Transport and electronic properties of a polar semiconductor junction

Besides molecular junctions, polar semiconductor junctions may also be suitable candidates for nm-scale electronic active devices. Here, the current density-voltage (J-V) characteristics and partial densities of states (PDOS) have been calculated for an Au/AlN/Au junction with a two-bilayer thick AlN[0001] layer. Results show that when $V_{bias}$, which is defined as the electric potential at the Al-side electrode relative to that at the N-side electrode, is positive, the J-V curve is approximately ohmic up to $V_{bias}\approx 0.4V$. Then J drops suddenly to a small value. Beyond $V_{bias}\approx 0.4V$, J exhibits approximately three steps at J$\approx$3, 20, 39 nA/$a_{0}^{2}$ in $0.4V