Formation and characterization of silicon/carbon nanotube/silicon heterojunctions by local synthesis and assembly

This work investigates the formation of silicon/multiwalled carbon nanotube/silicon heterojunctions by in situ synthesizing carbon nanotubes between two heavily doped, suspended silicon microstructures that are separated 5–10μm apart using the techniques of localized heating and electric-field-assisted self-assembly. The local electric field has the strength of 0.2–1V∕μm. Tip- and root-grown carbon nanotubes are observed to form two different heterojunction morphologies at the tips as the former stop to grow and the latter continue to grow as the growth tips of carbon nanotubes reach the cold silicon. Experimental measurements of the silicon/carbon nanotube/silicon system show linear current-voltage characteristics indicating Ohmic contact behavior.