  Enhanced interband tunnel injection of holes into a PN junction is
demonstrated using P-GaN/InGaN/N-GaN tunnel junctions with a specific
resistivity of 1.2 X 10-4 {\Omega} cm2. The design methodology and
low-temperature characteristic of these tunnel junctions is discussed, and
insertion into a PN junction device is described. Applications of tunnel
junctions in III-nitride optoelectronics devices are explained using energy
band diagrams. The lower band gap and polarization fields reduce tunneling
barrier, eliminating the need for ohmic contacts to p-type GaN. This
demonstration of efficient tunnel injection of carriers in III-Nitrides can
lead to a replacement of existing resistive p-type contact material in light
emitters with tunneling contact layers, requiring very little metal footprint
on the surface, resulting in enhanced light extraction from top emitting
emitters.
