Effects of atomistic defects on coherent electron transmission in Si nanowires: Full band calculations

The effects of atomistic imperfections on coherent electron transmission in Si[100] quantum wires a few nanometers wide are investigated using a tight-binding Green function approach. We find a significant suppression in the electron transmission by atomistic imperfections in these extremely narrow wires. Multiple conductance peaks or oscillations can be easily developed by the presence of only several vacancy defects, which can lead to a finite zero-conductance region around the subband edge. Several substitutional defects and surface dangling bonds generally result in decreased, oscillatory conductances with more significant effects found in narrower wires.