Low Resistance GaN/InGaN/GaN Tunnel Junctions

TL;DR

This paper demonstrates low-resistance GaN/InGaN/GaN tunnel junctions enabling efficient hole injection, which can improve III-nitride optoelectronic devices by replacing resistive p-contacts with tunneling layers.

Contribution

It introduces a novel low-resistance tunnel junction design with a specific resistivity of 1.2×10^-4 Ω·cm², advancing carrier injection in III-nitride devices.

Findings

Achieved low-resistance tunnel junctions with specific resistivity of 1.2×10^-4 Ω·cm²

Reduced tunneling barrier using band gap engineering and polarization fields

Potential to replace resistive p-contacts, enhancing light extraction

Abstract

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.