Ribbon Growth on Substrate (RGS) — A new approach to high speed growth of silicon ribbons for photovoltaics

Abstract

High-speed silicon ribbon growth offers the potential for substantial reduction of the manufacturing costs of photovoltaics. This paper outlines the new RGS process (RGS = ribbon growth on substrate) for the growth of silicon ribbons using a shaping die on a moving substrate. With pulling speeds in the range of 4–10 m/min, ribbons with a thickness of 250–350 μm and a width of 10 cm have been obtained. Columnar crystallization, grain sizes of the order of the ribbon thickness and up to millimeters, and favorable segragation effects offer the potential for solar cell efficiencies of up to about 10%.