Silicon ribbon growth using electron bombardment

A method for the production of polysilicon ribbons for solar energy conversion from powder as starting material has been developed. It is based upon the use of an electron beam which, while creating a mobile molten zone on the small grained polycrystalline ribbons, induces the crystallization. These ’’preribbons’’ can be produced directly from silicon powder with the same apparatus. This method is particularly economical because (1) electron beam was used as a means of crystallization (very high energy deposition rate) and (2) as a result of two purification processes peculiar to the method (purification by zone melting and vacuum evaporation), the use of silicon powder of low purity could be envisaged.