From high-efficiency n-type solar cells to modules exceeding 20% efficiency with aluminum-based cell interconnection

• Published in: Progress in photovoltaics Vol. 21; no. 6; pp. 1354 - 1362
• Main Authors: Merkle, Agnes, Schulte-Huxel, Henning, Blankemeyer, Susanne, Feilhaber, Ilka, Bock, Robert, Steckenreiter, Verena, Kajari-Schroeder, Sarah, Harder, Nils-Peter, Brendel, Rolf
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Bognor Regis Blackwell Publishing Ltd 01.09.2013; Wiley; Wiley Subscription Services, Inc
• Subjects: Al-metallization; Applied sciences; back-junction back-contact solar cell; Energy; Equipments, installations and applications; Exact sciences and technology; high-efficiency; laser microwelding; n-type silicon; Natural energy; Photovoltaic conversion; photovoltaic module; Solar cells. Photoelectrochemical cells; Solar energy; Performance evaluation; Conversion rate; Photovoltaic system; n-type silicon; Transmitter; Metallizing; high-efficiency; Al-metallization; Aluminium; Back contact solar cells; Laser welding; Optimization; back-junction back-contact solar cell; Solar cell; Interconnection; laser microwelding; High efficiency; Photovoltaic array; n type semiconductor; photovoltaic module
• ISSN: 1062-7995; 1099-159X
• DOI: 10.1002/pip.2297

ABSTRACT We present the integrated development of back‐contacted solar cells and an adequate module interconnection for a high‐efficiency photovoltaic module. We report on a large area (125 × 125) mm2 back‐junction back‐contact n‐type solar cell metallized with aluminum having a total area conversion efficiency of 20.7%. To transfer the high conversion efficiency to the module, we use the laser welding process named aluminum‐based mechanical and electrical laser interconnection for module integration of these back‐contacted solar cells. We further analyze the impact of the busbars of our back‐junction back‐contact cells on the cell performance and report on optimization of the cell/module interface. The new cells have an adapted rear‐side geometry by omitting the emitter busbar. A proof‐of‐concept module consisting of these cells is presented. Copyright © 2012 John Wiley & Sons, Ltd. We present the integrated development of back‐contacted solar cells and an adequate module interconnection for a high‐efficiency photovoltaic module. The impact of the busbars of our back‐junction back‐contact cells on the cell performance is analyzed, and we report on optimization of the cell/module interface. As a first step towards modules with busbar‐free cells, we fabricated cells with only one busbar and interconnect them in series.