Fundamental studies of grain-boundary passivation in polycrystalline silicon with application to improved photovoltaic devices

Technical Report · Sat Aug 01 00:00:00 EDT 1981

OSTI ID:6302518

Seager, C H; Ginley, D S

Theoretical studies of grain boundaries subject to uniform illumination have been completed. Barrier heights and recombination velocities for silicon grain boundaries have been calculated and are shown to be in good agreement with recently obtained transport measurements on uniformly illuminated silicon bicrystals. Improved calculations of the Hall effect in polycrystalline solids are also presented along with assessments of the ability of effective circuit models to account for the anomalously low carrier concentrations measured in small grain polycrystalline silicon. Preliminary optimization of some new methods for hydrogen passivation has been completed. Almost complete removal of EBIC grain boundary losses can now be achieved in times as short as twenty minutes. In addition, progress has been made in the identification and characterization of infrared vibrational modes associated with grain boundary-bonded hydrogen. The effects of fluorine and oxygen treatments on silicon grain boundaries have also been determined. These agents appear to increase grain boundary potential barrier heights in n-type silicon in marked contrast to the effect of hydrogen.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6302518
• Report Number(s): SAND-81-1950; ON: DE82000825
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
CRYSTAL STRUCTURE
CRYSTALS
ELEMENTS
ENERGY GAP
FLUORINE
GRAIN BOUNDARIES
HALL EFFECT
HALOGENS
HYDROGEN ADDITIONS
MATERIALS
MATHEMATICAL MODELS
MICROSTRUCTURE
N-TYPE CONDUCTORS
NONMETALS
OSCILLATION MODES
OXYGEN
PASSIVATION
POLYCRYSTALS
RECOMBINATION
SEMICONDUCTOR MATERIALS
SEMIMETALS
SILICON