NEDO and Kyoto University Find New High Purity Si Production Method

New Energy & Industrial Technology Development Organization (NEDO) and Kyoto University co-announced on Thursday they developed a new method to produce high purity silicon for solar cells at relatively low cost by utilization of high purity silica. They gained high purity silicon by electrolytic reduction of high purity silica in molten salt. The obtained silicon contained some metal impurities but less phosphorus and boron those which are difficult to be removed. NEDO and Kyoto University announced they can achieve the high purity to be used for solar cells by a method called unidirectional solidification.

Supply of high purity silicon is globally tightening with sharp expansion of solar cell production. The material is gained from productive processes of semiconductor silicon. However, the cost reduction is difficult by this method. The new method by NEDO and Kyoto University enables enough purity and low cost.