Ternary Chalcogenide‐Based Photoelectrochemical Cells: IV . Further Characterization of the Polysulfide Systems
| Autor: | Gary Hodes, Yehudith Mirovsky, W. Giriat, Geulah Dagan, David Cahen, Margot Lubke |
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| Rok vydání: | 1985 |
| Předmět: |
Photocurrent
Materials science Renewable Energy Sustainability and the Environment Photoelectrochemistry Inorganic chemistry Oxide Analytical chemistry Electrolyte Photoelectrochemical cell Condensed Matter Physics Surfaces Coatings and Films Electronic Optical and Magnetic Materials Light intensity chemistry.chemical_compound chemistry Selenide Materials Chemistry Electrochemistry Polysulfide |
| Zdroj: | Journal of The Electrochemical Society. 132:1062-1070 |
| ISSN: | 1945-7111 0013-4651 |
| DOI: | 10.1149/1.2114016 |
| Popis: | The photoelectrochemistry of n-CuInS/sub 2/ and CuInSe/sub 2/ in polysulfide electrolyte is studied with particular emphasis on the pretreatments of the electrodes and on their output stability. The use of Cd doping, (photoelectro) chemical etching, and mild air oxidation all were found to improve electrode performance. The effect of air oxidation was reproducible only for the diselenide, where it improved the fill factor and, because of a negative shift of the flatband potential, the open-circuit voltage. Optimized cells showed, at elevated temperatures, conversion efficiencie around 5 and 7.5% for the sulfide and selenide, respectively. The positive temperature dependence of the photo-I-V characteristics at both low and high illumination intensities, the existence of optimal polysulfide solution compositions, the linear dependence of the photocurrent on the light intensity, and the effects of temperature, solution composition, and initial current density on the photocurrent decrease during the first minute of operation of the cells, are ascribed to limitations of the charge-transfer process across the solid/liquid interface. Thermally activated rates of ad- and desorption of sulfur containing solution species on the semiconductor surface and/or the presence of adsorption-induced electronic states in the bandgap are postulated as causes for this behavior. Notwithstanding these limitations the cellsmore » ar resistant to photocorrosion, after the initial decrease is arrested, in contrast to what is known for similar Cd-chalcogenide-based systems. We suggest that this stability, which persists under load and at high light intensities, is due to the strength and character of the bonds in CuIn-dichalcogenides, or to the presence of a top layer of indium oxide in which recombination will take place, or to both.« less |
| Databáze: | OpenAIRE |
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