Efficiency limits for photoelectrochemical water-splitting
Abstract
Theoretical limiting efficiencies have a critical role in determining technological viability and expectations for device prototypes, as evidenced by the photovoltaics community's focus on detailed balance. However, due to their multicomponent nature, photoelectrochemical devices do not have an equivalent analogue to detailed balance, and reported theoretical efficiency limits vary depending on the assumptions made. Here we introduce a unified framework for photoelectrochemical device performance through which all previous limiting efficiencies can be understood and contextualized. Ideal and experimentally realistic limiting efficiencies are presented, and then generalized using five representative parameters—semiconductor absorption fraction, external radiative efficiency, series resistance, shunt resistance and catalytic exchange current density—to account for imperfect light absorption, charge transport and catalysis. Finally, we discuss the origin of deviations between the limits discussed herein and reported water-splitting efficiencies. This analysis provides insight into the primary factors that determine device performance and a powerful handle to improve device efficiency.
Additional Information
© 2016 The Aurhor(s). This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ Received: 29 February 2016. Accepted: 21 October 2016. Published online: 02 December 2016. This material is based upon work performed by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award No. DE-SC0004993. We are grateful to Dr E. Warmann for useful discussions regarding the impact of external radiative efficiency on photodiode efficiency. Author Contributions: K.T.F. and H.J.L. designed the study and wrote the paper, K.T.F. executed the calculations and analysis, and H.J.L. and H.A.A. advised. All authors reviewed and commented on the manuscript. Data availability: The AM1.5G spectrum data used for the efficiency calculations was derived from the public domain resource, NREL-RREDC: http://rredc.nrel.gov/solar/spectra/am1.5/. Additional data that support the findings of this study, including source code, are available from the corresponding author upon request. The authors declare no competing financial interests. Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.Attached Files
Published - ncomms13706.pdf
Supplemental Material - ncomms13706-s1.pdf
Supplemental Material - ncomms13706-s2.mov
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Additional details
- PMCID
- PMC5146289
- Eprint ID
- 72718
- Resolver ID
- CaltechAUTHORS:20161212-103759501
- Department of Energy (DOE)
- DE-SC0004993
- Created
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2016-12-12Created from EPrint's datestamp field
- Updated
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2022-04-07Created from EPrint's last_modified field
- Caltech groups
- JCAP