Transparent Materials Unlock New Possibilities for Photovoltaics
Brian Westenhaus

Some materials are transparent to light of a certain frequency. When such light is shone on them, electrical currents can still be generated, contrary to previous assumptions.

Scientists from Leipzig University and Nanyang Technological University in Singapore have managed to prove this. The scientists have published their findings in the journal Physical Review Letters.

Inti Sodemann Villadiego, Professor at the Institute of Theoretical Physics at Leipzig University commented, “This opens new paradigms for constructing opto-electronic and photovoltaic devices, such as light amplifiers, sensors and solar cells.”

His colleague Li-kun Shi added, “It is possible to drive electric currents by light even when the material has a vanishingly small absorption of such light. This is an important new insight.”

Inti Sodemann Villadiego and his colleagues investigated what are known as “Floquet Fermi liquid” states.

A Fermi liquid is a special state of many quantum mechanical particles with properties that can be very different from those of ordinary classical liquids such as water at ambient temperature.

Fermi liquids can arise in a wide variety of situations, from common materials such as the electrical fluid of electrons in metals like gold or silver, to more exotic situations such as the fluid of Helium-3 atoms at low temperatures.

They can display “spectacular properties,” such as becoming superconductors of electricity at low temperatures.

The “Floquet Fermi liquid” is a variant of this state realized when the particles of the fluid are periodically shaken, such as what happens to electrons in metals when they are illuminated by ideally periodic light.

“In our publication, we explain several properties of these fluid states,” says Professor Sodemann Villadiego. “To study them, we had to develop detailed theoretical models of complex states of electrons shaken by light, which is far from easy.”

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Those new paradigms for constructing opto-electronic and photovoltaic devices have a wide array of possibilities listed. Just where the imaginations of designers and engineers can go with this is without a border today.

The payoff might be sooner than what one might think. Lots of smiles about this and an important journal picked the paper up.

Materials research looks to have a new field opening up!

By Brian Westenhaus via New Energy and Fuel

Brian is the editor of the popular energy technology site New Energy and Fuel. The site’s mission is to inform, stimulate, amuse and abuse the news and views across the emerging field of energy and fuels in our future. You will find the most exciting and useful news, guides and tips for making and saving money in energy and fuel, just how things work or not, where you might want to invest or get involved in a brainstorming session with other readers.

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