What is Graphene? You have surely heard of graphite, so to speak, the one that is at the center of the pencils and allows us to write. This material is a distant relative and finds a wide application in the sector of photovoltaic.
What is Graphene
Two scientists, André Geim and Kostya Novoselov, Nobel Prize in Physics in 2010, by gluing a block of graphite to a normal adhesive tape, have created the thinnest sheet in the world: graphene. In more technical terms, the graphene it is obtained in the laboratory when the graphite crystals are treated with highly acidic solutions and subsequently oxidized and exfoliated to obtain a monatomic layer of carbon atoms hybridized in the sp² form. This is why it is the thinnest sheet in the world, the thickness of graphene is made up of only one layer of atoms!
The characteristics of graphene
The result is an extremely versatile material, consisting of a single layer of carbon atoms arranged in a hexagonal shape at a constant distance between them of 0.142 nanometers. It is a purely two-dimensional crystalline material, it is light, resistant (100 times more than steel), flexible (5 times more than steel), transparent and waterproof. But above all it has great thermal conductivity, electrical and electronic. In this way, graphene is a candidate to replace silicon in new generation electronic materials.
Photovoltaic and Graphene. Graphene could replace Silicon!
Some studies conducted by teams of US researchers have noted that applying graphene to photovoltaic systems an increase in efficiency of 52% can be achieved. In the photovoltaic sector, graphene could replace silicon, a very expensive and close to exhaustion resource: it would involve adding this material to the tungsten dioxide present in solar cells.
Graphene is extractable from commonly used objects such as glass, food and even excrement, it could probably be extracted from any material containing the element carbon. The only problem is the extraction process. We need copper supports and furnaces powered by argon and hydrogen gas at a temperature of 1900 °.
In the process, the extractive material decomposes under the copper sheet, while impurities and waste materials settle above it. In the context of environmental sustainability, graphene proves to be an excellent ally of ecology and at the service of green tecnology.