Deterministic Localization of Strain-Induced Single-Photon Emitters in Multilayer GaSe

The nanoscale strain has emerged as a powerful tool forcontrollingsingle-photon emitters (SPEs) in atomically thin transition metaldichalcogenides (TMDCs). However, quantum emitters in monolayer TMDCsare typically unstable in ambient conditions. Multilayer TMDCs couldbe a solution, but they suffer from low quantum efficiency, resultingin low brightness of the SPEs. Here, we report the deterministic spatiallocalization of strain-induced SPEs in multilayer GaSe by nanopillararrays. The strain-controlled quantum confinement effect introduceswell-isolated sub-bandgap photoluminescence and corresponding suppressionof the broad band edge photoluminescence. Clear photon-antibunchingbehavior is observed from the quantum dot-like GaSe sub-bandgap excitonemission at 3.5 K. The strain-dependent confinement potential andthe brightness are found to be strongly correlated, suggesting a promisingroute for tuning and controlling SPEs. The comprehensive investigationsof strain-engineered GaSe SPEs provide a solid foundation for thedevelopment of 2D devices for quantum photonic technologies.