Quantum Tunnelling

Source: sciencealert.com

Conventional solar panels only harvest a small amount of the visible light spectrum. The sunlight contains more energy but due to the limitations of the solar cells the remainder of the energy is not harvested. Researchers searching for a way to capture this extraneous energy have come across using quantum tunneling.

Quantum tunneling is where a particle tunnels through a barrier instead of going around the barrier. The Heisenberg Uncertainty Principle explains the working of quantum tunneling by the wave-particle duality of matter.

The researchers designed an antenna that can detect infrared heat as high frequency electromagnetic waves then transforming the waves into electrical charge. They created a a bowtie shaped nanoantenna with a thin insulating film sandwiched in between the metallic arms, see the photo below.

Source: sciencealert.com

The diode the created is a MIM or a metal-insulator-metal. A diode is an one way detector that allows electrons to flow in only one directions. This extracts a DC current from the antenna. The important part of designing the diode is to place the metal a wavelength away from the other piece of metal. If the placement is not a wavelength (of the infrared radiation) the energy transferred will be lessened or if the spacing is too far off, there will be no energy transferred.

With this improved design, solar panels will be able to harness power from not only sunlight but also from infrared radiation so they could collect power 24 hours a day.