High Temperature Single Photon Emission Enabled by the Chemical Functionalization of Graphite-WSe₂Heterostructures

In addition to broad applications in optoelectronics, two-dimensional transition metal dichalcogenides can be engineered as sources of quantum light. Single photon emission (SPE) in monolayer tungsten diselenide (WSe₂₎ is prolific, observed from a myriad of defect and strain engineering techniques that yield high purity, deterministically placed emitters. However, a major challenge in the practical application of all these techniques is the low temperature required to observe defect-bound emission in WSe₂, which typically limits quality SPE to below 15K. Here, we demonstrate the ability to create high purity (>95%) SPE in nano-indented WSe₂ up to 80K using a synergistic approach combining recent advances of both heterostructure engineering and chemical functionalization [1,2]. Functionalization of a layered WSe₂/graphite heterostructure with nitrobenzene diazonium tetrafluoroborate (4-NBD) sustains spectrally isolated, high purity SPE up to 80K and measurable quantum emission up to 100K, demonstrating the versatility of chemical functionalization for improving quality of quantum emission in diverse van der Waals material surfaces.



[1] Utama, M. Iqbal Bakti, et al. Nature communications 14.1 (2023): 2193.

[2] Chuang, Hsun-Jen, et al. Nano Letters 24.18 (2024): <a href="tel:5529-5535">5529-5535.