Conductance modulation of Si nanowire arrays

The conductance modulation of vertically aligned Si nanowire arrays with ammonia is investigated. Ammonia adsorption on the surface of the nanowires (NWs) in the array greatly increases the electrical conductivity of n-type NWs. This effect can be potentially applied to boost figure of merit for thermoelectric applications by combining the phonon confinement effect of NWs with the electrical conductivity increase. By using 1/f noise measurements, the mechanism of conduction modulation is investigated. The enhancement of the electrical conduction is interpreted in terms of electron trap filling of the native oxide via ammonia adsorption. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4768692]