Photovoltaic mechanisms in polycrystalline thin-film silicon solar cells. Final technical report, July 29, 1980-July 28, 1981

Technical Report · Tue Dec 01 00:00:00 EST 1981

DOI:https://doi.org/10.2172/5251079· OSTI ID:5251079

Sopori, B. L.

During this contract period a variety of techniques was developed for physical and electro-optical characterization of defects, grain boundaries (G.B.) and twins in polycrystalline silicon. Chemical etching, copper decoration and IR/VIS microscopy were the main techniques used for characterizing defects and for the determination of dislocation propagation paths in RTR ribbon samples. Three dimensional distributions of dislocations were determined for various grain orientations in RTR ribbons. A new (optical) technique for determination of grain orientations was developed. This technique was applied to determine dominant grain orientations and G.B. misfit angles in the RTR ribbon samples. The small area device fabrication technique was improved to yield devices which do not show any significant edge leakage (for operation as a solar cell). It was found that a parameter ..delta.. V/sub OC/ (difference between the V/sub OC/'s of large area cell and a small area diode) is a good indicator of the diode edge leakage. Devices thus fabricated can be used to determine the influences of the substrate defects on the cell parameters. An analysis of the I-V (dark and illuminated) characteristics can be used to determine the carrier transport mechanisms. Several applications of the two wavelength laser scanner for evaluation of photovoltaic characteristics of unprocessed substrates as well as devices were investigated. Of particular interest is the transverse photovoltage technique for the determination of the electrical activity of a grain boundary. It was shown tht G.B. activity determined by this technique correlates well with that of the voltage pick-off probe signals.

• Research Organization: Solar Energy Research Inst. (SERI), Golden, CO (United States); Motorola, Inc., Phoenix, AZ (USA). Solar Energy Dept.
• DOE Contract Number: AC02-77CH00178
• OSTI ID: 5251079
• Report Number(s): SERI/TR-9234-2-T2; ON: DE82013494
• Resource Relation: Other Information: Portions of document are illegible
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
SILICON
CRYSTAL DEFECTS
GRAIN BOUNDARIES
SILICON SOLAR CELLS
ELECTRICAL PROPERTIES
FABRICATION
CHARGE TRANSPORT
COPPER
DISLOCATIONS
ETCHING
FILMS
LASER RADIATION
LEAKAGE CURRENT
MICROSCOPY
POLYCRYSTALS
RIBBON-TO-RIBBON METHOD
CRYSTAL GROWTH METHODS
CRYSTAL STRUCTURE
CRYSTALS
CURRENTS
DIRECT ENERGY CONVERTERS
ELECTRIC CURRENTS
ELECTROMAGNETIC RADIATION
ELEMENTS
EQUIPMENT
LINE DEFECTS
METALS
MICROSTRUCTURE
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
RADIATIONS
SEMIMETALS
SOLAR CELLS
SOLAR EQUIPMENT
SURFACE FINISHING
TRANSITION ELEMENTS
140501* - Solar Energy Conversion- Photovoltaic Conversion