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.
@article{arxiv.1606.00509,
title = {High Current Density 2D/3D Esaki Tunnel Diodes},
author = {Sriram Krishnamoorthy and Edwin W. Lee and Choong Hee Lee and Yuewei Zhang and William D. McCulloch and Jared M. Johnson and Jinwoo Hwang and Yiying Wu and Siddharth Rajan},
journal= {arXiv preprint arXiv:1606.00509},
year = {2016}
}