Study of n-type semiconducting cadmium chalcogenide-based photoelectrochemical cells employing polychalcogenide electrolytes

Journal Article · Wed Apr 27 04:00:00 EDT 1977 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00451a001· OSTI ID:7213294

Ellis, A B; Kaiser, S W; Bolts, J M; Wrighton, M S

Studies of CdX-based photoelectrochemical cells in X/sup 2 -//X/sup 2 -//sub n/ electrolytes are reported for X = S, Se, and Te. For eight of the nine electrode/electrolyte combinations we have demonstrated that the n-type semiconducting single-crystal CdX photoelectrodes are stable to anodic dissolution. Only for CdTe in S/sup 2 -//S/sup 2 -//sub n/ do we find that oxidation of the added chalcogenide does not quench the decomposition of CdX typically found in aqueous electrolytes. For all eight remaining elecrolyte/electrode combinations the added chalcogenide is oxidized at the photoelectrode at a rate which precludes anodic dissolution of the CdX. For the stable combinations each electrolyte is capable of being oxidized at the photoelectrode and subsequently reduced at the dark counter electrode to complete a cycle where no net chemical change obtains. For all nine electrolyte/electrode combinations and for the CdX in alkaline H/sub 2/O, the redox level associated with the oxidation of X/sup 2 -/ or with O/sub 2/ evolution is between the valence band and conduction band positions at the semiconductor--electrolyte interface. Thus, energetic requirementsfor X/sup 2 -/ oxidation or O/sub 2/ evolution from H/sub 2/O are met in all cases, but apparently kinetic factors control whether oxidation of X/sup 2 -/ or of H/sub 2/O will be fast compared to anodic dissolution, which is also energetically feasible. For the stable electrode/electrolyte combinations, conversion of optical to electrical energy can be accomplished with efficiencies of > 10 percent for monochromatic visible light. For CdTe or CdSe in the Te/sup 2 -//Te/sub 2//sup 2 -/ electrolyte input power densities of >500 mW/cm/sup 2/ can be converted with a few percent efficiency with no deterioration of properties. Output voltages at maximum power conversion efficiency are of the order of 0.4 V.

• Research Organization: Massachusetts Inst. of Tech., Cambridge
• OSTI ID: 7213294
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 99:9; ISSN JACSA
• Country of Publication: United States
• Language: English

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AQUEOUS SOLUTIONS
CADMIUM COMPOUNDS
CADMIUM SELENIDES
CADMIUM SULFIDES
CADMIUM TELLURIDES
CHALCOGENIDES
CHEMISTRY
DISPERSIONS
ELECTROCHEMICAL CELLS
ELECTROCHEMISTRY
INORGANIC PHOSPHORS
MIXTURES
PHOSPHORS
PHOTOCHEMISTRY
PHOTOVOLTAIC EFFECT
SELENIDES
SELENIUM COMPOUNDS
SOLUTIONS
SULFIDES
SULFUR COMPOUNDS
TELLURIDES
TELLURIUM COMPOUNDS