Development and evaluation of die and container materials. First quarterly progress report, October 1--December 31, 1977. Silicon Sheet Task, Low Cost Silicon Solar Array Project. [For handling molten silicon for crystal growth]
The JPL Low Cost Silicon Solar Array Project has been established with the goal of decreasing the cost of solar photovoltaic arrays for electrical power generation. Methods of producing silicon sheet for solar cells are under active development as one of several tasks designed to achieve this objective. In the crystal growing processes a refractory crucible is required to hold the molten silicon while in the ribbon processes an additional refractory shaping die is needed to enable silicon ribbon to be produced. In several ribbon processes the high temperature materials are a limiting factor in the development of the technique. The objective of this study is to develop and evaluate refractory die and container materials. First quarter studies are reported. Commercial high purity ultrafine Si/sub 3/N/sub 4/, Al/sub 2/O/sub 3/ and SiO/sub 2/ powders were vacuum dried and stored under nitrogen in sealed containers. Extensive analysis of the chemical, physical and morphological characteristics of these powders has been performed. The preparation of high purity A1N powder is being investigated by elevated temperature gas phase nucleation reactions involving (1) the reaction of AlCl/sub 3/(g) and NH/sub 3/ and (2) the reaction between AlCl(g) and NH/sub 3/. While optimization of reaction (1) has not been completed, it appears that this process will only give low yields. Preliminary evaluation of reaction (2) has not yet proceeded far enough to permit definitive analysis of results. The interaction of molten silicon with fused quartz was examined in a Knudsen cell using a mass spectrometer. The solubility of oxygen at the melting point of silicon was calculated to be 1.78 x 10/sup 18/ atoms/cm/sup 3/, and the activity coefficients of oxygen and silicon monoxide, the major vapor species, were calculated to be 4.83 x 10/sup -24/ and 7.01 x 10/sup -5/, respectively.
- Research Organization:
- Battelle Columbus Labs., OH (United States)
- DOE Contract Number:
- NAS 7-100-954876
- OSTI ID:
- 7152718
- Report Number(s):
- DOE/JPL/954876-1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Development and evaluation of die and container materials. Third quarterly progress report, April 1--June 30, 1978. [For molten silicon]
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Related Subjects
36 MATERIALS SCIENCE
CRUCIBLES
MATERIALS
DIES
SILICON
CRYSTAL GROWTH
ALUMINIUM OXIDES
CHEMICAL ANALYSIS
CONTAINERS
IMPURITIES
MASS SPECTROSCOPY
POWDERS
QUARTZ
SILICON NITRIDES
SILICON OXIDES
SILICON SOLAR CELLS
ALUMINIUM COMPOUNDS
CHALCOGENIDES
DIRECT ENERGY CONVERTERS
ELEMENTS
NITRIDES
NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PNICTIDES
SEMIMETALS
SILICON COMPOUNDS
SOLAR CELLS
SPECTROSCOPY
140501* - Solar Energy Conversion- Photovoltaic Conversion
360601 - Other Materials- Preparation & Manufacture