Slashing solar cost

Artificially changing the optical properties of materials to allow light to be trapped in solar cells could possibly reduce the cost of solar energy.

That’s what researchers at the School of Electronics and Computer Science (ECS) at the University of Southampton will be trying to find out in a £4.5 million project which is funded by the Engineering and Physical Sciences Research Council (EPSRC).

‘By creating diffractive nanostructured arrays of gratings on the surface of solar cells using deep sub-micron lithography, optical asymmetries are created that prevent light from escaping,’ explained Dr. Darren Bagnall, of the School of Electronics and Computer Science.

‘And because the new process will allow light to be trapped more effectively, it may allow the efficiency of a solar cell to be increased by 2%,’ he added.

According to Dr. Bagnall, the light-trapping technologies could also reduce the thickness of semiconductor materials needed in solar panels, and this would directly reduce the manufacturing cost too.

The first challenge, however, is to prove that the technology works in practice, the second to develop cost effective ways to produce nanopatterned layers.

‘We have already shown that we can use arrays of chiral nanostructures to change the polarisation of light, now we want to apply the same technology to photovoltaics,’ Dr. Bagnall said.

Other university partners in the project are Durham, Bangor, Northumbria, Bath and Loughborough.