Connect with us

Hi, what are you looking for?

CleanTechnica

Clean Power

Graphene Breakthrough — One Photon Can Be Converted Into Multiple Electrons

A new discovery by researchers at the ICFO has revealed that graphene is even more efficient at converting light into electricity than previously known. Graphene is capable of converting a single photon of light into multiple electrons able to drive electric current. The discovery is an important one for next-generation solar cells, as well as other light-detecting and light-harvesting technologies.

20130224-235717.jpg

A paradigm shift in the materials industry is likely within the near-future as a variety of unique materials replaces those that we commonly use today, such as plastics. Among these new materials, graphene stands out. The single-atom-thick sheet of pure carbon has an enormous number of potential applications across a variety of fields. Its potential use in high-efficiency, flexible, and transparent solar cells is among the potential applications. Some of the other most discussed applications include: foldable batteries/cellphones/computers, extremely thin computers/displays, desalination and water purification technology, fuel distillation, integrated circuits, single-molecule gas sensors, etc.

“In most materials, one absorbed photon generates one electron, but in the case of graphene, we have seen that one absorbed photon is able to produce many excited electrons, and therefore generate larger electrical signals,” says Frank Koppens, group leader at ICFO.


 
This ability makes graphene extremely appealing for any technology that requires the conversion of light into electricity, particularly because it allows the development of light detectors with improved efficiency, and should lead to solar cells that are able to capture light energy from all of the solar spectrum with lower loss.

The discovery was made during an experiment that consisted of sending an exact quantity of photons possessing different energies (different colors) onto a monolayer of graphene. “We have seen that high energy photons (e.g. violet) are converted into a larger number of excited electrons than low energy photons (e.g. infrared). The observed relation between the photon energy and the number of generated excited electrons shows that graphene converts light into electricity with very high efficiency. Even though it was already speculated that graphene holds potential for light-to-electricity conversion, it now turns out that it is even more suitable than expected!” says KJ Tielrooij, a researcher at ICFO.

There are some issues with graphene that need to be resolved before they can be used for ‘direct applications’ though. But once these are resolved, graphene holds a revolutionary potential, especially with regards to technologies currently based on conventional semiconductors. “It was known that graphene is able to absorb a very large spectrum of light colors. However now we know that once the material has absorbed light, the energy conversion efficiency is very high. Our next challenge will be to find ways of extracting the electrical current and enhance the absorption of graphene. Then we will be able to design graphene devices that detect light more efficiently and could potentially even lead to more efficient solar cells,” Koppens says in conclusion.

The new discovery was made by researchers at the Institute of Photonic Science (ICFO), in collaboration with researchers at the Massachusetts Institute of Technology, Max Planck Institute for Polymer Research in Germany, and Graphenea S.L. Donostia-San Sebastian in Spain.

The new research was just published in the journal Nature Physics.

Source: ICFO-The Institute of Photonics Sciences
Image Credit: Graphene via Wikimedia Commons

 
 
Appreciate CleanTechnica’s originality and cleantech news coverage? Consider becoming a CleanTechnica Member, Supporter, Technician, or Ambassador — or a patron on Patreon.
 
Have a tip for CleanTechnica, want to advertise, or want to suggest a guest for our CleanTech Talk podcast? Contact us here.

Advertisement
 
Written By

James Ayre's background is predominantly in geopolitics and history, but he has an obsessive interest in pretty much everything. After an early life spent in the Imperial Free City of Dortmund, James followed the river Ruhr to Cofbuokheim, where he attended the University of Astnide. And where he also briefly considered entering the coal mining business. He currently writes for a living, on a broad variety of subjects, ranging from science, to politics, to military history, to renewable energy.

Comments

You May Also Like

Batteries

Tiny Luxembourg aims to dominate the graphene nanotube market for next-generation EV batteries and other sustainable tech.

Clean Power

Brothers in Rice lab find audio from graphene production contains valuable data Originally published on Rice University, Rice News. By Mike Williams It may...

Cars

The race is on to build the solar-powered Evs of the future, and it looks like graphene and TMDs could get the ball rolling.

Batteries

An Australian company says it is testing an aluminum-ion battery that charges faster and stores more energy than any lithium-ion battery. But is that...

Copyright © 2021 CleanTechnica. The content produced by this site is for entertainment purposes only. Opinions and comments published on this site may not be sanctioned by and do not necessarily represent the views of CleanTechnica, its owners, sponsors, affiliates, or subsidiaries.