# Probing the Nanoscale Excitonic Landscape and Quantum Confinement of Excitons in Gated Monolayer Semiconductors

## TL;DR

This study uses cathodoluminescence spectroscopy to investigate nanoscale excitonic behavior and quantum confinement in gated monolayer WS2, revealing heterogeneity, confinement channels, and doping effects crucial for quantum photonics.

## Contribution

It introduces a high-resolution method to probe excitonic landscapes in 2D semiconductors under electrostatic gating, uncovering new confinement mechanisms and heterogeneity effects.

## Key findings

- Resolved a homojunction between gated and ungated regions.
- Discovered an exciton confinement channel due to unconventional doping.
- Provided insights into exciton manipulation via electron-beam and gate interactions.

## Abstract

Engineering and probing excitonic properties at the nanoscale remains a central challenge in quantum photonics and optoelectronics. While exciton confinement via electrical control and strain engineering has been demonstrated in 2D semiconductors, substantial nanoscale heterogeneity limits the scalability of 2D quantum photonic device architectures. In this work, we use cathodoluminescence spectroscopy to probe the excitonic landscape of monolayer $WS_2$ under electrostatic gating. Exploiting the high spatial resolution of the converged electron beam, we resolve a homojunction arising between gated and ungated regions. Moreover, we reveal an exciton confinement channel arising from an unconventional doping mechanism driven by the interplay between the electron beam and the applied gate fields. These findings offer new insights into the optoelectronic behavior of monolayer semiconductors under the combined influence of electron-beam excitation and electrostatic gating. Our approach provides a pathway for exciton manipulation at the nanoscale and opens opportunities for controlling quantum-confined exciton transport in two-dimensional materials.