Controlling the electronic properties of silicon nanowires with functional molecular groups

Attachment of a simple polar molecule, terpyridine, to the surfaces of Si nanowires with diameters ranging from 7-100 nm was investigated with two terminal conductivity measurements, a unique single nanowire photoelectron spectroscopy, and theoretical analysis. Our experiments reveal the details of molecule-nanowire bonding and charge transfer, diameter dependent Fermi level shifts, and acid attachment leading to conductivity in the cylindrical molecular nanolayer surrounding the nanowire.