Silicon-on ceramic process. Silicon sheet growth and device developmentt for the Large-Area Silicon Sheet Task of the Low-Cost Solar Array Project. Quarterly report No. 13, October 1-December 31, 1979

Technical Report · Fri Feb 15 00:00:00 EST 1980

DOI:https://doi.org/10.2172/5277156· OSTI ID:5277156

Chapman, P W; Zook, J D; Grung, B L; McHenry, K; Schuldt, S B

Research on 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 reported. The coating methods to be developed are directed toward a minimum-cost process for producing solar cells with a terrestrial conversion efficiency of 11 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 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. Crystal length is limited by the length of the substrate. The thickness of the coating and the size of the crystalline grains are controlled by the temperature of the melt and the rate at which the substrate is withdrawn from the melt. The solar-cell potential of this SOC sheet silicon is promising. To date, solar cells with areas from 1 to 10 cm/sup 2/ have been fabricated from material with an as-grown surface. Conversion efficiencies of about 10 percent with antireflection (AR) coating have been achieved. Such cells typically have open-circuit voltage and short-circuit current densities of 0.55V and 23 mA/cm/sup 2/, respectively.

• Research Organization: Honeywell Corporate Material Sciences Center, Bloomington, MN (USA)
• DOE Contract Number: NAS-7-100-954356
• OSTI ID: 5277156
• Report Number(s): DOE/JPL/954356-79/11
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
SILICON
DIP COATING
CERAMICS
DATA
DIFFUSION
ELECTRICAL PROPERTIES
EQUIPMENT
FABRICATION
GRAPHITE
GRAPHS
IMPURITIES
MULLITE
POLYCRYSTALS
RESEARCH PROGRAMS
SHEETS
SILICON SOLAR CELLS
THERMAL EXPANSION
CARBON
CRYSTALS
DATA FORMS
DEPOSITION
DIRECT ENERGY CONVERTERS
ELEMENTS
EXPANSION
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MINERALS
NONMETALS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
SEMIMETALS
SOLAR CELLS
SOLAR EQUIPMENT
SURFACE COATING
140501* - Solar Energy Conversion- Photovoltaic Conversion
360601 - Other Materials- Preparation & Manufacture