Electroluminescence in Single Layer MoS2

TL;DR

This paper reports the observation of electroluminescence in single-layer MoS2 transistors, highlighting its potential for optoelectronic applications due to its direct band gap and localized emission at contacts.

Contribution

It demonstrates electroluminescence in single-layer MoS2 and compares it with absorption and photoluminescence, revealing the same excited state involved.

Findings

Electroluminescence involves the same excited state as photoluminescence.

Electroluminescence shows threshold behavior and is localized at contacts.

Single-layer MoS2 is promising for 2D optoelectronic devices.

Abstract

We detect electroluminescence in single layer molybdenum disulphide (MoS2) field-effect transistors built on transparent glass substrates. By comparing absorption, photoluminescence, and electroluminescence of the same MoS2 layer, we find that they all involve the same excited state at 1.8eV. The electroluminescence has pronounced threshold behavior and is localized at the contacts. The results show that single layer MoS2, a direct band gap semiconductor, is promising for novel optoelectronic devices, such as 2-dimensional light detectors and emitters.