Garrity Oisín, Brumme Thomas, Bergmann Annika, Korn Tobias, Kusch Patryk, Reich Stephanie
Department of Physics, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany.
Chair of Theoretical Chemistry, Technische Universität Dresden, Bergstraße 66, 01069 Dresden, Germany.
Nano Lett. 2024 Sep 25;24(38):11853-11858. doi: 10.1021/acs.nanolett.4c02757. Epub 2024 Sep 12.
Transition metal dichalcogenide heterostructures have garnered strong interest for their robust excitonic properties, mixed light-matter states such as exciton-polaritons, and tailored properties, vital for advanced device engineering. Two-dimensional heterostructures inherit their physics from monolayers with the addition of interlayer processes that have been particularly emphasized for their electronic and optical properties. Here, we demonstrate the interlayer coupling of the MoSe phonons to WSe excitons in a WSe/MoSe heterostructure using resonant Raman scattering. The WSe monolayer induces an interlayer resonance in the Raman cross-section of the MoSe A phonons. Frozen-phonon calculations within density functional theory reveal a strong deformation-potential coupling between the A MoSe phonon and the electronic states of the close-by WSe layer approaching 20% of the intralayer coupling to the MoSe electrons. Understanding the vibrational properties of van der Waals heterostructures requires going beyond the sum of their constituents and considering cross-material coupling.
过渡金属二硫属化物异质结构因其稳健的激子特性、混合的光与物质状态（如激子极化激元）以及定制特性而备受关注，这些特性对于先进器件工程至关重要。二维异质结构继承了单层的物理特性，并增加了层间过程，这些过程因其电子和光学特性而备受关注。在此，我们利用共振拉曼散射证明了在WSe/MoSe异质结构中MoSe声子与WSe激子的层间耦合。WSe单层在MoSe A声子的拉曼截面中诱导出层间共振。密度泛函理论中的冻结声子计算揭示了A MoSe声子与附近WSe层的电子态之间存在强烈的形变势耦合，接近层内与MoSe电子耦合的20%。理解范德华异质结构的振动特性需要超越其组成部分的总和，并考虑跨材料耦合。
