Understanding electron transport in halogenated graphene nanoribbons and possible application as interconnects

Abstract

To analyse the suitability of zigzag graphene nanoribbons (ZGNRs) as interconnects, the influence of halogen (F, Cl, Br, and I) passivation on ZGNRs has been analysed in terms of structural stability, electron transport, and thermal conductivity, as well as the performance parameters of the interconnects. The computation is performed using first-principle density functional theory with a non-equilibrium Green’s function approach, while the performance parameters of the interconnects such as delay and power delay product are computed using a HSPICE simulator tool. The formation energy analysis confirms the stability trend for halogen-passivated ZGNRs as F > Cl > Br > I. With moderate stability, the I- and Br-passivated ZGNRs have relatively better current–voltage characteristics in comparison to F and Cl. However, the Cl-passivated ZGNRs have relatively better interconnect parameters in comparison to other proposed halogenated systems (one edge and both edges), measured in terms of kinetic inductance and quantum capacitance. Another requirement of any good interconnect is less delay and less average power, which have also been computed and found to be relatively better in the case of Cl-passivated ZGNRs. Thus, among the halogen-passivated GNRs tested, those that are Cl-passivated defend their selection for interconnect applications well.