New advances in metallurgical solar grade silicon based on recent Norwegian research activities

Among the new routes for the production of solar grade silicon, the metallurgical refining leading to upgraded metallurgical grade (UMG) silicon emerge as serious alternatives to replace the feedstock produced by the Siemens process (commonly called polysilicon). Most of these new alternative processes generally consist of a sequence of purification steps. The most effective and frequently used among these refining steps will be described. Some recent results based on research studies carried out in Norway will be presented with more details. The intention is to give an overview and an understanding of these emerging processes and provide some tools to optimize and further develop new cost efficient processes for production of solar grade silicon (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)