Dynamic aspects of the dye-sensitized photoconductivity of semiconductors. Technical progress report, April 1, 1981-March 31, 1983

Technical Report · Fri Jan 01 04:00:00 EST 1982

OSTI ID:6578145

Goncalves, A M.P.

Research efforts have followed two parallel lines. First, fluorescence lifetime measurements on dye monolayers adsorbed on semiconductor and insulator surfaces, aimed at exploring processes which compete with injection. Second, construction of a fast transient absorption/gain spectrometer, to be used in measurements of the time evolution of surface oxidized dyes to probe the competition between recombination and escape. The fluorescence from rhodamine B and eosin molecules adsorbed on semiconductor (tin oxide and indium oxide) surfaces was monitored. The fluorescence decay curves yielded lifetimes in the range 50 to 60 ps, with an estimated 10 ps error limit in either direction. This corresponds to a lifetime nearly two order of magnitude shorter than in solution. Similar experiments were done with the same two dyes adsorbed on plain glass and on synthetic quartz. The fluorescence lifetimes were even shorter on these materials. The short fluorescence lifetimes of the dyes on both types of materials are most likely the result of effective energy transfer followed by quenching of the excitation at nonfluorescent impurities or defects such as dye aggregates. The conclusion that injection occurs with considerably less than unity efficiency has direct implication for current models of the low overall efficiencies of cells based on these dye/semiconductor systems.

• Research Organization: Temple Univ., Philadelphia, PA (USA)
• DOE Contract Number: AC02-81ER10881
• OSTI ID: 6578145
• Report Number(s): DOE/ER/10881-T1; ON: DE83003909
• Country of Publication: United States
• Language: English

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AMINES
CARBOXYLIC ACIDS
CHALCOGENIDES
DYES
EFFICIENCY
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTROCHEMICAL CELLS
ELECTROLYTIC CELLS
EOSIN
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HYDROXY ACIDS
INDICATORS
INDIUM COMPOUNDS
INDIUM OXIDES
LUMINESCENCE
MATERIALS
ORGANIC ACIDS
ORGANIC BROMINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOCONDUCTIVITY
PHOTOELECTROCHEMICAL CELLS
PHOTOELECTROLYTIC CELLS
PHYSICAL PROPERTIES
REAGENTS
RESEARCH PROGRAMS
RHODAMINES
SEMICONDUCTOR MATERIALS
SOLAR EQUIPMENT
TIN COMPOUNDS
TIN OXIDES