Design And Electrical Properties Research Of Graphene Nano-devices

Graphene is a two-dimensional material. It is rapidly becoming the research focus of thescientific community because of its unique performance of electrical, mechanical and optical. Forthe unique electrical properties and easy-tailoring features, graphene is an ideal material fornano-electronic devices in post-silicon era.In this paper, in the tight-binding approximation model, based on non-equilibrium Greenfunction formalism (NEGF), the electronic transport properties of some graphene-nanoribbon-basednanostructures are computed. We study the electrical properties of transistor with a channel ofarmchair graphene nanoribbon. The research work explores physical insights of electron transportmechanism in graphene-nanoribbon field-effect transistors (GNRFET) and can be some guidelinesfor the improvement of its performance.Firstly, based on theory of graphene and graphene nano-ribbon, research GNRFET’s transportproperties effects, found that the wider ribbon width, the weaker gate control ability of the device.Secondly, a parallel AGNR structure is proposed, by compute and analyze for its conductancecharacteristics, we found: with the increase in the ribbon number, there will be a correspondingincrease number of conductance peaks in the conductance structure, so conductivity switchfrequence with the Fermi potential is faster. With the increase of the spacing between the ribbons,the width of center region is narrower, the two edges in vertical direction is steeper, making it morequickly switching converter.Thirdly, dual-material heterogeneity gate GNRFET is proposed. Researches show that it hasbetter sub-threshold characteristics and bigger current switch ratio than single-material gate devices,when work function of gate material close to the source is larger than that of gate material near thedrain gate, the better sub-threshold characteristics in the device.Finally, triple-material heterogeneity gate GNRFET device is proposed. Researches show that,with different metal materials which have same work function difference as gate, it has bettersub-threshold characteristics and bigger current switch ratio than dual-material heterogeneity gateGNRFET device.