Ab initio calculations of quantum transport of Au–GaN–Au nanoscale junctions

Abstract

We investigate the contact geometry and electronic transport properties of a GaN pair sandwiched between Au electrodes by performing density functional theory plus the non-equilibrium Green's function method. The Au–GaN–Au junction breaking process is simulated. We calculate the corresponding cohesion energy and obtain the equilibrium conductance and the projected density of states of junctions. We also calculate the pulling force of the four configurations, and the spatial electron density difference after the junction is broken. In addition, the current of junctions is computed under small bias. It is found that all junctions have large conductance showing a non-linear I–V relationship.