Ambipolar conduction in transistors using solution grown InAs nanowires with Cd doping

Nanowire field effect transistors have been fabricated using Cd doped InAs nanowires synthesized using a solution-liquid-solid technique. Both n-channel and p-channel characteristics have been observed, which implies that the surface Fermi level is not pinned in the conduction band. The observation of a p channel is attributed to the passivation of surface states by surface ligands introduced during nanowire synthesis and to the effects of heavy acceptor doping. Devices in which the surface ligands are removed by O-2 plasma treatment exhibit only n-channel conduction, which would be consistent with surface Fermi level pinning in the conduction band. (c) 2007 American Institute of Physics.