Photoluminescence imaging of single photon emitters within nanoscale strain profiles in monolayer WSe${}_2$

Abstract

Local deformation of atomically thin van der Waals materials provides a powerful approach to create site-controlled chip-compatible single-photon emitters (SPEs). However, the microscopic mechanisms underlying the formation of such strain-induced SPEs are still not fully clear, which hinders further efforts in their deterministic integration with nanophotonic structures for developing practical on-chip sources of quantum light. Here we investigate SPEs with single-photon purity up to 98% created in monolayer WSe${}_2$ via nanoindentation. Using photoluminescence imaging in combination with atomic force microscopy, we locate single-photon emitting sites on a deep sub-wavelength spatial scale and reconstruct the details of the surrounding local strain potential. The obtained results suggest that the origin of the observed single-photon emission is likely related to strain-induced spectral shift of dark excitonic states and their hybridization with localized states of individual defects.

8 pages, 4 figures

References in corpus (5)

• Bright single photon emitters with enhanced quantum efficiency in a two-dimensional semiconductor coupled with dielectric nano-antennas
• Purcell-enhanced single photon source based on a deterministically placed WSe${}_2$ monolayer quantum dot in a circular Bragg grating cavity
• Multipath optical recombination of intervalley dark excitons and trions in monolayer WSe${}_2$
• Strain control of hybridization between dark and localized excitons in a 2D semiconductor
• Exciton fine structure splitting and linearly polarized emission in strained transition-metal dichalcogenide monolayers

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• Deterministic and Scalable Quantum Light Generation in DNA Origami-Programmed Organic Molecule-MoS${}_2$ Monolayer Hybrids