  It is usually assumed that tunneling current is fairly independent of
temperature. By performing an atomistic transport simulation, we show, to the
contrary, that the subthreshold tunneling current in a graphene nanoribbon
(GNR) band-to-band tunneling transistor (TFET) should show significant and
non-linear temperature dependence. Furthermore, the nature of this
non-linearity changes as a function of source/drain doping and vertical
electric field, indicating that such non-linearity, if properly understood, may
provide important insights into the tunneling phenomena. Finally, by developing
a pseudo-analytical method, we predict that such temperature dependence is not
unique to GNR but should rather be a general behavior for any band-to-band
tunneling transistor independent of the channel material.
