skip to main content

DOE PAGESDOE PAGES

Title: Efficiency limits for photoelectrochemical water-splitting

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.
Authors:
 [1] ;  [2] ;  [2]
  1. NG Next, Redondo Beach, CA (United States); California Inst. of Technology (CalTech), Pasadena, CA (United States). Dept. of Chemistry and Chemical Engineering; California Inst. of Technology (CalTech), Pasadena, CA (United States). Division of Engineering and Applied Sciences; California Inst. of Technology (CalTech), Pasadena, CA (United States). Joint Center for Artificial Photosynthesis
  2. California Inst. of Technology (CalTech), Pasadena, CA (United States). Division of Engineering and Applied Sciences; California Inst. of Technology (CalTech), Pasadena, CA (United States). Joint Center for Artificial Photosynthesis
Publication Date:
Grant/Contract Number:
SC0004993
Type:
Accepted Manuscript
Journal Name:
Nature Communications
Additional Journal Information:
Journal Volume: 7; Journal ID: ISSN 2041-1723
Publisher:
Nature Publishing Group
Research Org:
California Inst. of Tech., Pasadena, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1430242