A theoretical model was introduced for the investigation of scattering by defects in semiconducting C nano-ribbons. The analysis of multichannel coherent transport in the presence of discontinuities was performed by means of a numerical solver, which had previously been shown to predict correctly the electronic properties of C nanotubes, in some respects analogous to the nano-ribbon. A scattering-matrix representation was used to characterize the propagation and scattering of the periodic wave functions of carriers travelling along the C nano-ribbon. Results show that reflection of charge was important for the defect types considered, i.e., atomic vacancy, potential deformation, and discontinuity caused by a 120° bifurcation. Reflection may be enhanced by interaction (resonance) between successive or periodic discontinuities. The dependence of scattering on carrier energy, referred to the band edge, has also been investigated: Generally, reflection decreased as carrier energy increased. The analysis suggests that the operation of devices employing C nanoribbons may be quite affected by the presence of lattice defects.

Coherent Carrier Transport and Scattering by Lattice Defects in Single- and Multibranch Carbon Nanoribbons. D.Mencarelli, T.Rozzi, L.Pierantoni: Physical Review B, 2008, 77[19], 195435 (11pp)