Deterministic Localization of Strain-induced Single-photon Emitters in Multilayer GaSe

TL;DR

This paper demonstrates a method for precisely locating strain-induced single-photon emitters in multilayer GaSe using nanopillar arrays, enhancing control for quantum photonic applications.

Contribution

It introduces a deterministic approach to localize SPEs in multilayer GaSe, overcoming stability and brightness issues in 2D TMDCs.

Findings

Strain induces well-isolated sub-bandgap photoluminescence.

Photon-antibunching confirms quantum emitter behavior at 3.5 K.

Brightness correlates with strain-controlled confinement potential.

Abstract

Nanoscale strain has emerged as a powerful tool for controlling single-photon emitters (SPEs) in atomically thin transition metal dichalcogenides (TMDCs)(1, 2). However, quantum emitters in monolayer TMDCs are typically unstable in ambient conditions. Multilayer two-dimensional (2D) TMDCs could be a solution, but they suffer from low quantum efficiency, resulting in low brightness of the SPEs. Here, we report the deterministic spatial localization of strain-induced single-photon emitters in multilayer GaSe by nanopillar arrays. The strain-controlled quantum confinement effect introduces well-isolated sub-bandgap photoluminescence and corresponding suppression of the broad band edge photoluminescence. Clear photon-antibunching behavior is observed from the quantum dot-like GaSe sub-bandgap exciton emission at 3.5 Kelvin. The strain-dependent confinement potential and the brightness are found to be strongly correlated, suggesting a promising route for tuning and controlling SPEs. The comprehensive investigations of strain-engineered GaSe SPEs provide a solid foundation for the development of 2D devices for quantum photonic technologies.