Silicon solar cells with low-cost substrates

Patent · Tue Nov 07 04:00:00 EST 1978

OSTI ID:6392665

Kotval, P S; Strock, H B

Epitaxial and diffusion-type planar diodes and solar cells utilize low-cost refined metallurgical silicon substrates having a substantially higher impurity content than conventional high-cost, high purity semiconductor grade silicon. The epitaxial type products have an n-on-p-on-p substrate configuration, while the diffusion-type products have pentavalent impurities diffused therein to form a p-n junction in the low cost silicon substrate. One embodiment employs a multigrained refined metallurgical silicon (RMS) prepared by precipitating essentially iron-free silicon platelets from a solution of metallurgical grade silicon in molten aluminum, melting said refined platelets, in contact with a silica slag and pulling silicon boules from a melt of said refined metallurgical silicon (RMS). By directionally solidifying the refined silicon--slag melt, a multigrained, directionally solidified refined metallurgical silicon (DS/RMS) is obtained, with boules being pulled from a melt thereof for use as said low-cost substrate. The DS/RMS may also be re-melted and directionally solidified a second time with the boules being pulled from said twice directionally solidified material being a desirable, low-cost, single crystal material suitable for use as said substrate for planar diode and solar cell applications.

• Assignee: Union Carbide Corp.
• Patent Number(s): US 4124410
• OSTI ID: 6392665
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
ALUMINIUM
CHALCOGENIDES
CHEMICAL PREPARATION
COST
CRYSTAL GROWTH
DIRECT ENERGY CONVERTERS
ELEMENTS
EPITAXY
FABRICATION
IMPURITIES
METALS
MINERALS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
SEMICONDUCTOR DEVICES
SEMICONDUCTOR DIODES
SEMIMETALS
SILICA
SILICON
SILICON COMPOUNDS
SILICON OXIDES
SILICON SOLAR CELLS
SOLAR CELLS
SUBSTRATES
SYNTHESIS