Graphene Semiconductors: Revolutionary Production Of Solar Cells, LED Components (+VIDEO)
Rigid and opaque silicon semiconductors are generally used to make electronics, though marked change may soon occur due to a revolutionary research led by Dr. Helge Weman and Prof. Bjørn-Ove Fimland at the Norwegian University of Science and Technology. Scientists have invented a new method of making semiconductors out of graphene; being one micrometer thick, these semiconductors are highly flexible and transparent. Among the benefits of graphene are high electrical conductivity, it is the thinnest existing material, yet one of the strongest, and besides low-priced to manufacture. Dr. Weman claims that the potential of the invention is tremendous, it might evoke a revolution in the production of solar cells and LED components: Windows could double as solar panels or a TV screen at an average home, mobile phone screens could be wrapped around the wrist like a watch. CrayoNano, a spin-out company, will further develop the technology.
To briefly describe the process of making semiconductors, it starts in a vacuum chamber by “bombing” a graphene substrate with gallium atoms, which stick to the graphene and clump together to form gallium droplets. The gallium atoms naturally arrange themselves on the underside of each droplet, then arsenic molecules are introduced to the graphene sheet. Both arsenic molecules and gallium atoms are absorbed into the existing gallium droplets; once inside a droplet, the arsenic travels to the bottom, where it combines with the gallium atoms and they form into a crystalline structure. The process recurs and the crystals collect to grow into a nanowire, with the droplet perched at the top. After some minutes the hybrid finished product is ready – a graphene substrate covered with an array of one-micrometer-tall gallium/arsenic nanowires, evenly distributed in a hexagonal layout.