American researchers discover how to create pure Graphene
US researchers who worked on ways of making electrical contacts on graphene made two important discoveries in the process. Through use of a novel fabrication technique they have managed to create stacked layers of the finest quality of pure graphene yet. Simultaneously, they have managed to make electrical contact only along graphene’s one dimensional edge, thereby increasing the electron injection efficiently into graphene.
The two-dimensional structure of graphene makes it easy to contaminate, thus most of the techniques used when stacking the material within insulating material layers use specified polymers when picking and placing the sheets. The polymers are chemically sticky and rarely contaminate grapheme, thus enabling it to maintain its qualities. The research has disproved the theory that graphene’s ability to conduct would work far more efficiently was it to be confined to the edge of the sheets.
A team of Columbia University researchers headed by Cory Dean has appropriately addressed these problems. This was done by developing a process to create several layers of pure graphene encapsulated by several layers of boron nitride without involving extraneous materials. This was later on followed by exposing graphene’s edges to enable electrical contact.
On completing the assembly, a mask can be then be placed on the surface on top of this, and the sides are plasma edged away so as to expose the single dimension edges of the filling made of graphene. If there is need for electrical contact, the design provides that metals are deposited on the exposed edges.
Studies conducted further entailed research show one could efficiently inject electrons into the single dimension edge, and the studies have also proved electrons can fluently flow through the samples as long as the temperature is slow enough. Dean further argues this process can work well with a number of other two dimensional materials including the transitional metal dichalcogenides.