2023-07-31 16:45:56
Solar panels – CALTECH
MADRID, 31 Jul. (EUROPA PRESS) –
A new device that violates the physical law about the connection between an object’s ability to absorb and emitting energy can revolutionize sustainable energy harvesting systems.
If one takes an object and exposes it to the sun, it will start to heat up. This is because it is absorbing energy from the sun’s rays and converting that energy into heat. If you leave that object outside it will continue to get hot, but only up to a point. After all, a person sunbathing on the beach will not catch fire.
As objects (or people) absorb energy (sunlight), they also give off energy (infrared radiation or heat). This is something you may have experienced walking past a block wall on a summer afternoon and feeling the heat emanating from it.
The connection between an object’s ability to absorb and emit energy in the form of electromagnetic radiation, its absorption and emission efficiencies, has long been explained by something known as the Kirchhoff’s law of thermal radiation. The law, a concept devised by Gustav Kirchhoff in 1860, which states that the absorption and emission efficiencies are equal at each wavelength and angle of incidence.
The new device developed in the lab of Harry Atwater, professor of Applied Physics and Materials Science at Caltech, breaks that normally close relationship between an object’s absorbed and emitted efficiencies.
“Kirchhoff’s law been advocated for over 150 years, and while theoretical proposals for its violation have already been put forward, this is the first experimental proof that this law can be broken,” says Atwater. it’s a statement.
Electrical engineering graduate student Komron Shayegan, lead author of the new research, explains: “Our study shows that it is possible to break the equality of Kirchhoff’s thermal radiation law with a device placed in a moderate magnetic field. The device itself combines a material that has a strong magnetic field response with a patterned structure that improves absorption and emission at infrared wavelengths.What’s particularly exciting is that we can observe the effect simply by heating the device above room temperature and directly comparing the emission efficiency with the absorption efficiency”.
The article describing the work is published in the journal Nature Photonics.
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