Epitaxial silicon growth for solar cells. Quarterly report No. 2

Technical Report · Sat Apr 01 04:00:00 EST 1978

DOI:https://doi.org/10.2172/6642809· OSTI ID:6642809

D'Aiello, R V; Faughnan, B W; Robinson, P H; Richman, D

The objective of this program is to develop and apply epitaxial growth techniques to the fabrication of efficient solar cells on low-cost forms of silicon. Progress is reported. The efficiency of baseline epitaxial solar-cell structures of about 1 mil thickness grown on single-crystal substrates and processed with diffused junctions has been reproducibly established at approximately 13% (AM-1). Experiments were conducted in the growth of the entire cell structure including the junction layer. For baseline cells fabricated on these layers, efficiencies of approximately 10% have been obtained. These structures were grown with junction depths of 0.8 to 1.0 ..mu..m which resulted in sort-circuit current densities of approximately 24 mA/cm. Techniques for the reproducible growth of thinner surface layers are being pursued, in order to increase the short-wavelength response of these structures. Epitaxial techniques were applied in the growth of diagnostic layers and solar-cell structures on two potentially, low-cost, polycrystalline silicon substrates, namely Wacker (SILSO) and a Refined Metallurgical Grade (RMS) silicon. X-ray topographic studies have shown improved crystallographic quality in the epitaxial layers grown on both substrate forms. The best solar cells were fabricated on the RMS substrates where an AM-1 efficiency of 10.6% was obtained with a 16-..mu..m thick epitaxial layer. Epitaxial structures on the Wacker substrates yielded efficiencies in the 5.6 to 9.5% range.

• Research Organization: RCA Labs., Princeton, NJ (USA)
• DOE Contract Number: NAS-7-100-954817
• OSTI ID: 6642809
• Report Number(s): DOE/JPL/954817-2
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
36 MATERIALS SCIENCE
360601 -- Other Materials-- Preparation & Manufacture
COST
CRYSTAL GROWTH
CRYSTALS
DIFFUSION LENGTH
DIRECT ENERGY CONVERTERS
EFFICIENCY
ELECTRICAL PROPERTIES
ELEMENTS
EPITAXY
FABRICATION
PERFORMANCE TESTING
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
POLYCRYSTALS
SEMIMETALS
SILICON
SILICON SOLAR CELLS
SOLAR CELLS
SPECTRAL RESPONSE
SUBSTRATES
TESTING