Low-cost high-performance silicon concentrator cells

Technical Report · Fri Feb 01 04:00:00 EST 1985

OSTI ID:5886369

Borden, P G

Silicon solar cells have not performed well at high concentrations because of excess emitter and base resistance. The V-groove, or VG silicon solar cell has a novel emitter structure that allows use of wide, closely spaced front contact grid lines without significant obscuration, eliminating emitter resistance almost entirely. The active layers can be relatively thin because rays refract obliquely at the cell front, making it possible to reduce significantly both emitter and base resistance and improve high concentration performance. Efficiencies over 19% at 100 suns and 20/sup 0/C have been obtained with a cell area of .5 x .5 cm. This cell has about 33% of the front surface covered with metal, with a V-groove period of 50 microns and grid line spacing of 83 microns. The cell has a single layer AR coating of silicon nitride. This performance approaches state-of-the-art for silicon concentrator cells and demonstrates the principle of the VG cell. The drop in efficiency at higher concentration, due probably to base resistance, can be overcome by using thinner active layers. Additional features include a structure relatively simple to fabricate and a planar, metallized back surface to facilitate packaging.

• Research Organization: Varian Associates, Palo Alto, CA (USA). Solid State Lab.
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5886369
• Report Number(s): SAND-84-7005; ON: DE85008875
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
ANTIREFLECTION COATINGS
COATINGS
CONCENTRATOR SOLAR CELLS
DESIGN
DIRECT ENERGY CONVERTERS
EFFICIENCY
ELECTRIC CONTACTS
ELECTRICAL EQUIPMENT
EQUIPMENT
ETCHING
FABRICATION
PERFORMANCE
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
SILICON SOLAR CELLS
SOLAR CELLS
SOLAR EQUIPMENT
SURFACE FINISHING