Electronic Structure of Cdse Nanowires Terminated With Gold Electrodes

Abstract

Cadmium selenide nanowires in the wurtzite bulk phase, connected to gold electrodes are studied using local density approximation. The short wire is fully metalized by metal-induced gap states. For longer wires, a gap similar to that in bare cadmium selenide nanowires is observed near the center while sub-gap structure emerges near the metal-semiconductor nanocontact. This behavior is attributed to the formation of sub-gap interface states that vanish rapidly towards the center of the wire, consistent with experimental results. For the longer wires Schottky barriers develop with heights larger than the corresponding bulk value. Our study thus indicates that the length of the naonowire sandwitched between gold electrodes should be greater than 8.76 Å to get characteristics of bare CdSe nanowire.