High-aspect-ratio silicon-cell metallization technical status report. Final report
Two features of the silicon concentrator solar cell are addressed which affect output at high concentration levels. The first is the development of narrow but high electroplated grid lines with improved conductivity. The object is a reduction in cell series resistance without increase in shadowing. This goal is accomplished by electroplating through a thick photo resist mask to produce lines .7 mil wide by .7 mil high. Advance pulse plating techniques are combined with pure silver plating baths to produce a deposit conductivity equal to the bulk silver conductivity (a 1.5 to 2 X improvement over conventional silver plating). The second feature is a double diffused selectively textured front surface. This development employs a deep diffusion in the silicon under the grid lines. Only the non grid line open area is selectively texture etched removing the deep junction. This open textured area is then given a second shallow diffusion for optimum cell efficiency. This selective procedure maintains the original highly polished wafer surface under the grid lines so that high resolution narrow grid lines are possible. The double diffusion protects the junction from metal diffusion while enabling the optimum shallow junction in the illuminated regions. Combining these two features has produced a large area concentrator cells (8 cm/sup 2/) with peak efficiency above 16% and exhibiting a broad peak efficiency extending from 50 to 175 suns above 15%.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Boeing Aerospace Co., Seattle, WA (USA)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 5428704
- Report Number(s):
- SAND-81-7033; ON: DE82011687
- Resource Relation:
- Other Information: Portions of document are illegible
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CONCENTRATOR SOLAR CELLS
ELECTRIC CONTACTS
ETCHING
GRIDS
SILICON SOLAR CELLS
SILVER
ELECTROPLATING
ASPECT RATIO
DESIGN
DIFFUSION
EFFICIENCY
ELECTRIC CONDUCTIVITY
HYDRAZINE
MASKING
OPTIMIZATION
ROUGHNESS
TEXTURE
DEPOSITION
DIRECT ENERGY CONVERTERS
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
ELECTRODEPOSITION
ELECTRODES
ELECTROLYSIS
ELEMENTS
EQUIPMENT
LYSIS
METALS
NITROGEN COMPOUNDS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
PLATING
SOLAR CELLS
SOLAR EQUIPMENT
SURFACE COATING
SURFACE FINISHING
SURFACE PROPERTIES
TRANSITION ELEMENTS
140501* - Solar Energy Conversion- Photovoltaic Conversion