Local heterostructure contacts

• Main Authors: SCHERFF MAXIMILIAN, FAHRNER WOLFGANG RAINER
• Format: Patent
• Language: English
• Published: 24.12.2009
• Subjects: BASIC ELECTRIC ELEMENTS; CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION ORPROCESSING OF GOODS; 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; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ARTCOLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE

Disclosed is a novel method for creating local contacts in solar cells. In the method, a surface passivation that has been applied to a semiconductor substrate is locally etched away using a plasma process with the help of a thin stretched, elastic foil. If necessary, deep doping gradients are then locally created at the same points by means of a hydrogen plasma treatment with the help of thermal donors so as to increase the diffusion length of the charge carriers in the direction of the contacts. Finally, local heterostructure contacts are applied through the same mask openings. The contacts are characterized by a much lower saturation current than common diffused contacts and are therefore particularly suitable for high-performance solar cells.