New Type Of Silicon Promises Cheaper Solar Technology
An international research team led by The Australian
National University (ANU) has made a new type of silicon that better uses
sunlight and promises to cut the cost of solar technology.
The researchers say their world-first invention could help
reduce the costs of renewable electricity below that of existing coal power
stations, as well as lead to more efficient solar cells.
Senior researcher ANU Professor Jodie Bradby said silicon
was used as the raw material for solar cells because of its abundance, low-cost
"But the standard form of silicon does not use all
available sunlight," Professor Bradby said.
"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,
is the first author of the paper published in the journal Physical Review
He said 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," said Dr Wong, who is now at RMIT
"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."
Professor Bradby said 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 said.
"We also need to scale up and then work on integrating
this material into existing solar industries. This will take another three to
The shape and complexity of the r8-Si was measured using
X-ray diffraction at the Advanced Photon Source in the United States. The study
was conducted with a large group of colleagues at the University of Melbourne
and several overseas organisations.