Published on : Jan 28, 2015
A research team from 3 U.S. based universities has demonstrated and explained a method to vary the number of electrons in a certain region or area of a piece/chunk of graphene. The team states that this is a proof of principle in the development of semiconductor devices that consist of the so called 'wonder material'. The research group also explains that the number of electrons can be easily be tuned via the application of an electric field and this as a result, could ensure that the future devices can be 'rewired' dynamically.
The research was carried out at the University of Pennsylvania, University of Illinois at Urbana-Champaign, and the University of California, Berkeley. A researcher from the University of Pennsylvania stated that they have developed a non destructive, and a reversible technique of doping that will not bring about any physical changes and alterations in graphene. The method basically involved the deposition of a layer of graphene so that it can rest on, but does not bond to, a lithium niobate layer.
Lithium niobate is primarily ferroelectric, which means that it is polar, and its surfaces either possess a negative or a positive charge. In fact, the application of an electric field pulse can immediately alter the sign of the surface charges. The researchers had basically taken advantage of the fact that a periodically poled lithium niobate, a special type of the material, that is produced for it to have 'stripes' of polar regions that have the capacity to alternate between negative and positive. Lithium Niobate domains have the capacity to govern the properties. This basically means that the different areas of graphene can exhibit different characteristics which actually depend on the properties of the domain underneath.