Edge stabilized ribbon (ESR) growth of silicon for low cost photovoltaics

Abstract The edge stabilized ribbon (ESR) growth method is a shaped crystal growth technique wherein a ribbon is grown from the surface of the melt and the edge positions are determined by capillary attachment to wetted strings which pass up through the melt and are frozen into the ribbon as it grows. The method is compared to other ribbon growth techniques and found to have significant advantages, notably stability of growth and ease of production scale-up. A continuous growth melt replenished furnace has been constructed and run around the clock on a three-shift basis. This single ribbon machine was operated over a run period of 100 h with a duty cycle of 96% resulting in the production of 62,000 cm 2 of ribbon. A panel of 36 series-connected 50 cm 2 ESR solar cells was found to have an AM1 encapsulated cell efficiency of 12.7%. Future work should include reduction of thermal stress and the growth of multiple ribbons.