Mechanism behind the switching of current induced by a gate field in a semiconducting nanowire junction

摘要

We propose a new orbital controlled model to explain the gate field inducedswitching of current in a semiconducting PbS-nanowire junction. A singleparticle scattering formalism in conjunction with a posteriori densityfunctional approach involving hybrid functional is used to study the electroniccurrent; both first and higher order Stark effects are explicitly treated inour model. Our calculation reveals that after a threshold gate-voltage, orbitalmixing produces p-components at the S atoms in the participating orbitals. Thisresults in an inter-layer orbital interaction that allows electron todelocalize along the channel axis. As a consequence a higher conductance stateis found. A similar feature is also found in a PbSe nanowire junction, whichsuggests that this model can be used universally to explain the gate fieldinduced switching of current in lead-chalcogenide nanowire junctions.