We present a semi-analytical model incorporating the effects of edge bond relaxation, the third nearest neighbor
interactions, and edge scattering in graphene nanoribbon fi eld-effect transistors (GNRFETs) with armchair-edge
GNR (AGNR) channels. Unlike carbon nanotubes (CNTs) which do not have edges, the existence of edges in
the AGNRs has a signifi cant effect on the quantum capacitance and ballistic I V characteristics of GNRFETs. For
an AGNR with an index of m=3p, the band gap decreases and the ON current increases whereas for an AGNR
with an index of m=3p+1, the quantum capacitance increases and the ON current decreases. The effect of edge
scattering, which reduces the ON current, is also included in the model.