  Due to their wide band gaps, III-N materials can exhibit behaviors ranging
from the semiconductor class to the dielectric class. Through an analogy
between a Metal/AlGaN/AlN/GaN diode and a MOS contact, we make use of this dual
nature and show a direct path to capture the energy band diagram of the nitride
system. We then apply transparency calculations to describe the forward
conduction regime of a III-N heterojunction diode and demonstrate it realizes a
tunnel diode, in contrast to its regular Schottky Barrier Diode designation.
Thermionic emission is ruled out and instead, a coherent electron tunneling
scenario allows to account for transport at room temperature and higher.
