Scientists at the University of Michigan in Ann Arbor have uncovered a property in light that’s been overlooked for over a hundred years that may allow for solar power without the need for semiconductor-based cells. While it’s long been known that light carries electric and magnetic elements, physicists have dismissed light’s magnetic effects as being too weak to be of any consequence and, subsequently, left them out of the equation while developing the science behind solar power — until now!

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While under normal circumstances, the magnetic field in light is pretty darned weak. However, at just the right intensity and while traveling through a material that doesn’t conduct electricity (such as glass), a light field’s magnetic effects generated can be magnified up to 100 million times stronger than previous calculations have estimated. This results in a charge separation called optical rectification, which can be used for cheaper, more efficient solar power.

Team member Professor Stephen Rand says: “This could lead to a new kind of solar cell without semiconductors and without absorption to produce charge separation. 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.”

While sunlight doesn’t generally shine at the 10 million watts per square centimeter required to amplify its magnetic properties to a significant degree, this discovery paves the way for materials to do so that will be much cheaper than traditional solar cell technology. Says team member William Fisher: “To manufacture modern solar cells, you have to do extensive semiconductor processing. All we would need are lenses to focus the light and a fiber to guide it. Glass works for both. It’s already made in bulk, and it doesn’t require as much processing. Transparent ceramics might be even better.”

The team’s paper detailing this research, Optically-induced charge separation and terahertz emission in unbiased dielectrics, has been published in the recent Journal of Applied Physics.