Demonstration of Forward Inter-band Tunneling in GaN by Polarization Engineering

TL;DR

This paper demonstrates high-performance forward interband tunneling in GaN heterojunctions through polarization engineering, achieving high current densities and negative differential resistance at room temperature, relevant for solar cell applications.

Contribution

It introduces a novel polarization-engineered GaN/InGaN/GaN tunnel diode with record high forward tunneling currents and observable negative differential resistance at room temperature.

Findings

Achieved 153 mA/cm2 at 10 mV in GaN tunnel junctions.

Observed negative differential resistance with PVCR of 4.

Demonstrated current densities suitable for multi-junction solar cells.

Abstract

We report on the design, fabrication, and characterization of GaN interband tunnel junction showing forward tunneling characteristics. We have achieved very high forward tunneling currents (153 mA/cm2 at 10 mV, and 17.7 A/cm2 peak current) in polarization-engineered GaN/InGaN/GaN heterojunction diodes grown by plasma assisted molecular beam epitaxy. We also report the observation of repeatable negative differential resistance in interband III-Nitride tunnel junctions, with peak-valley current ratio (PVCR) of 4 at room temperature. The forward current density achieved in this work meets the typical current drive requirements of a multi-junction solar cell.