Abstract
Earth-abundant copper-barium-thiostannate Cu2BaSnS4 (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/TiO2 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. Our results suggest a viable approach for improving the performance of CBTS-based PEC cells.
Original language | American English |
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Pages (from-to) | 916-920 |
Number of pages | 5 |
Journal | Chemistry of Materials |
Volume | 29 |
Issue number | 3 |
DOIs | |
State | Published - 14 Feb 2017 |
NREL Publication Number
- NREL/JA-5900-67785
Keywords
- absorbers
- optoelectronics
- overlayer engineering
- photoelectrochemical water splitting