# Influence of interface dielectric disorder on interlayer excitons in mixed binary/ternary TMD heterostructures

## TL;DR

This paper investigates how interface disorder affects the properties of interlayer excitons in transition metal dichalcogenide heterostructures.

## Contribution

The study identifies dielectric disorder at the interface as a key factor in broadening the linewidths of interlayer excitons.

## Key findings

- Interlayer excitons in binary–ternary heterostructures have significantly broader linewidths than intralayer excitons.
- Dielectric disorder from interface inhomogeneities is attributed to the observed line broadening.
- Photoluminescence measurements reveal multiple excitonic transitions in the heterostructures.

## Abstract

In this paper, we study the excitonic linewidths and peak energies in two transition metal dichalcogenide heterostructures of Mo0.5W0.5Se2 and its binary counterparts, MoSe2 and WSe2. We observe spectra composed of several individual excitonic transitions in temperature-dependent photoluminescence measurements. Among these are transitions of neutral excitons and trions from the binary layers and the interlayer excitons from the heterostructures. The luminescence linewidth of the interlayer excitons is significantly broader than the linewidths of the excitonic transitions from the binary layers. We attribute this additional line broadening to dielectric disorder caused by spatial inhomogeneity at the interface.

Interlayer excitons in binary–ternary heterostructures show much broader linewidths than those in intralayer binary monolayers. A phenomenon is attributed to dielectric disorder caused by interface inhomogeneities and alloy disorder.