Investigations on the sensing mechanisms in silicon nanowire Schottky-barrier field effect sensors

摘要

Surface functionalization of NiSi_2-Si-NiSi_2 nanowire heterostructures, acting as Schottky-junction field effect transistors (SB-FETs) represent a promising route for biosensor applications. Axially Ni-silicidized silicon nanowires exhibit a very sharp metalsemiconductor interface, thus forming a well defined and reproducible Schottky barrier. These barriers determine the current through the wire and can be changed by small molecules chemiadsorbed on the nanowire surface. We report that surface modifications can alter the polarity of the devices. This severe influence on the charge transport implies ultrahigh sensitivity for nanowire SB-FETs.