Vacuum die casting of silicon sheet for photovoltaic applications. Second quarterly report, 1 July-30 September 1979
The objective of this program is to develop a vacuum die-casting process for producing silicon sheet suitable for photovoltaic cells and to develop production techniques for optimization of polycrystalline silicon solar cell output. Efforts will examine process methods which are directed toward minimum cost processing of silicon into a quality suitable for producing solar cells with a terrestrial efficiency greater than 12% and having the potential to be scaled for large quantity production. In the vacuum die casting technique, silicon is melted under vacuum, and an evacuated die with a thin rectangular cavity is inserted into the melt. Liquid silicon is then injected into the die using a positive pressure of an inert gas. The vacuum die casting process requires a die which is not wetted by molten silicon and does not react with it. A variety of potential die materials were evaluated during this period and a number of casting attempted. A standard process has been demonstrated for polycrystalline solar cells using Wacker SILSO material in both aerospace and terrestrial manufacturing sequences. The cells show excellent curve fill factors with good efficiency but some current output reduction due to lowered long wavelength response. An experiment to evaluate phosphorous diffusion scattering for polycrystalline material is in progress. The use of screen printed aluminum to achieve a back surface field has resulted in enhanced red response but open circuit voltages have not exceeded 565 mV for material with a bulk resistivity ranging from 1 to 5 ohm-cm.
- Research Organization:
- ARCO Solar, Inc., Chatsworth, CA (USA)
- Sponsoring Organization:
- USDOE Solar Energy; National Aeronautics and Space Administration (NASA)
- DOE Contract Number:
- NAS-7-100-955325
- OSTI ID:
- 5568369
- Report Number(s):
- DOE/JPL/955325-2
- Country of Publication:
- United States
- Language:
- English
Similar Records
Silicon solar cell process development, fabricaton, and analysis. Second quarterly report, January thru March, 1979
Silicon solar cell process development, fabrication and analysis. First quarterly report, June 15--September 30, 1978
Related Subjects
36 MATERIALS SCIENCE
SILICON
VACUUM CASTING
SILICON SOLAR CELLS
FABRICATION
ALUMINIUM
BORON NITRIDES
DIES
EFFICIENCY
ELECTRIC CONDUCTIVITY
FILL FACTORS
GRAPHITE
MATERIALS
POLYCRYSTALS
QUARTZ
SCREEN PRINTING
SHEETS
SILICON NITRIDES
SODIUM FLUORIDES
SODIUM SILICATES
WETTABILITY
ALKALI METAL COMPOUNDS
BORON COMPOUNDS
CARBON
CASTING
CHALCOGENIDES
CRYSTALS
DEPOSITION
DIRECT ENERGY CONVERTERS
ELECTRICAL PROPERTIES
ELEMENTS
EQUIPMENT
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
METALS
NITRIDES
NITROGEN COMPOUNDS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
PNICTIDES
SEMIMETALS
SILICATES
SILICON COMPOUNDS
SILICON OXIDES
SODIUM COMPOUNDS
SOLAR CELLS
SOLAR EQUIPMENT
SURFACE COATING
140501* - Solar Energy Conversion- Photovoltaic Conversion
360601 - Other Materials- Preparation & Manufacture