Electrochemical photovoltaic cells/stabilization and optimization of II-VI semiconductors

Technical Report · Sun Mar 01 04:00:00 EST 1981

DOI:https://doi.org/10.2172/5961949· OSTI ID:5961949

Noufi, R.; Tench, D.; Warren, L.

The overall goal of this program is to provide the basis for designing a practical electrochemical solar cell based on the II-VI compound semiconductors. Emphasis is on developing new electrolyte redox systems and electrode surface modifications which will stabilize the II-VI compounds against photodissolution without seriously degrading the long-term solar response. Factors limiting the short circuit current of the n-CdSe photoanodes in the methanol/ferro-ferricyanide system were identified. Although the methanol/ferro-ferricyanide solution itself was found to be photolytically unstable, study of this system led to the identification of more promising nonaqueous redox electrolytes. Additional work on redox couple stabilizaton of n-CdX photoanodes was focused on both one- and two-electron couples. Very promising results were obtained for the alkylammonium chloro-Fe(II,III) couple in acetonitrile. Conducting polymer films of polypyrrole photoelectrochemically deposited onto n-type semiconductors were shown to protect these electrode materials from photodecomposition while permitting electron exchange with the electrolyte, but poor adhesion has remained a key problem. Recently, improved adhesion has been attained for roughened semiconductor surfaces. In a basic aqueous ferro-ferricyanide electrolyte containing cyanide ion, the measured open circuit voltage for n-CdTe was 1.3 V, which is practically the bandgap for this material. It now appears that polypyrrole films are to some extent permeable to solvent/solute species since the film stability depends on the nature of the redox electrolyte, and semiconductor decomposition products seem to form underneath film in some cases. Some work with polyaniline films was performed. Work on evaluating photocapacitance spectroscopy as a means of in situ characterization of semiconductor electrodes was focused on developing a reliable measurement technique.

• Research Organization: Rockwell International Corp., Thousand Oaks, CA (USA)
• DOE Contract Number: AC02-77CH00178
• OSTI ID: 5961949
• Report Number(s): SERI/TR-9276-T3; ON: DE82002093
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140505* -- Solar Energy Conversion-- Photochemical
Photobiological
& Thermochemical Conversion-- (1980-)
ALCOHOLS
ANODES
ARSENIC COMPOUNDS
ARSENIDES
AZOLES
CADMIUM COMPOUNDS
CADMIUM SELENIDES
CAPACITANCE
CHALCOGENIDES
CHEMICAL REACTIONS
CHLORINE COMPLEXES
COATINGS
COMPLEXES
CURRENTS
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
ELECTROCHEMICAL CELLS
ELECTRODES
ELECTROLYTES
ELEMENTS
EQUIPMENT
FERRICYANIDES
FERROCYANIDES
FILMS
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
IRON COMPLEXES
METALS
METHANOL
OPTIMIZATION
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOANODES
PHOTOELECTROCHEMICAL CELLS
PHYSICAL PROPERTIES
PNICTIDES
POLYMERS
PYRROLES
REDOX REACTIONS
SELENIDES
SELENIUM COMPOUNDS
SOLAR EQUIPMENT
SPECTRAL RESPONSE
STABILIZATION
TRANSITION ELEMENT COMPLEXES