High efficiency solar cells on direct kerfless 156 mm mono crystalline Si wafers by high throughput epitaxial growth

This paper demonstrates the Direct Gas to Wafer™ technology to produce high quality epitaxial kerfless mono crystalline n-type and p-type silicon wafers. The key aspects of the approach involve anodic etching to form porous Si release layer, growing epitaxial wafers, separation of the epitaxial wafers from the substrate and substrate reuse. The advantages of epitaxial wafers over conventional Cz wafers are discussed. With 156 mm epitaxial wafers, p-type PERC cell has achieved an efficiency of 19.7% and n-type cell has achieved an efficiency above 20%.