Advanced Solar-Grade Si Material

Abstract

For three decades scientists around the world have been searching for the right technology to produce silicon feedstock for the photovoltaic industry, feedstock that fulfills the need for “low cost” as well as the need for sufficient quality. The urgency of this task has intensified since 1998, when it became clear that the PV demand could no longer be met with by-products from the electronics industry. The established producers of polysilicon developed specific products for the solar industry, but for the time being cannot catch up with the exploding demand. The actual Si shortage resulted in very high spot prices for solar-grade silicon and led to discussions on whether existing producers with their production methods will be able to cover the future demand of the solar industry. There are, again, opinions being expressed that alternative production methods are more suitable to fill the gap at lower costs. Here, requirements and possibilities have to be checked very carefully. In addition, old knowledge and experience about the different possibilities to produce silicon should not be forgotten. The future supply of silicon to the PV industry has to be seen in the tense environment of quality, costs and time of implementation.