Solvent refining of silicon for solar ce

Solvent refinement has been suggested as an energy- and cost-efficient process to produce high purity silicon for photovoltaic solar cells. In this process, metallurgical grade silicon is dissolved in a liquid metal, such as aluminum, at high temperature, allowing for the precipitation of high purity silicon crystals by decreasing the temperature. The study focuses on dissolving metallurgical grade silicon containing iron impurities in liquid aluminum at 1000 °C and extracting silicon crystals slightly above the eutectic temperature. These crystals were treated with hydrochloric acid to remove residual aluminum. The extracted silicon, which exhibited significant amounts of residual Al-Si eutectic, was further processed through oxidation and sedimentation to efficiently eliminate aluminum oxides. Results indicate that careful temperature control, effective leaching procedures, and the use of silicon oxide during remelting are critical for improving the solvent refining method and achieving higher purity levels in silicon suitable for solar cell applications. The transition to photovoltaic energy sources, driven by growing concerns over global warming, underscores the importance of such innovative methods to enhance the production efficiency of solar cell materials.