Polysilicon is the feedstock for the solar and semiconductor industries. Solar-grade polysilicon typically has purity levels of 6N (99.9999% pure) to 8N (99.999999%) and it is used to make solar cells; 9N (99.9999999%) polysilicon may also be used in some premium solar cells. Electronic-grade polysilicon has higher purity levels of 9N (99.9999999%) to 11N (99.999999999%) for producing silicon chips/wafer.
The Siemens process is the most widely used method for polysilicon production.
Polysilicon sits on top of the photovoltaic supply chain. It is derived from metallurgical-grade silicon via chemical processes.
One megawatt of photovoltaic power requires seven tonnes, or 7,000kg, of polysilicon material.
Product applications: Solar wafer, solar cell, solar panel/solar module (silicon module, thin film)
Product specifications in the market and which grade(s) ICIS reports on: 6N to 9N (see table below on standard specification in the leading China market)
To find out more Solar Grade Polysilicon Methodology September 2013