Abstract
n-Type Si electrodes in MeOH solvent with 0.2 M (1-hydroxyethyl)ferrocene, 0.5 mM (1-hydroxyethyl)ferricenium, and 1.0 M LiClO4 exhibit air mass 2 conversion efficiencies of 10.1% for optical energy into electricity. We observe open-circuit voltages of 0.53 V and short-circuit quantum efficiencies for electron flow of nearly unity. The fill factor of the cell does not decline significantly with increases in light intensity, indicating substantial reduction in efficiency losses in MeOH solvent compared to previous nonaqueous n-Si systems. Matte etch texturing of the Si surface decreases surface reflectivity and increases photocurrent by 50% compared to shiny, polished Si samples. The high values of the open-circuit voltage observed are consistent with the presence of a thin oxide layer, as in a Schottky metal-insulator-semiconductor device, which yields decreased surface recombination and increased values of open-circuit voltage and short-circuit current. The n-Si system was shown to provide sustained photocurrent at air mass 2 levels (20 mA/cm2) for charge through the interface of >2,000 C/cm2. The n-Si/MeOH system represents a liquid junction cell that has exceeded the 10% barrier for conversion of optical energy into electricity.
Keywords: solar energy conversion, nonaqueous silicon photoanodes
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bard A. J. Photoelectrochemistry. Science. 1980 Jan 11;207(4427):139–144. doi: 10.1126/science.207.4427.139. [DOI] [PubMed] [Google Scholar]
- Legg K. D., Ellis A. B., Bolts J. M., Wrighton M. S. n-Type Si-based photoelectrochemical cell: New liquid junction photocell using a nonaqueous ferricenium/ferrocene electrolyte. Proc Natl Acad Sci U S A. 1977 Oct;74(10):4116–4120. doi: 10.1073/pnas.74.10.4116. [DOI] [PMC free article] [PubMed] [Google Scholar]