Silicon-on-ceramic coating process. Silicon sheet growth development for the Large-Area Silicon Sheet and Cell Development Tasks of the Low-Cost Silicon Solar Array Project. Quarterly report No. 8, December 28, 1977--March 28, 1977

Technical Report · Thu Apr 20 00:00:00 EST 1978

DOI:https://doi.org/10.2172/6642891· OSTI ID:6642891

Heaps, J D; Maclolek, R B; Koepke, B; Butter, C D; Schult, S B

A research program to investigate the technical and economic feasibility of producing solar-cell-quality sheet silicon by coating inexpensive ceramic substrates with a thin layer of polycrystalline silicon is described. The coating methods to be developed are directed toward a minimum-cost process for producing solar cells with a terrestrial conversion efficiency of 12 percent or greater. By applying a graphite coating to one face of a ceramic substrate, molten silicon can be caused to wet only that graphite-coated face and produce uniform thin layers of large-grain polycrystalline silicon; thus, only a minimal quantity of silicon is consumed. A dip-coating method for putting silicon on ceramic (SOC) has been shown to produce solar-cell-quality sheet silicon. This method and a continuous coating process also being investigated have excellent scale-up potential which offers an outstanding cost-effective way to manufacture large-area solar cells. A variety of ceramic materials have been dip-coated with silicon. The investigation has shown that mullite substrates containing an excess of SiO/sub 2/ best match the thermal expansion coefficient of silicon and hence produce the best SOC layers. With such substrates, smooth and uniform silicon layers 25 cm/sup 2/ in area have been achieved with single-crystal grains as large as 4 mm in width and several cm in length. Solar cells with areas from 1 to 10 cm/sup 2/ have been fabricated from material withas-grown surface. Recently, an antireflection (AR) coating has been applied to SOC cells. Conversion efficiencies greater than 9% have been achieved without optimizing series resistance characteristics. Such cells typically have open-circuit voltages and short-circuit current densities of 0.51 V and 20 mA/cm/sup 2/, respectively.

• Research Organization: Honeywell Corporate Material Sciences Center, Bloomington, MN (USA)
• DOE Contract Number: NAS-7-100-954356
• OSTI ID: 6642891
• Report Number(s): DOE/JPL/954356-5
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
SILICON
DIP COATING
SILICON SOLAR CELLS
FABRICATION
ANTIREFLECTION COATINGS
BONDING
CERAMICS
DIPPED COATINGS
ECONOMICS
ELECTRIC CONTACTS
FEASIBILITY STUDIES
GRAPHITE
IMPURITIES
MULLITE
OPTIMIZATION
PERFORMANCE
POLYCRYSTALS
PRODUCTION
SHEETS
SUBSTRATES
THERMAL SHOCK
CARBON
COATINGS
CRYSTALS
DEPOSITION
DIRECT ENERGY CONVERTERS
ELECTRICAL EQUIPMENT
ELEMENTS
EQUIPMENT
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
JOINING
MINERALS
NONMETALS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
SEMIMETALS
SOLAR CELLS
SURFACE COATING
140501* - Solar Energy Conversion- Photovoltaic Conversion
360601 - Other Materials- Preparation & Manufacture