Steeger Paul, Graalmann Jan-Hauke, Schmidt Robert, Kupenko Ilya, Sanchez-Valle Carmen, Marauhn Philipp, Deilmann Thorsten, de Vasconcellos Steffen Michaelis, Rohlfing Michael, Bratschitsch Rudolf
Institute of Physics and Center for Nanotechnology, University of Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany.
Institute of Solid State Theory, University of Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany.
Nano Lett. 2023 Oct 11;23(19):8947-8952. doi: 10.1021/acs.nanolett.3c02428. Epub 2023 Sep 21.
The optical and electronic properties of multilayer transition metal dichalcogenides differ significantly from their monolayer counterparts due to interlayer interactions. The separation of individual layers can be tuned in a controlled way by applying pressure. Here, we use a diamond anvil cell to compress bilayers of 2H-MoS in the gigapascal range. By measuring optical transmission spectra, we find that increasing pressure leads to a decrease in the energy splitting between the A and the interlayer exciton. Comparing our experimental findings with calculations, we conclude that the observed changes are not due to the commonly assumed hydrostatic compression. This effect is attributed to the MoS bilayer adhering to the diamond, which reduces the in-plane compression. Moreover, we demonstrate that the distinct real-space distributions and resulting contributions from the valence band account for the different pressure dependencies of the inter- and intralayer excitons in compressed MoS bilayers.
由于层间相互作用，多层过渡金属二硫化物的光学和电子性质与其单层对应物有显著差异。通过施加压力，可以以可控的方式调节各层之间的间距。在此，我们使用金刚石对顶砧在吉帕斯卡范围内压缩2H-MoS双层膜。通过测量光透射光谱，我们发现压力增加会导致A激子和层间激子之间的能量分裂减小。将我们的实验结果与计算结果进行比较，我们得出结论，观察到的变化并非由于通常假设的流体静压力压缩。这种效应归因于MoS双层膜附着在金刚石上，这降低了面内压缩。此外，我们证明了价带不同的实空间分布及其产生的贡献解释了压缩MoS双层膜中层间激子和层内激子不同的压力依赖性。
