This technique involves creating a gap of about 1 nm between two metal electrodes, and then using a potential difference to promote electron tunneling through the gap. Wang said that these plasmons are the collective oscillations of electrons in the surface of a metal rod. Light frequency oscillates. When they reach the far end (lower end) of the rod, they are coupled into free space at the frequency of light, becoming photons-light-whose wavelength is directly related to the applied voltage.
"For optical interconnects, this is an alternative to semiconductor lasers," Wang said. "Semiconductor lasers are large and not compatible with CMOS." "Because the size of the parts involved is small, the output light can be rapidly modulated. Most of the tunneling of the gap is elastic, so the luminous efficiency is very low, but the King ’s metamaterial gold rod array provides 100 billion tunnel junctions, which can convert so many electrons into plasmons, so that the emitted light is visible to the naked eye. Light.
Flexible tunnel
Unlike elastic tunneling, elastic tunneling is effective and does not form plasmons. Instead, it generates `` hot '' (high-energy) electrons in the gap. If there are molecules in the gap, these hot electrons can promote chemical reactions, opening the door to scientific and sensing applications.
At the same time, if the amount of intra-elastic tunneling is affected by reactions or molecules, the amount of light emitted at the far end of the rod can be used as a measure of the chemical reaction. Researchers performed oxidation and reduction of oxygen and hydrogen molecules on the device. "The new tunneling technology can produce adjustable and consistent hot electrons, so it can be used to control the high precision of the chemical reaction. The products produced by the chemical reaction at the junction will greatly affect the tunnel performance," Kings College said.
"The material can be modified to make it sensitive to different molecules, making it a sensitive, inexpensive, and easy-to-use sensor that provides visual feedback when a molecule is detected." The vertical brush used by King's team Wang said that the electron-like structure allows multiple gaps to be solved with electrons, or two electrodes and a gap can be used to form a horizontal structure. This work was published in Natural Nanotechnology and was titled Reactive tunnel junction in the material ''.
