Photovoltaic properties of Au--merocyanine--TiO/sub 2/ sandwich cells. I. Dark electrical properties and transient effects

Journal Article · Wed Dec 15 04:00:00 EST 1982 · J. Chem. Phys.; (United States)

OSTI ID:6875791

Skotheim, T; Yang, J; Otvos, J; Klein, M P

The electrical properties of thin films (200--3000 A) of merocyanine photosensitizing dye sandwiched between a TiO/sub 2/ single crystal doped n type and a thin (200 A) Au metal layer has been studied. Dark current voltage measurements revealed that the current is space-charge limited at high current densities with an electron trapping density of approx.10/sup 17/ cm/sup -3/. This was determined by using TiO/sub 2/ as an electron injecting contact. Interpretation of the kinetics of rise and decay of the photocurrent suggests that the mobility of holes, the majority carriers in merocyanine, is dependent on traps, the dominant trapping level having a depth of 0.11 eV. The decay of the photocurrent is monomolecular at short times and dominated by bimolecular recombination kinetics for long times of the order of seconds. The high series resistance in the merocyanine prevents any band bending in the TiO/sub 2/, as the entire built-in voltage in the junction falls across the merocyanine film. This is supported by capacitance voltage data showing a complete absence of mobile charge carriers in the junction region.

• Research Organization: Laboratory of Chemical Biodynamics, Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720
• OSTI ID: 6875791
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 77:12; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
CAPACITANCE
CARRIER MOBILITY
CHALCOGENIDES
CURRENTS
CYANINE DYES
DIRECT ENERGY CONVERTERS
DYES
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRIC POTENTIAL
ELECTRICAL PROPERTIES
ELECTRICAL TRANSIENTS
ELEMENTS
FILMS
GOLD
METALS
MOBILITY
OXIDES
OXYGEN COMPOUNDS
PHOTOCONDUCTIVITY
PHOTOCURRENTS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
THIN FILMS
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSIENTS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
TRAPPING
VOLTAGE DROP