This Small Business Innovation Research Phase I project proposes an innovative method for one-step silicon wafer production for the photovoltaic (PV) industry. Starting directly from metallurgical grade silicon (MGSi), it is proposed to use molten metal as the purification media. MGSi with its impurities will be dissolved in the molten metal, which will separate the impurities from MGSi through the impurity partitioning effect. By manipulating the temperature, and taking advantage of the density difference, silicon can be separated from the molten bath. Once the impurities are separated, silicon wafers will be drawn out from the molten bath. This one-step method eliminates the use of chlorosilanes (normally used to produce polysilicon). In addition, eliminates the steps of crystal growth and wafer slicing for the photovoltaic industry. This process will meet the demands of PV industry to produce inexpensive solar wafers. Phase I of the project will concentrate on the experimental and theoretical research for purification and characterization aspects of MGSi. This will lead to a preliminary design of a one-step wafer manufacturing system. During Phase II detailed research will demonstrate how this single step process can be reduced to practice, leading to commercialization in Phase III. This project will lead to a new US-based technology for the photovoltaic (PV) industry. The proposed technology can substantially reduce the cost of silicon wafers that the PV industry uses. It is expected that with this technique, it will be possible to decrease the cost/watt of solar power into the range in which solar power can become competitive with standard utility power.
