Of the many possible uses for the one-atom-thick "wonder material" known as graphene, creating something so necessarily visible as a digital display seems particularly fantastical. Because graphene is so thin, it is nearly impossible to see with the naked eye. Yet recent advances in graphene research show that the material may soon be lending its remarkable strength, flexibility and transparency to our digital devices as a key component of their displays.
Scientists have come up with a commercially scalable way to use this essentially invisible material to emit visibly bright light. In doing so, they have made significant strides toward creating flexible and transparent displays for digital devices.
Graphene is already well-known as a key material in creating flexible and transparent electrodes. Researchers now report that they have added light emission to the material's long list of desirable properties, in a paper published in the journal Nature Nanotechnology on June 15.
"This is the first observation of bright visible light emission from one atom thick carbon, graphene," study leader Young Duck Kim of Columbia University told Tech Times. "Here, graphene can be the multifunctional material used for both electrodes and lighting elements."
Combining traditional lighting elements with graphene electrodes has been a major obstacle to the development of flexible and transparent displays. Using graphene itself as the light source eliminates the need to build complex structures for attaching additional light sources to graphene electrodes. This could help to streamline the development of flexible and transparent displays.
"We expect graphene based commercial products such as as graphene lighting – which we can attach the window and wall – within two to three years, and flexible and transparent display modules within five years," said Kim.
The researchers attached tiny strips of graphene to an electronic chip. They then passed electricity through the graphene strips, causing them to heat up to nearly 3,000 degrees Celsius (5,432 degrees Fahrenheit) and emit bright light. It's the same concept that makes the filament inside an incandescent lightbulb glow — leading Kim and his colleagues to dub their creation "the world's thinnest lightbulb."
Traditional lightbulb filaments, often made from a metal called tungsten, don't work so well for this purpose because they melt the chip around them when they heat up. But graphene's special properties allow it to confine the heat to a small area — so graphene filaments don't have this problem.
According to Kim, "quality of graphene is not critical" for this purpose. This, as well of the simplicity of its design, are part of what made it possible for the researchers to demonstrate the scalability of this new technology. Kim and his colleagues are currently working on developing flexible and transparent graphene displays.
