Materials of Solar Cells

This chapter shows the current supply chain of the solar-grade silicon material. The silicon demand of solar cells has rapidly grown, which has become the main force for the global silicon market growth. Before 2002, the solar-grade polycrystalline silicon was mainly supplied from the scraped and rejected products of the semiconductor electronic-grade polycrystalline and monocrystalline silicon. Since the proportion of silicon used by the photovoltaic (PV) industry has been gradually increased, some quality electronic-grade polycrystalline silicon must be used. And the casting polycrystalline silicon has been widely used to the newly-built solar cells and material product lines since then, especially after 1990s. Most of the monocrystalline silicon solar cells adopt the silicon grown by CZ method as the raw material. Accordingly, the absorption layer of the a-Si thin-film cells is only one percentage of the crystalline silicon solar cells in terms of thickness.