A joint research group led by Professor Masahiro Nomura has succeeded in doubling the thermal radiation from a silicon film by only slightly oxidizing its surface. By slightly oxidizing the surface of the silicon film, lattice vibrations at the oxide film interface thermally excite a coupled wave of light and lattice vibrations called surface phonon polariton, which doubles the thermal radiation from the silicon film. This study overturns the conventional theory that thermal radiation exceeding Planck’s law of thermal radiation cannot be obtained unless the dielectric film is thinned to several tens of nanometers, and shows that even a semiconductor with a strong and easy-to-handle support structure can dissipate heat to the space more efficiently. The research was conducted in collaboration with CNRS, and the resulting paper was published in the online edition of Physical Review Letters on May 3.
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