Tag Archives: Solar power

Surprising effect of light could change solar power generation

Professor Stephen Rand. Image from the University of Michigan

The University of Michigan has announced that researchers have discovered a surprising magnetic effect of light that could lead to solar power generation that doesn’t require the traditional semiconductor-based solar cells.

Stephen Rand, a professor in the departments of Electrical Engineering and Computer Science, Physics and Applied Physics and an author of a paper on the work, said the researchers had found a way to make an “optical battery.” This overturns a century-old tenet of physics.

Light has both electric and magnetic components. Until now, researchers thought the effects of the magnetic field were so weak that they could be ignored. But Rand and his colleagues discovered that, at the right intensity and when light is traveling through a non-conductive material, a magnetic effect can be generated that is 100 million times stronger than previously expected. This is equivalent to a strong electric effect.

“This could lead to a new kind of solar cell without semiconductors and without absorption to produce charge separation,” Rand said. “In solar cells, the light goes into a material, gets absorbed and creates heat. Here, we expect to have a very low heat load. Instead of the light being absorbed, energy is stored in the magnetic moment. Intense magnetization can be induced by intense light and then it is ultimately capable of providing a capacitive power source.”

This new technique could make solar power cheaper, the researchers say. They predict that with improved materials they could achieve 10 percent efficiency in converting solar power to useable energy. That’s equivalent to today’s commercial-grade solar cells.

The paper is titled “Optically-induced charge separation and terahertz emission in unbiased dielectrics” and has been published in the Journal of Applied Physics. You can read the University’s press release on their website.