Photovoltaics
Photovoltaic solar cells are devices which can convert sunlight directly into usable electricity. Most common photovoltaic cells can be found on everyday devices such as calculators and wrist watches. PV cells however can be made of complex systems capable of powering buildings and supplementing a power grid.
Technologies
Currently the leading material available on the market is a substance known as crystalline silicon (c-Si), and is used in several forms:
Single-crystalline or monocrystalline silicon
Multicrystalline or polycrystalline silicon
Ribbon and sheet silicon
Thin-layer silicon.
There are several methods in which crystalline silicone is produced. These methods are:
Czochralski (CZ) method
Float-zone (FZ) method
Casting method
Die or wire pulling
Whatever the technique the most important process of manufacturing is the removal of impurities and defects within the silicone. This is usually done by chemically heating the silicone and diffusing the impurities from the silicone. As there is more demand for solar-grade silicone so is the concern for its availability. New innovations are currently being developed but not perfected yet. These technologies include the emitter wrap-through cell and the self-aligned selective-emitter cell.
