skip to main content


Title: Employing overlayers to improve the performance of Cu 2BaSnS 4 thin film based photoelectrochemical water reduction devices

Earth-abundant copper-barium-thiostannate Cu 2BaSnS 4 (CBTS)-based thin films have recently been reported to exhibit the optoelectronic and defect properties suitable as absorbers for photoelectrochemical (PEC) water splitting and the top cell of tandem photovoltaic solar cells. However, the photocurrents of CBTS-based PEC devices are still much lower than the theoretical value, partially due to ineffective charge collection at CBTS/water interface and instability of CBTS in electrolytes. Here, we report on overcoming these issues by employing overlayer engineering. We find that CdS/ZnO/TiO 2 overlayers can significant-ly improve the PEC performance, achieving saturated cathodic photocurrents up to 7.8 mA cm -2 at the potential of -0.10 V versus reversible hydrogen electrode (RHE) in a neutral electrolyte solution, which is much higher than the best bare CBTS film attaining a photocurrent of 4.8 mA cm -2 at the potential of -0.2 V versus RHE. Finally, our results suggest a viable approach for improving the performance of CBTS-based PEC cells.
ORCiD logo [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [2] ;  [2] ;  [1] ;  [1] ; ORCiD logo [1]
  1. The Univ. of Toledo, Toledo, OH (United States)
  2. National Renewable Energy Lab. (NREL), Golden, CO (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0897-4756
Grant/Contract Number:
AC36-08GO28308; AC02-05CH11231; CHE-1230246; DMR-1534686
Accepted Manuscript
Journal Name:
Chemistry of Materials
Additional Journal Information:
Journal Volume: 29; Journal Issue: 3; Journal ID: ISSN 0897-4756
American Chemical Society (ACS)
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Science (SC), Workforce Development for Teachers and Scientists (WDTS) (SC-27); National Science Foundation (NSF)
Country of Publication:
United States
08 HYDROGEN; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; optoelectronics; absorbers; photoelectrochemical water splitting; overlayer engineering
OSTI Identifier: