Layer-Transferred MoS2/GaN PN Diodes

TL;DR

This paper reports on the fabrication and characterization of MoS2/GaN heterojunction diodes, demonstrating high-quality transfer, rectification, and band offset measurement, highlighting their potential for novel electronic and optoelectronic devices.

Contribution

It introduces a method for transferring CVD-grown MoS2 onto GaN substrates and characterizes the resulting heterojunction diodes, providing insights into their electronic properties.

Findings

High-quality MoS2 transferred onto GaN substrates.

Excellent diode rectification observed.

Conduction band offset of ~0.2 eV measured.

Abstract

Electrical and optical characterization of two-dimensional/three-dimensional (2D/3D) p-molybdenum disulfide/n-gallium nitride (p-MoS2/n-GaN) heterojunction diodes are reported. Devices were fabricated on high-quality, large-area p-MoS2 grown by chemical vapor deposition (CVD) on hexagonal sapphire substrates. The processed devices were transferred onto GaN/sapphire substrates, and the transferred films were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM). On-axis XRD spectra and surface topology obtained from AFM scans were consistent with previously grown high-quality, continuous MoS2 films. Current-voltage measurements of these diodes exhibited excellent rectification, and capacitance-voltage measurements were used to extract a conduction band offset of approximately 0.2 eV for the transferred MoS2/GaN heterojunction. This conduction band offset was confirmed by internal photoemission (IPE) measurements. The energy band lineup of the MoS2/GaN heterojunction is proposed here. This work demonstrates the potential of 2D/3D heterojunctions for novel device applications.