GaN-Based Light Emitting Diodes with Tunnel Junctions

Abstract

We have demonstrated hole injection through a tunnel junction embedded in the GaN-based light emitting diode structure. The tunnel junction consists of 30 nm GaN:Si ++ and 15 nm InGaN:Mg ++ grown on a GaN–InGaN quantum well heterostructure. The forward voltage of the light emitting diode, including the voltage drop across the reverse-biased tunnel junction, is 4.1 V at 50 A/cm 2 , while that of a standard light emitting diode with a conventional contact structure is 3.5 V. The light output of the diode with the tunnel junction is comparable to that of the standard device. This tunnel junction eliminates the need for a highly resistive p-AlGaN cladding layer in short-wavelength laser diodes and the semi-transparent electrode required for current spreading in conventional GaN-based light emitting diodes.