High Current Density 2D/3D Esaki Tunnel Diodes

TL;DR

This paper demonstrates a high current density 2D/3D Esaki tunnel diode using MoS2 and GaN, achieving significant negative differential resistance and modeling the device to understand its electrostatics.

Contribution

It introduces a novel 2D/3D heterojunction Esaki diode with record current density and provides a model treating MoS2 as a bulk semiconductor to explain device behavior.

Findings

Peak current density of 446 A/cm2 at room temperature

Achieved 1 kA/cm2 in Zener mode at -1 V bias

Electrostatics at the 2D/3D interface are crucial for device performance

Abstract

The integration of two-dimensional materials such as transition metal dichalcogenides with bulk semiconductors offer interesting opportunities for 2D/3D heterojunction-based novel device structures without any constraints of lattice matching. By exploiting the favorable band alignment at the GaN/MoS2 heterojunction, an Esaki interband tunnel diode is demonstrated by transferring large area, Nb-doped, p-type MoS2 onto heavily n-doped GaN. A peak current density of 446 A/cm2 with repeatable room temperature negative differential resistance, peak to valley current ratio of 1.2, and minimal hysteresis was measured in the MoS2/GaN non-epitaxial tunnel diode. A high current density of 1 kA/cm2 was measured in the Zener mode (reverse bias) at -1 V bias. The GaN/MoS2 tunnel junction was also modeled by treating MoS2 as a bulk semiconductor, and the electrostatics at the 2D/3D interface was found to be crucial in explaining the experimentally observed device characteristics.