Low Resistivity GaN-Based Polarization-Induced Tunnel Junctions

The use of polarization charges in nitride based tunnel junctions enables a wide range of design approaches to increase the tunneling current to magnitudes usable in high efficiency GaN-based devices, including enhanced multijunction solar cells, optoelectronic and electronic devices. Here, an integrated computational model is used to explore and design the dopant concentration profile and implement the hybrid use of both AlGaN and InGaN layers to systematically optimize the configuration of polarization charges in the structure. The proposed tunnel junction structure, with indium composition and doping density compatible for insertion into a typical Ga-polar InGaN multiple-quantum well light-emitting diode structure, allows a high tunneling efficiency under reverse bias condition, achieving a resistivity of 7.8 × 10^-3 Ω·cm².