Challenges for EFG ribbon technology on the path to large scale manufacturing

Manufacturing processes based on polycrystalline silicon wafers produced by the edge-defined film-fed growth (EFG) technique have reached a mature and competitive status at RWE Schott Solar and a capacity of over 40 MW is now established. EFG ribbon production represents the single largest alternative photovoltaic technology to conventional single crystal polycrystalline silicon wafers produced from ingots of various types, e.g., casting, directional solidification and Czochralski, which currently dominate the industry. Challenges and barriers to continued growth and competitiveness of ribbon technologies are discussed in this paper.