Tunnel junctions in GaN/AlN for optoelectronic applications

The authors propose a new device design using the polarization properties of the III-nitrides system that eliminates the need for high doping concentrations and has the further benefit of potentially eliminating problematic p-type contacts. P-type material in the nitrides is plagued by high contact resistance and high sheet resistance. These problems could be eliminated by contacting n-type material that acts as a current spreading layer and using a tunnel junction to transfer current to p-type material with minimal losses (Takeuchi et al., 2001)