Polycrystalline Silicon, also called Polysilicon or Poly-Si, is a high purity, polycrystalline
form of silicon, used as a raw material for both the photovoltaic (9N: 99.9999999%)
and electronics (11N: 99.999999999%) industries.
Crystalline silicon-based PV manufacturing value chain starts with the processing of quartz sand to produce metallurgical-grade silicon (MG-Si). MG-Si is further purified to Polysilicon feedstock. Polysilicon then is then formed into ingots through a crystallization process. Ingots are sliced into wafers and manufactured into solar cells through a multistep manufacturing process.
Around 25 - 30% of the cost of a crystalline PV module is for polysilicon. About 7 to 5 tons of polysilicon is required to manufacture 1 megawatt (MW) of conventional solar modules.