Metal-semiconductor nanocontacts: Silicon nanowires

Silicon nanowires assembled from clusters or etched from the bulk, connected to aluminum electrodes and passivated, are studied with large-scale local-density-functional simulations. Shore (similar to 0.6 nm) wires are fully metallized by metal-induced gap states resulting in finite conductance (similar to e(2)/h). For longer wires (similar to 2.5 nm) nanoscale Schottky barriers develop with heights larger than the corresponding bulk value by 40% to 90%. Electric transport requires doping dependent gate voltages with the conductance spectra exhibiting interference resonances due to scattering of ballistic channels by the contacts.