气候变化领域集成服务门户(CCPortal): Quantification of the loss mechanisms in emerging water splitting photoanodes through empirical extraction of the spatial charge collection efficiency

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DOI	10.1039/c7ee03486e
	Quantification of the loss mechanisms in emerging water splitting photoanodes through empirical extraction of the spatial charge collection efficiency
	Segev G.; Jiang C.-M.; Cooper J.K.; Eichhorn J.; Toma F.M.; Sharp I.D.
发表日期	2018
ISSN	17545692
起始页码	904
结束页码	913
卷号	11 期号:4
英文摘要	The operando quantification of surface and bulk losses is key to developing strategies for optimizing photoelectrodes and realizing high efficiency photoelectrochemical solar energy conversion systems. This is particularly true for emerging thin film semiconductors, in which photocarrier diffusion lengths, surface and bulk recombination processes, and charge separation and extraction limitations are poorly understood. Insights into mechanisms of efficiency loss can guide strategies for nanostructuring photoelectrodes, engineering interfaces, and incorporating catalysts. However, few experimental methods are available for direct characterization of dominant loss processes under photoelectrochemical operating conditions. In this work, we provide insight into the function and limitations of an emerging semiconductor photoanode, γ-Cu3V2O8, by quantifying the spatial collection efficiency (SCE), which is defined as the fraction of photogenerated charge carriers at each point below the surface that contributes to the measured current. Analyzing SCE profiles at different operating potentials shows that increasing the applied potential primarily acts to reduce surface recombination rather than to increase the thickness of the space charge region under the semiconductor/electrolyte interface. Comparing SCE profiles obtained with and without a sacrificial reagent allows surface losses from electronically active defect states to be distinguished from performance bottlenecks arising from slow reaction kinetics. Combining these insights promotes a complete understanding of the photoanode performance and its potential as a water splitting photoanode. More generally, application of the SCE extraction method can aid in the discovery and evaluation of new materials for solar water splitting devices by providing mechanistic details underlying photocurrent generation and loss. © 2018 The Royal Society of Chemistry.
英文关键词	Electrochemistry; Energy conversion; Reaction kinetics; Solar energy; Charge collection efficiency; Performance bottlenecks; Photocurrent generations; Photogenerated charge carriers; Semiconductor/electrolyte interfaces; Solar water splitting; Surface recombinations; Thin film semiconductors; Extraction; catalysis; catalyst; development strategy; efficiency measurement; electrochemical method; electrode; electrolyte; energy efficiency; equipment; experimental study; extraction method; performance assessment; photolysis; reaction kinetics; separation; solar power
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/190282
作者单位	Chemical Sciences Division, Lawrence Berkeley National Laboratoy, Berkeley, CA 94720, United States; Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratoy, Berkeley, CA 94720, United States; Walter Schottky Institut and Physik Department, Technische Universität München, Garching, 85748, Germany
推荐引用方式 GB/T 7714	Segev G.,Jiang C.-M.,Cooper J.K.,et al. Quantification of the loss mechanisms in emerging water splitting photoanodes through empirical extraction of the spatial charge collection efficiency[J],2018,11(4).
APA	Segev G.,Jiang C.-M.,Cooper J.K.,Eichhorn J.,Toma F.M.,&Sharp I.D..(2018).Quantification of the loss mechanisms in emerging water splitting photoanodes through empirical extraction of the spatial charge collection efficiency.Energy & Environmental Science,11(4).
MLA	Segev G.,et al."Quantification of the loss mechanisms in emerging water splitting photoanodes through empirical extraction of the spatial charge collection efficiency".Energy & Environmental Science 11.4(2018).