Study of Cd-chalcogenide/ferri-ferrocyanide photoelectrochemical cells: effect of surface morphology and added salt
The authors carried out an investigation of the Cd-chalcogenide/ferri-ferrocyanide photoelectrochemical cells. In particular, the effect of surface morphology and the effect of added salts upon the characteristics of these cells were investigated. Successive etching with Br/sub 2/ (3%)/methanol, aqua regia, and finally photoetching increases the surface roughness of CdSe (CdS, CdTe) which has a marked effect on the cell characteristics in the ferri-ferrocyanide electrolyte (and polysulfide electrolyte as well). In contrast with polysulfide electrolyte, added salts decrease the output stability of the cell and the onset potential for the photocurrent, which can be explained by the removal of the physiosorbed ferrocyanide ions from the electrode surface by the ions of the salt. On increasing the surface roughness of the electrode, while keeping the salt concentration unchanged, the output stability and the onset potential were increased. A kinetic model is used to explain these phenomena. Thus, added salts can be used to probe the strength of the adsorption of the active electrolyte on the surface of the photoelectrode. Finally, we report on the surface morphology of CdSe and CdTe after irradiation in ferri-ferrocyanide solution and compare our findings to surface morphologies which were observed previously with the help of photoelectrochemical etching (photoetching). It is found that small rectangular crystallites, probably of cadmium ferrocyanide, deposit on the crystal surface during the photocorrosion process in addition to elemental Se(Te).
- Research Organization:
- Department of Plastics Research, The Weizmann Institute of Science, Rehovot
- OSTI ID:
- 6991387
- Journal Information:
- J. Electrochem. Soc.; (United States), Journal Name: J. Electrochem. Soc.; (United States) Vol. 130:11; ISSN JESOA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
140505* -- Solar Energy Conversion-- Photochemical
Photobiological
& Thermochemical Conversion-- (1980-)
ALCOHOLS
AQUA REGIA
BROMINE COMPOUNDS
CADMIUM COMPOUNDS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
COMPLEXES
ELECTROCHEMICAL CELLS
ELECTRODES
ELECTROLYTES
EQUIPMENT
ETCHING
FERRICYANIDES
HALOGEN COMPOUNDS
HYDROXY COMPOUNDS
IRON COMPLEXES
IRRADIATION
KINETICS
METHANOL
MORPHOLOGY
ORGANIC COMPOUNDS
PHOTOELECTROCHEMICAL CELLS
REACTION KINETICS
SALTS
SOLAR EQUIPMENT
SURFACE FINISHING
SURFACE PROPERTIES
TRANSITION ELEMENT COMPLEXES