Thin-film solar cell and method of manufacturing same

• Main Authors: SICHANUGRIST; PORPONTH, FUJIKAKE; SHINJI, OTA; HIROMITSU
• Format: Patent
• Language: English
• Published: 16.04.1996
• Edition: 6
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGYGENERATION, TRANSMISSION OR DISTRIBUTION; SEMICONDUCTOR DEVICES; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE

Solar cells are formed of (a) a transparent substrate; (b) a transparent electrode; (c) a first doped layer comprising amorphous silicon oxide, optionally including nitrogen, said first doped layer containing a dopant whereby the first doped layer is of a first conductivity type and has an optical gap of from 2.0 to 2.3 eV and a ratio of light conductivity to dark conductivity of 5 or less at 25 DEG C.; (d) a layer of intrinsic amorphous silicon; (e) a second doped layer comprising amorphous silicon, said second doped layer containing a dopant whereby the second doped layer is of a second conductivity type different from the first conductivity type; and (f) a second electrode. The first doped layer may be of either n-type or p-type conductivity. The first doped layer can be formed over the transparent electrode by decomposing a gas mixture comprising SiH4, an oxygen source gas selected from N2O or CO2, and a dopant, in a hydrogen carrier at a substrate temperature of 150 DEG to 250 DEG C., the amount of hydrogen being from 10 to 50 times the amount of SiH4, said first doped layer being of a first conductivity type. An interfacial layer of intermediate gap may also be included when the first doped layer is a p-type layer. Also described is a method for the formation of an amorphous silicon-oxide film to be utilized in making the thin-film solar cell.