Solar never looked so cool!

Ramesha Perera
Tue 14 May

An international team of scientists has demonstrated for the first time that it's possible to generate a measurable amount of electricity in a diode directly from the coldness of the universe - mind blown! 

New work, in a recent issue of Applied Physics Letters, looks to provide a potential path to generating electricity like solar cells but that can power electronics at night.

The infrared semiconductor device faces the sky and uses the temperature difference between Earth and space to produce the electricity.

"The vastness of the universe is a thermodynamic resource," said Shanhui Fan, an author on the paper. "In terms of optoelectronic physics, there is really this very beautiful symmetry between harvesting incoming radiation and harvesting outgoing radiation."

In contrast to leveraging incoming energy as a normal solar cell would, the negative illumination effect allows electrical energy to be harvested as heat leaves a surface. Though, today's technology doesn't capture the energy differences as efficiently the group was able to find a great enough temperature difference to generate power through an early design.

"The amount of power that we can generate with this experiment, at the moment, is far below what the theoretical limit is," said Masashi Ono, another author on the paper.

While the results show promise for ground-based devices directed to the sky, Fan said the same principle could be used to recover waste heat from machines. For now, he and his group are focusing on improving their device's performance.