20%-Efficient Rear Side Passivated Solar Cells in Pilot Series Designed for Conventional Module Assembling

In the Reiner Lemoine Research Line at Q-Cells a pilot series fabrication of double-side contacted mono-crystalline solar cells using a dielectric passivated rear side with local metal contacts was implemented. A few hundred of such large area (156 mm x 156 mm) high efficiency solar cells were fabricated on boron doped Cz silicon material per week. Median efficiencies of up to 20% before light-induced degradation are reached. The best large area solar cell has an efficiency of 20.2% after deactivation the light induced degradation due to the boron-oxygen complex. The efficiency is independently confirmed by Fraunhofer ISE and demonstrates the high potential of this cell structure even under production like conditions. The R&D cell development of the passivated rear side was supported by a cooperation work with Fraunhofer ISE. In this paper we present R&D results of the cooperation work with Fraunhofer ISE and Q-Cells continuous technical improvements of the mono-crystalline solar cell process in the pilot series fabrication, which also included testing of quality and reliability of these R&D cells integrated into modules