Aluminosilicates are neutral chemical compounds composed solely of aluminum, silicon and oxygen. They occur naturally as minerals and are used to manufacture corrosion preventative coatings.
Aluminium silicide is a compound of aluminium and silicon that forms through the decomposition of Al2O3 and SiO2. This material has a high melting point and a low coefficient of thermal expansion, which makes it suitable for applications requiring good thermal stability. It can be deposited on a substrate using chemical vapor deposition (CVD) or through sintering of powder mixtures of aluminium and silicon. It can also be incorporated into ceramics, glass and refractory materials.
Despite its promising potential, there is still a great deal of work to be done to make the technology commercially viable. One major hurdle is the cost of manufacturing the amorphous aluminium silicide. Reducing the cost of this material would help to bring solar cells within the price range of many consumers and reduce energy costs for households and businesses.
In order to reduce the cost of silicon, amorphous aluminium silicide was formed from the sintering of powder mixtures of silicon and aluminium. It was then reacted with n-type silicon to form a thin layer of a-phase iron silicide on the surface of the n-Si. This a-FeSi(Al) layer is then subsequently regrown into crystalline silicon, forming an interface that improves the quality of the n-Si/silicon junction.
The a-FeSi(Al)/silicon silicide/n-Si heterostructure was tested for photovoltaic performance. The a-FeSi(Al)/n-Si contact displayed good electrical conductivity and low resistance. Dynamic hysteresis was measured on the Hall bar and found to be similar to that of nickel silicide at a sweep rate of 0.1 T/min.