Electrochemical photovoltaic cells/stabilization and optimization of II-VI semiconductors. Third technical progress report, 1 October-31 December 1979

Technical Report · Sun Jan 20 04:00:00 EST 1980

OSTI ID:6630906

Nouffi, 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. The bulk electrode material properties are also being optimized to provide the maximum solar conversion efficiency and greatest inherent electrode stability. Stabilization of n-CdSe against photodissolution has been achieved for the methanol/tetraethylammonium ferro-ferricyanide system. No degradation of the photocurrent or the electrode surface, even in the presence of traces of water, has been observed for runs up to 700 h at 6 mA/cm/sup 2/ and AM1 light intensity. In recent studies with higher quality single crystal CdSe as well as polycrystalline CdTe-CdSe photoanodes, stable photocurrents of 7.5 mA/cm/sup 2/, corresponding to 4.4% conversion efficiency have been obtained. Through the use of highly purified ferro-ferricyanide electrolytes and/or organic dications, higher conversion efficiencies should be attainable. Preliminary evaluation of a series of sulfur-containing 1,2-dithiolene metal complexes for stabilization of CdX (X=Se, Te, or S) photoanodes in acetonitrile solution has been completed. In certain cases, effective hole capture is indicated and favorable negative shifts in the flatband potentials have been observed. A conducting polymer film (derived from pyrrole) has been electrochemically deposited on a semiconductor electrode. These electrochemically generated polymer films seem to be exceptionally stable and adherent. Studies of the cyanide ion as an electron-transfer mediator in aqueous Fe(CN)/sub 6//sup 3 -///sup 4 -/ electrolytes, and new directions for chemical modification of CdX electrodes are also discussed.

• Research Organization: Rockwell International Corp., Thousand Oaks, CA (USA)
• DOE Contract Number: AC02-77CH00178
• OSTI ID: 6630906
• Report Number(s): SERI/PR-8002-1-T3; ON: DE83005684
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140505* -- Solar Energy Conversion-- Photochemical
Photobiological
& Thermochemical Conversion-- (1980-)
ACETONITRILE
ADDITIVES
ANODES
CADMIUM COMPOUNDS
CADMIUM SELENIDES
CADMIUM SULFIDES
CADMIUM TELLURIDES
CHALCOGENIDES
CHEMICAL REACTIONS
COMPLEXES
CURRENTS
DATA
DECOMPOSITION
EFFICIENCY
ELECTRIC CURRENTS
ELECTROCHEMICAL CELLS
ELECTRODES
ELECTROLYTES
EQUIPMENT
EXPERIMENTAL DATA
FERRICYANIDES
FERROCYANIDES
FILMS
INFORMATION
INORGANIC PHOSPHORS
IRON COMPLEXES
NITRILES
NUMERICAL DATA
OPTIMIZATION
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOSPHORS
PHOTOANODES
PHOTOCURRENTS
PHOTOELECTROCHEMICAL CELLS
POLYMERS
REDOX REACTIONS
SELENIDES
SELENIUM COMPOUNDS
SOLAR EQUIPMENT
STABILIZATION
SULFIDES
SULFUR COMPOUNDS
TELLURIDES
TELLURIUM COMPOUNDS
TRANSITION ELEMENT COMPLEXES
VOLTAMETRY