Feedstock, Crystallization and Wafering

Advancements in silicon materials for photovoltaics are most efficient when achieved throughout the entire production chain. The opportunities afforded by the silicon materials platform established by our team at Fraunhofer ISE in 2011, allow us to model all process steps from mono- and multicrystalline ingot crystallization to block shaping, polishing and wafering. We are thus able to offer skilled, comprehensive characterization of all the different process steps involved from the feedstock through to the finished solar cell under one roof.

Our research aims to develop silicon crystals and silicon wafers for solar cells that are of the highest quality and the lowest cost. In order to achieve this, innovative approaches are adopted in the crystallization process to minimize the introduction of impurities and defects, and processes and equipment are developed for increased throughput. In relation to wafering, we research diamond wire and slurry-based sawing processes for outstanding cutting performance, minimum kerf losses and optimum wafer surfaces.

The high levels of expertise that we employ for the benefit of our clients are demonstrated by multicrystalline wafers manufactured in block casting processes that exhibit solar cell efficiencies of up to 20%, and wafer thicknesses of under 70 µm.