nanoREV.

Suspended Graphene Shows Ballistic Promise

In a recent article posted as an Advance Online Publication of Nature Nanotechnology, researchers from Rutgers provide even more support of graphene’s promise in future nano devices.  The researchers compared electronic properties of suspended graphene (SG) –that is, graphene held between two electrodes and not physically in contact with a substrate–against that of nonsuspended graphene (NSG) in which the devices are formed using conventional layered etching techniques.  The reason for “suspending” graphene over, and not in physical contact with the substrate was to eliminate electronic traps normally found in an oxide or at the interface between graphene and the gate-oxide.  By reducing the trapped-charge density, the researchers increased the free-charge density–and hence sought to increase the carrier mobility.   Hence, they could then study the intrinsic transport properties near the Dirac point, which tends to be a difficult range to measure since charge carrier density virtually disappears (i.e. if there’s normally not enough carriers to measure, how do you measure them?).

The researchers concluded that the experiments provide strong evidence of near ballistic transport (i.e., mainly non-scattered transport), which is a step in the right direction for the use of graphene in future, advanced electronics.