Cubic SiC preferred over silicon based solar cells

BANGALORE, INDIA: According to Swedish researchers at the Linkoping University, Cubic silicon carbide is considered a perfect material for impurity solar cell. It is capable of collecting more than twice the solar energy than silicon based solar cells.

For boron doped cubic SiC, the dopant band of B in the bandgap of 3C-SiC leads to an efficient use of sun light so that an efficiency up to 48-60 per cent could be achieved depending on theoretical models, reports Julien Happich of EETimes.

As per Mikael Syvajarvi, associate professor at the Linkoping University, cubic silicon carbide has shown to be the black sheep of the silicon carbide family. Cubic silicon carbide are metastable and that seems to the major challenge for cubic silicon carbide. But hexagonal silicon carbide types have been commercialized for many years now. One has to decrease the growth temperature of cubic silicon carbide to make it form, but at the same time the growth rate is decreased. Usually silicon is used as a substrate but the lattice and thermal mismatch causes defects and stress.

Hexagonal substrate provides perfect matching and structural measurements have shown a similar quality like in hexagonal commercial material. Currently, Silicon solar cells have an efficiency of 20 per cent.

Multi-junction solar cells with different bandgaps are one of the best approaches to increase the efficiency of solar cells. The best efficiency of such solar cells demonstrated on the research scale is 43.5 per cent. However, the challenges in fabrication of multi-junction solar cells lie in the growth of multi-stacked material and balance of junction currents.