Thermal light emission from monolayer MoS2

TL;DR

This paper reports on thermal light emission from monolayer MoS2, exploring its potential for optoelectronic applications and providing insights into electron-phonon interactions under high bias conditions.

Contribution

It demonstrates thermal light emission in monolayer MoS2, a novel observation that advances understanding of light emission mechanisms in 2D materials.

Findings

Thermal emission observed in monolayer MoS2 under high bias.

Provides insights into electron-phonon interactions in 2D materials.

Highlights potential for optoelectronic device applications.

Abstract

Because of their strong excitonic photoluminescence (PL) and electroluminescence (EL), together with an excellent electronic tunability, transition metal dichalcogenide (TMD) semiconductors are promising candidates for novel optoelectronic devices. In recent years, several concepts for light emission from two-dimensional (2D) materials have been demonstrated. Most of these concepts are based on the recombination of electrons and holes in a pn-junction, either along the lateral direction using split-gate geometries in combination with monolayer TMDs, or by precisely stacking different 2D semiconductors on top of each other, in order to fabricate vertical van der Waals heterostructures, working as light-emitting diodes (LEDs). Further, EL was also observed along the channel of ionic liquid gated field-effect transistors (FETs) under ambipolar carrier injection. Another mechanism, which has been studied extensively in carbon nanotubes (CNTs) and more recently also in graphene, is thermal light emission as a result of Joule heating. Although the resulting efficiencies are smaller than that of LEDs based on ambipolar electron-hole injection, these experiments provide valuable insights into microscopic processes, such as electron-phonon and phonon-phonon interactions, and the behavior of low-dimensional materials under strong bias in general.