Abstract:
In this paper, the effect of alkali metal, Li, as
substitutional doping in armchair Graphene Nanoribbons
(AGNRs) is investigated. Electronic and transport properties and
structural stability of Li-doped AGNRs are investigated using
density functional theory (DFT) and non-equilibrium Green’s
function (NEGF). First principle calculations have been
performed on pristine (undoped), center Li-doped, one-edge Literminated and both-edge Li-terminated AGNRs. Our
calculations reveal that all the structures analyzed are
thermodynamically stable. Based on transmission spectrum and
standard two-probe setup based I-V characteristics of all the
considered configurations, center Li-doped AGNRs are found to
be the most suitable candidate for on-chip interconnect
applications. For center Li-doped AGNRs, kinetic inductance, !,
and quantum capacitance, , are extracted as 12.51 nH/µm and
2.7 fF/µm, respectively, which results in nearly 7x, 2.5x and 1.1x
higher current as compared to pristine, one-edge Li-terminated
and both-edge Li-terminated AGNRs, respectively. We have also
compared our results with center Fe-doped AGNRs, where center
Li-doped AGNRs provide 1.71x higher current. Our study
suggests about the substitutional doping of Li at the center in
AGNRs make it an excellent metal that can be used in advanced
nanoscale interconnect applications. In addition, this study can be
extended towards the use of multiple layers of center Li-doped
AGNRs in future that may further improve the interconnect
performance
