers. Photoelectrochemical DWE measurements are used to test various prevailing hypotheses for the origin of this behavior. We find evidence that increased photovoltage is due to the development of a spatially inhomogeneous buried junction wherein high barrier regions arise via adventitious SiO2 growth. Thinner protection layers more readily promote this behavior by facilitating solution permeation to the n-Si\|Ni interface. Repeated electrochemical cycling of thicker catalyst layers can achieve similar behavior and improve the photocurrent onset by as much as 300 mV. The results are discussed in the context of the general design principles for metal-insulator-semiconductor protected photoanodes. © 2017 The Royal Society of Chemistry.
英文关键词	Automobile drivers; Catalysts; Electrochemistry; Electrodes; Electronic properties; Metal insulator boundaries; MIS devices; Nickel; Semiconductor junctions; Silica; Electrochemical cycling; Metal-insulator-semiconductors; Photo-electrochemistry; Photoanode materials; Photoelectrochemical water splitting; Photoelectrochemicals; Solution interface; Spatially inhomogeneous; Silicon; catalyst; efficiency measurement; electrochemistry; electrode; electronic equipment; hypothesis testing; performance assessment; reaction kinetics
语种	英语
来源期刊	Energy & Environmental Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/190522
作者单位	Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403, United States; Electroinorganic Chemicals Division, CSIR, Central Electrochemical Research Institute, Karaikudi, Tamilnadu 630003, India
推荐引用方式 GB/T 7714	Laskowski F.A.L.,Nellist M.R.,Venkatkarthick R.,et al. Junction behavior of n-Si photoanodes protected by thin Ni elucidated from dual working electrode photoelectrochemistry[J],2017,10(2).
APA	Laskowski F.A.L.,Nellist M.R.,Venkatkarthick R.,&Boettcher S.W..(2017).Junction behavior of n-Si photoanodes protected by thin Ni elucidated from dual working electrode photoelectrochemistry.Energy & Environmental Science,10(2).
MLA	Laskowski F.A.L.,et al."Junction behavior of n-Si photoanodes protected by thin Ni elucidated from dual working electrode photoelectrochemistry".Energy & Environmental Science 10.2(2017).