Bright visible light emission from graphene

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Bright visible light emission from graphene

Post by Cr6 on Sun Dec 27, 2015 2:53 am


Nature Nanotechnology | Letter

Bright visible light emission from graphene


Nature Nanotechnology 10, 676–681 (2015)
doi:10.1038/nnano.2015.118
Published online
15 June 2015

Graphene and related two-dimensional materials are promising candidates for atomically thin, flexible and transparent optoelectronics1, 2. In particular, the strong light–matter interaction in graphene3 has allowed for the development of state-of-the-art photodetectors4, 5, optical modulators6 and plasmonic devices7. In addition, electrically biased graphene on SiO2 substrates can be used as a low-efficiency emitter in the mid-infrared range8, 9. However, emission in the visible range has remained elusive. Here, we report the observation of bright visible light emission from electrically biased suspended graphene devices. In these devices, heat transport is greatly reduced10. Hot electrons (∼2,800 K) therefore become spatially localized at the centre of the graphene layer, resulting in a 1,000-fold enhancement in thermal radiation efficiency8, 9. Moreover, strong optical interference between the suspended graphene and substrate can be used to tune the emission spectrum. We also demonstrate the scalability of this technique by realizing arrays of chemical-vapour-deposited graphene light emitters. These results pave the way towards the realization of commercially viable large-scale, atomically thin, flexible and transparent light emitters and displays with low operation voltage and graphene-based on-chip ultrafast optical communications.

http://www.nature.com/nnano/journal/v10/n8/full/nnano.2015.118.html

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Re: Bright visible light emission from graphene

Post by Cr6 on Sun Dec 27, 2015 2:59 am

A SpaceCraft built on 2-D:
--------------
https://www.newscientist.com/article/mg22630235.400-spacecraft-built-from-graphene-could-run-on-nothing-but-sunlight/



This Week

27 May 2015
Spacecraft built from graphene could run on nothing but sunlight

Graphene might make solar sails redundant (Image: NASA)

GRAPHENE to the stars. The material with amazing properties has just had another added to the list. It seems these sheets of carbon one atom thick can turn light into action, maybe forming the basis of a fuel-free spacecraft.

Graphene was discovered accidentally by researchers playing with pencils and sticky tape. Its flat structure is very strong and conducts electricity and heat extremely well. Yongsheng Chen of Nankai University in Tianjin, China, and his colleagues have been investigating whether larger arrangements of carbon can retain some of these properties. Earlier this year they published details of a “graphene sponge“, a squidgy material made by fusing crumpled sheets of graphene oxide.

While cutting graphene sponge with a laser, they noticed the light propelled the material forwards. That was odd, because while lasers have been used to shove single molecules around, the sponge was a few centimetres across so should be too large to move.

The team placed pieces of graphene sponge in a vacuum and shot them with lasers of different wavelength and intensity. They were able to push sponge pieces upwards by as much as 40 centimetres. They even got the graphene to move by focusing ordinary sunlight on it with a lens.

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Re: Bright visible light emission from graphene

Post by LongtimeAirman on Sun Dec 27, 2015 12:10 pm

Graphene Sails. That just so happens to be a favorite fantasy of mine. A solar sailing ship. All the sail complexity of the grand old ships, but in a 3-d configuration that might appear similar to an alarmed pine cone. (I always wanted to say that I was an asteroid miner). One atom thick layers certainly cuts down on the weight. No metal required? I wonder how well graphene blocks radiation? What radiation levels penetrate or damages the graphene? What about repair? We should create huge fresnel lenses...  

Thanks Cr6
.

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Re: Bright visible light emission from graphene

Post by Cr6 on Mon Dec 28, 2015 1:44 am

LongtimeAirman wrote:Graphene Sails. That just so happens to be a favorite fantasy of mine. A solar sailing ship. All the sail complexity of the grand old ships, but in a 3-d configuration that might appear similar to an alarmed pine cone. (I always wanted to say that I was an asteroid miner). One atom thick layers certainly cuts down on the weight. No metal required? I wonder how well graphene blocks radiation? What radiation levels penetrate or damages the graphene? What about repair? We should create huge fresnel lenses...  

Thanks Cr6
.

Yeah LTAM, I was thinking the same kind of thing via science of fiction.... your comment.... (I always wanted to say that I was an asteroid miner) made me laugh.

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