Coplanar back contacts for thin silicon solar cells. Final report, 24 Jul. 1978 - 15 Jul. 1980

Technical Report · Thu Jan 01 04:00:00 EST 1981

OSTI ID:5746800

Storti, G; Scheinine, A; Whitehouse, D; Wohlgemuth, J; Wrigley, C; Giuliano, M

The type of coplanar back contact solar cell described was constructed with interdigitated n(+) and p(+) type regions on the back of the cell, such that both contacts are made on the back with no metallization grid on the front. This cell construction has several potential advantages over conventional cells for space use namely, convenience of interconnects, lower operating temperatures and higher efficiency due to the elimination of grid shadowing. However, the processing is more complex, and the cell is inherently more radiation sensitive. The latter problem can be reduced substantially by making the cells very thin (approximately 50 micrometers). Two types of interdigitated back contact cells are possible, the types being dependent on the character of the front surface. The front surface field cell has a front surface region that is of the same conductivity type as the bulk but is more heavily doped. This creates an electric field at the surface which repels the minority carriers. The tandem junction cell has a front surface region of a conductivity type that is opposite to that of the bulk. The junction thus created floats to open circuit voltage on illumination and injects carriers into the bulk which then can be collected at the rear junction. For space use, the front surface field cell is potentially more radiation resistant than the tandem junction cell because the flow of minority carriers (electrons) into the bulk will be less sensitive to the production of recombination centers, particularly in the space charge region at the front surface.

• Research Organization: Solarex Corp., Rockville, MD (USA)
• OSTI ID: 5746800
• Report Number(s): NASA-CR-165272
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
CHARGE CARRIERS
DIRECT ENERGY CONVERTERS
DOPED MATERIALS
ELECTRIC CONTACTS
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
EQUIPMENT
FABRICATION
MATERIALS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
PHYSICAL RADIATION EFFECTS
RADIATION EFFECTS
SILICON SOLAR CELLS
SOLAR CELLS
SOLAR EQUIPMENT