Electron transport in carbon nanotube-silicon heterodimensional heterojunction array: An experimental investigation

Current-voltage experiments on a highly ordered array of carbon nanotubes interfaced with silicon reveal interesting features arising from the regular array of heterojunctions between one-dimensional (1D) and three-dimensional materials. At high temperature, the vertically aligned and ordered nanotubes behave as an array of point junction contacts to the silicon below, which merge into a planar junction as temperature decreases. This model is further supported by the observation of signature space charge limited conduction, whose origin is attributed to deep levels in the silicon substrate and to the strong field enhancement due to the quasi-1D nanotubes.