Solar cell with nano-carbon technology converts heat into light, increasing efficiency to 80%

The solar industry breakthrough will allow us to take advantage of the huge energy "falling from the sky".

Technology that turns light into energy is indeed a great achievement for mankind, but sadly we have not optimized it: most of the energy is lost as heat. As a result, the performance of solar panels we often see is only 11-12%.

Obviously, the researchers were startled to see a new solar cell technology that could boost performance by up to 80%.

The new solar cell design disperses heat dispersed in the form of thermal photons carrying ultraviolet radiation.

The new solar cell design uses a series of carbon nanotubes as retaining walls, catching heat dispersed in the form of thermal photons carrying ultraviolet radiation. The device will push that energy in the form of light carrying another wavelength, which can be 'recycled' into electricity.

'Thermal photon particles are still photons, only in that it emanates from a hot object' , explains engineer Jinichiro Kono from Rice University. 'If you use an infrared camera to observe an object with a high temperature, you will see it glow. Having that image is because the camera catches those heat-stimulated photons. '

Infrared radiation is what makes the sun heat. Obviously it is invisible to the naked eye, but its electromagnetic spectrum is similar to radio waves or X-rays. Gas stove, campfire or even a cat lying on your lap emits infrared radiation.

Basically, anything radiating heat will emit infrared radiation.

This is a carbon nanotube with the ability to keep heat photons and reduce their bandwidth, turning them into light to continue generating electricity.

Engineer Gururaj Naik further explained : 'The problem is that heat radiation has broadband , while technology to convert light into electricity is only effective when the source has a narrow bandwidth. The difficulty lies in having to squeeze light-broadband photons that pass through a narrow door. '

The new system differs thanks to the application of a very thin layer of carbon nanotubes, a technology that has been tested by another team in 2016. One of the features that people believe in carbon nanotubes is the electrons inside the tube. can only go in one direction.

The above attribute causes a bipartite dispersion effect (hyberbolic dispersion) , a thin carbon nanorod that will act as a one-way conductor. This means that thermal photons will be able to enter the device from any direction, but only escape in a single way.

Since then, the process of light transformation, then from light, has been converted into electricity.

The team from Rice University successfully fabricated the device to prove the concept.

Carbon nanotubes can withstand temperatures up to 700 degrees Celsius, but this is still not its upper limit: in theory, carbon nanotubes can withstand temperatures up to 1,600 degrees Celsius.

The experiment was initially successful, the system was able to reduce the bandwidth of thermal photons and create light. The next step would be to reuse the light, converting it into electricity.

'By writing all the excess heat into light, we can continue to produce electricity efficiently. According to initial estimates, solar system performance may reach 80%, ' said researcher Naik.

Research has been published on ACS Photonics.