Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, IL, 60208, USA.
Department of Physics and Astronomy, Northwestern University, Evanston, IL, 60208, USA.
Nat Commun. 2023 Apr 17;14(1):2193. doi: 10.1038/s41467-023-37892-0.
Two-dimensional (2D) materials have attracted attention for quantum information science due to their ability to host single-photon emitters (SPEs). Although the properties of atomically thin materials are highly sensitive to surface modification, chemical functionalization remains unexplored in the design and control of 2D material SPEs. Here, we report a chemomechanical approach to modify SPEs in monolayer WSe through the synergistic combination of localized mechanical strain and noncovalent surface functionalization with aryl diazonium chemistry. Following the deposition of an aryl oligomer adlayer, the spectrally complex defect-related emission of strained monolayer WSe is simplified into spectrally isolated SPEs with high single-photon purity. Density functional theory calculations reveal energetic alignment between WSe defect states and adsorbed aryl oligomer energy levels, thus providing insight into the observed chemomechanically modified quantum emission. By revealing conditions under which chemical functionalization tunes SPEs, this work broadens the parameter space for controlling quantum emission in 2D materials.
二维（2D）材料由于其能够容纳单光子发射器（SPE）而引起了量子信息科学的关注。尽管原子薄材料的性质对表面修饰非常敏感，但在 2D 材料 SPE 的设计和控制中，化学功能化仍未得到探索。在这里，我们报告了一种通过局部机械应变和非共价表面功能化与芳基重氮化学的协同组合来修饰单层 WSe 中 SPE 的化学机械方法。在沉积芳基寡聚物吸附层之后，应变单层 WSe 的光谱复杂的与缺陷相关的发射被简化为具有高单光子纯度的光谱孤立的 SPE。密度泛函理论计算揭示了 WSe 缺陷态和吸附的芳基寡聚物能级之间的能量对准，从而为观察到的化学机械修饰的量子发射提供了深入的了解。通过揭示化学功能化调节 SPE 的条件，这项工作拓宽了控制二维材料中量子发射的参数空间。
