POLYCRYSTALLINE SILICON FOR SOLAR CELL, AND PROCESS FOR PRODUCTION THEREOF

摘要

The present invention provides a process for preparing a polycrystalline silicon having the surface layer in which the areas having a short carrier lifetime due to Fe has been substantially eliminated. A preparation method of polycrystalline silicon comprising preparing a mold evenly applied with a mold release agent produced by mixing a binder and a solvent with a silicon nitride powder and then solidifying a molten silicon in said mold, wherein x ‰¦ 5.0, 20 ‰¦ y ‰¦ 100 and x × y ‰¦ 100 are satisfied given that x represents a concentration of Fe (atomic ppm) contained as impurity in the silicon nitride powder and y represents a thickness of the mold release agent (µm) applied to the mold.