A research team led by the Australian National University (ANU) has developed a new type of silicon that will optimise sunlight use and reduce the cost of solar technology.

According to senior researcher ANU professor Jodie Bradby, silicon was used as the raw material for solar cells due to its abundance, low cost and non-toxicity.

"But the standard form of silicon does not use all available sunlight," says professor Bradby.

"Just by poking silicon with a tiny hard tip, we've created a more complex silicon capable of absorbing more sunlight than the standard type commonly used in solar cells.

"We have proved that we can easily make this new kind of silicon – previously thought unobtainable under normal room temperature and pressure – which could be used for making more efficient solar cells and lead to cheaper energy."

Dr Sherman Wong, who worked on the study for his PhD at ANU, says the team was exploring a little-known property of silicon – its ability to exist in different crystal forms.

"Silicon can also take many crystal forms that have different and useful properties," he says.

"The new type of silicon we've created is called r8-Si. Instead of the atoms being square or cubic like in standard silicon, it's more complex - shaped a bit like a diamond on playing cards, only it's in 3D.

"It's an exciting field and there is a multi-billion-dollar industry built around silicon manufacturing, so silicon is a super important material that's worth optimising."

Bradby says the team would use unique high-pressure facilities at ANU to develop ways of making enough material to produce a prototype solar cell.

"We now need to measure how well this material absorbs light and behaves electrically," she says.

"We also need to scale up and then work on integrating this material into existing solar industries. This will take another three to five years."

Image: Dr Sherman Wong, who worked on the study. Credit: ANU