By Ralf Preu, Head of the Department for PV Production Technology and Quality Assurance, Fraunhofer ISE; Andreas Wolf, Head of the Thermal Processes/Passivated Solar Cells, Fraunhofer ISE; Marc Hofmann, Head of the Plasma Technology and Surface Passivated Solar Cells Team, Fraunhofer ISE; Florian Clement, Head of the MW T Solar Cells and Thick-Film Technology Team, Fraunhofer ISE; Jan Nekarda, Head of the Laser and PVD Technologies/ Technology Assessment, Fraunhofer ISE; Jochen Rentsch, Head of the Wet Chemical and Plasma Technologies/Cell Process Transfer Group, Fraunhofer ISE; Daniel Biro, Head of the High Temperature and Printing Technologies/Industrial Cell Structures, Fraunhofer ISE
In today’s market, crystalline silicon wafer technology dominates industrial solar cell production. Common devices feature opposing electrodes that are situated at the front and rear surface of the wafer and subsequent front-to-rear interconnection is used for module assembly. This paper reflects the functions which have to be fulfilled for the back-side contact of the solar cell as well as challenges and advances for the two basic classes: full-area and local rear contact formation. While full-area contacting has proven to be a reliable technology for industrial production, local contacting through dielectric layers has yet to be put through its paces in industrial implementation.
