From graphene created the miniature light bulb in the world

The world’s lightest and slimmest light bulb has been manufactured from graphene. This is a form of carbon famous for being stronger than steel and more conductive in nature than copper and now can be used for making bulbs glow. Scientists have created a light-emitting graphene transistor that works much the same way as the filament in a light bulb. This was revealed at a press statement by James Hone, a mechanical engineer from Columbia University, New York. Experts have for long wanted to create a tiny light bulb to place on a chip to create photonic circuits that run on light rather than electric current. The problem is one of size and temperature — incandescent filaments get extremely hot before they produce visible light. This new graphene device is so efficient and tiny that the resulting technology offers new ways to make displays or study high-temperature phenomena at small scales, the researchers said. In the latest study, the scientists used strips of graphene a few microns across and from 6.5 to 14 microns in length. Each strip spanned a trench of silicon like a bridge. (A micron is one-millionth of a meter, where a hair is about 90 microns thick.) An electrode was attached to the ends of each graphene strip and much like tungsten, run a current through graphene and the material lights up. However there is an added twist, as graphene conducts heat less efficiently as temperature increases. This means that the heat stays in a spot in the center rather than being evenly distributed as in a tungsten filament. This miracle material promises to light up the bulbs and is possible since it is transparent and light. Unlike conventional filaments, graphene allows the emission spectrum by changing the distance from the substrate. http://www.thestandarddaily.com/scientists-make-miniature-graphene-light-bulb-for-photonic-circuits/3081/