The effect on transport of the boron impurities is strictly related to the details of the (short-range) atomistic potential around the boron dopants. Therefore, an envelope-function approach such as that of References  would not be accurate enough, and more computationally demanding atomistic models are needed. On the other hand, a complete ab-initio simulation of the considered device which includes thousands of atoms would not be numerically feasible. Therefore, for our simulations we adopted a tight-binding model, which is a more simplified approach but preserves atomistic details and is able to correctly reproduce ab-initio results. In our tight-binding scheme we have included only the 2pz atomic orbitals of the carbon and boron atoms, which give rise to the delocalized π molecular orbitals and thus mainly determine the transport properties. In particular, we have used the NanoTCAD ViDES simulation code , which self-consistently solves the transport and electrostatic equations in the device.