Low-angle silicon-sheet growth. Final technical report, July 1, 1980-June 30, 1981

Technical Report · Tue Sep 01 00:00:00 EDT 1981

OSTI ID:5251143

Locher, J.W.: Bates, H.E.

During this period, 48 experimental crystal growth runs were performed to optimize the LASS growth process. Continuous growth of a 9.02 meter long ribbon at an average rate of 20cm/min was achieved. This ribbon was 2.5cm wide on the average. Wider ribbon was produced at faster growth rates. The best overall result was a 3.9 meter long ribbon that was 3.6cm wide and grown at an average speed of 40cm/min. Solar cell fabrication resulted in 40 cells made and 38 tested. The best efficiency (AM1) achieved was 10.95% with an average of approx. 9.9% for 8 advanced process cells. The relationship between pull speed and ribbon thickness was studied. The experimental data was found to fit a theoretical model derived from first principles. It has been observed that the LASS ribbon exhibits fairly pronounced surface topography. It has become an ongoing effort to attempt to dictate, via process variables, this topography. Currently, ribbon is grown in a highly dendritic mode. Two other modes of growth have been observed which are flat dendritic and cellular. Metallographic observation of grown ribbon has shown that the ribbon cross sectional crystal structure exhibits quantities of twins that usually emanate from surface dendrite peaks. Dislocation densities average about 10/sup 3/cm/sup -2/. High angle grain boundaries and short parallel twin areas abound in sections of ribbon that are comprised of random dendrites. X-ray results show that the ribbon usually grows in a (210) direction with the gross surface normal inclined at 24/sup 0/ from a (1 anti 1 0) direction.

• Research Organization: Energy Materials Corp., South Lancaster, MA (USA)
• DOE Contract Number: AC02-77CH00178
• OSTI ID: 5251143
• Report Number(s): SERI/TR-8041-3-T2; ON: DE82014304
• Resource Relation: Other Information: Portions of document are illegible
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
LASS GROWTH METHOD
OPTIMIZATION
SILICON
CRYSTAL GROWTH
SILICON SOLAR CELLS
FABRICATION
CRYSTALLOGRAPHY
DISLOCATIONS
EFFICIENCY
ELECTRICAL PROPERTIES
GRAIN BOUNDARIES
MATHEMATICAL MODELS
MICROSTRUCTURE
ORIENTATION
TOPOGRAPHY
TWINNING
VALIDATION
CRYSTAL DEFECTS
CRYSTAL GROWTH METHODS
CRYSTAL STRUCTURE
DIRECT ENERGY CONVERTERS
ELEMENTS
EQUIPMENT
LINE DEFECTS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
SEMIMETALS
SOLAR CELLS
SOLAR EQUIPMENT
TESTING
140501* - Solar Energy Conversion- Photovoltaic Conversion
360601 - Other Materials- Preparation & Manufacture