Tweaking silicon to improve solar cells for cheaper energy

An international research team led by researchers at The Australian National University (ANU), including ARC Future Fellowship recipient, Professor Jodie Bradby, has made a new type of silicon that better uses sunlight and promises to cut the cost of solar technology.

Silicon is a preferred raw material for solar cells due to its abundance, low cost and non-toxicity, even though the standard form of silicon used in solar cells cannot make use of all the available solar energy.

The researchers discovered that by simply prodding the silicon with a microscopic hard tip, they could change its crystal form into something more efficient. The new type of silicon is called r8-Si. Instead of the atoms being square or cubic, as in standard silicon, they form a complex shape, like a diamond in 3D.

Discovered while exploring a little-known property of silicon—its ability to exist in different crystal forms—the researchers say their world-first invention could help reduce the costs of renewable electricity through more efficient solar cells.

The team is now using a unique high-pressure facility at the ANU to develop ways of making enough material to produce a prototype solar cell, which will enable them to measure exactly how the new silicon absorbs light and behaves electrically.

	“WE NOW NEED TO SCALE UP AND THEN WORK ON INTEGRATING THIS MATERIAL INTO EXISTING SOLAR INDUSTRIES,” SAYS PROFESSOR BRADBY.

 

Image: Dr Sherman Wong worked on the study of the new type of silicon for his PhD at ANU. Credit: ANU.