Did you know that the amount of sunlight that hits the earth every 40 minutes is enough to meet the energy demands for a year? One way this can be done is by harnessing the sunlight and applying graphene energy conversion.
A study shows that graphene, with a little tweaking, can produce two electrons from a photon of light that it receives. This study was published in Nano Letters, and Marco Grioni from the Ecole Polytechnique Federale de Lausanne, in Switzerland, is one of the senior authors.
Graphene energy conversion to open up new possibilities
So what is graphene? It is a monolayer of carbon atoms which are arranged in a honeycomb pattern. Its features include durability, exponentially stronger than steel, very light, flexible, and it is capable of conducting electricity better than copper. To ensure that graphene is going to be practicable in any photovoltaic item it would potentially be paired with, the researchers needed to find a way to fully understand how the graphene energy conversion works, especially since converting light to electricity happens in a quarter of a second, or what is called femto-second.
The researchers managed to achieve graphene energy conversion by running it through trARPES. This means the graphene went through a treatment called traARPES, which means ultrafast time and angle resolved photoemission spectroscopy. Using an ultra high vacuum chamber, graphene received a strong blast of ultrafast laser light. The light then elicited an ‘excitement’ from the electrons making them more ‘able’ in carrying an electric current. Another laser light was flashed and this recorded the current level of energy for each electron, for each pulse. The whole series of actions were put together property recording what transpires during the conversion.
Use of graphene energy conversion to significantly improve efficency
‘Doping the graphene’ was done, wherein graphene’s photovoltaic ability to alter the number of electrons chemically was enhanced, making sure to ‘excite’ it, doing the graphene energy conversion. As soon as the photon is received, creating an electron back to the ground state, the other electron is going to ‘excite’ another two more, thus creating electricity.
“This indicates that a photovoltaic device using doped graphene could show significant efficiency in converting light to electricity,” as stated by Grioni.
New graphene technology also comes with limitations still to be resolved
Although doped graphene has its benefits in releasing the electrons, thereby using the extra energy to excite other electrons, it also has its flaws. Because it needs help in absorbing light, when it is going to be used with photovoltaic items, it would have to be combined with other ultra thin materials like, molybdenum disulphide or another ultra thin material, tungsten diselenide. Studies and attempts are currently on going. Once results are confirmed, this will definitely mark a leap from 32 percent of solar energy conversion to 60 percent.
Sunlight to solar energy to electricity that we can use is an astonishing idea to begin with, but with scientists and researchers experimenting and coming up with innovative ideas, we are certainly going our best to make the world better with the natural sources we have.
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Photo by: CORE-Materials on Flickr