Recent Patenting Activities in Low-Cost Silicon Raw Materials for Silicon Solar Cells

For the last decades, numerous researches and patents are focused on developing novel refining processes of low-cost silicon. In this paper, patents that reveal different refining methods including chemical routes, metallurgical routes and other promising routes are reviewed respectively, and the detailed processes together with their pros and cons are demonstrated according to their basic principles. Based on different processes used for silicon production, the corresponding techniques of fabricating silicon ingots and solar cells are also introduced.