Silicon ribbons for solar cells grown from powder by the SSP method

The design of a machine for semicontinuous production of 100-mm wide silicon ribbons is presented. As the grain selection takes place at the beginning of zone melting, continuous processing instead of single-sheet processing is reasonable and leads to fairly wide grains (on the order of 10-20 mm) extending over the whole length of the ribbon. Grain structure and defects are revealed by etching techniques. Due to the high intragrain defect density there is a significant effect of hydrogen passivation which is demonstrated by EBIC and LBIC measurements. The best solar cells made from silicon sheets from powder (SSP) material showed efficiencies above 13%.