In order to generate electricity from the dissipated heat, which would simply fly away into space, rectifying antennas or rectennas are needed.
Scientists have created a rectenna, and in order to collect as much energy as possible, you need to use the smallest element. However, it was necessary to solve the problem of increasing resistance as the elements decrease.
The researchers talked about the element based on the tunnel effect. This means zero resistance to electron transfer and a sharp increase in the level of production. The researchers were able to get this effect after they created a gap between two layers of dielectric between the junction contacts – the so-called quantum well. The selection of the gap and the thickness of the dielectrics was such that the electron tunneled from one contact to another, as if passing through a wall.
Next, the authors tested an array of more than 250,000 butterfly-shaped rectennas made of nickel, nickel oxide, alumina, chromium and gold. They were all about 11 nm long and 6 nm wide. As a result, the design showed conversion efficiency 100-1000 times higher than previous optical rectennas.