Improved Performance of Tunneling FET Based on Hetero Graphene Nanoribbons

A heterojunction tunneling field effect transistor based on armchair graphene nanoribbons is proposed and studied using ballistic quantum transport simulation based on 3D real space nonequilibrium Green's function formalism. By using low band gap nanoribbons as the source/drain material, the hetero- structure shows better performance including higher on current, lower off current, and improved steep subthreshold swings compared with homostructure. It is also found the device performance greatly depends on the source/drain dopping density. High doping density leads to fewer density states in the source and degrades the device performance.