Investigation of photovoltaic mechanisms in polycrystalline thin-film solar cells. Final technical report: Volume 1, August 1, 1980-October 31, 1981

Technical Report · Wed May 05 04:00:00 EDT 1982

DOI:https://doi.org/10.2172/5357252· OSTI ID:5357252

Temofonte, T. A.; Szedon, J. R.; O'Keeffe, T. W.

The purpose of this work was to characterize and control grain boundary influences on the performance of solar cells fabricated in polycrystalline silicon. The most significant accomplishments were made using scanned-laser spot characterizations of grain boundary effects on photocurrent. We were able to modulate the peak photocurrent suppression at boundaries, obtaining values of 1% or less after plasma hydrogenation and of 40% or greater after certain high-temperature heat treatments, simulating the conditions of impurity diffusion for junction formation. Conventional DLTS measurements on Wacker SILSO polysilicon material revealed deep centers at a concentration of about 1 x 10/sup 13/ cm/sup -3/ having an energy similar to that for molybdenum. The center is probably not due to molybdenum, since such concentrations of that impurity would not allow good photovoltaic performance in the material. Problems encountered with implementing lateral DLTS measurements are discussed. Comparisons of behavior were made of current-voltage behavior in MIS and pn-junction barrier solar cells which were fabricated in polycrystalline silicon containing low (2 x 10/sup 13/ cm/sup -3/) and moderate (1 x 10/sup 14/ cm/sup -3/) concentrations of the lifetime-killing impurity titanium. Results are treated in terms of differences with regard to baseline cells, free of deliberately introduced impurity.

• Research Organization: Westinghouse Research and Development Center, Pittsburgh, PA (USA)
• DOE Contract Number: AC02-77CH00178
• OSTI ID: 5357252
• Report Number(s): SERI/TR-9233-1-T3-Vol.1; ON: DE82017683
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
AUGER ELECTRON SPECTROSCOPY
CHALCOGENIDES
COMPARATIVE EVALUATIONS
CRYSTAL STRUCTURE
CRYSTALS
CURRENTS
DIRECT ENERGY CONVERTERS
ELECTRIC CURRENTS
ELECTRIC POTENTIAL
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
ELEMENTS
EQUIPMENT
FILMS
GRAIN BOUNDARIES
HEAT TREATMENTS
HYDROGEN
IMPURITIES
JUNCTIONS
LASER RADIATION
METALS
MICROSTRUCTURE
MIS SOLAR CELLS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
P-N JUNCTIONS
PASSIVATION
PHOTOCURRENTS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
POLYCRYSTALS
RADIATIONS
SEMICONDUCTOR JUNCTIONS
SILICON SOLAR CELLS
SOLAR CELLS
SOLAR EQUIPMENT
SPECTROSCOPY
TITANIUM
TRANSIENTS
TRANSITION ELEMENTS