Scheitz Sarah, Glier Tomke Eva, Nweze Christian, van Heek Malte, Moch Isa, Zierold Robert, Blick Robert, Huse Nils, Rübhausen Michael
Institut für Nanostruktur- und Festkörperphysik, Center for Free Electron Laser Science (CFEL), Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany.
Institut für Nanostruktur- und Festkörperphysik, Center for Hybrid Nanostructures (CHyN), Universität Hamburg, Luruper Chaussee 149, Hamburg 22761, Germany.
ACS Appl Mater Interfaces. 2022 Jul 20;14(28):32625-32633. doi: 10.1021/acsami.2c04380. Epub 2022 Jul 11.
The electron-phonon interaction at the interface between topological insulator (TI), namely, BiSe and BiTe two-dimensional (2D) nanoflakes, to a gold substrate as a function of TI flake thickness is studied by means of Raman scattering. We reveal the presence of interface-enhanced Raman scattering and a strong phonon renormalization induced by carriers injected from the gold substrate to the topological surface in contact. We derive the change of the electron-phonon coupling showing a nearly linear behavior as a function of layer thickness. The strongly nonlinear change of the Raman scattering cross section as a function of flake thickness can be associated with band bending effects at the metal-TI interface. Our results provide spectroscopic evidence for a strongly modified band structure in the first few quintuple layers of BiSe and BiTe in contact with gold.
通过拉曼散射研究了拓扑绝缘体（TI），即BiSe和BiTe二维（2D）纳米片与金衬底之间界面处的电子 - 声子相互作用随TI薄片厚度的变化。我们揭示了界面增强拉曼散射的存在以及由从金衬底注入到接触的拓扑表面的载流子引起的强声子重整化。我们推导出电子 - 声子耦合的变化，其显示出作为层厚度函数的近乎线性行为。拉曼散射截面作为薄片厚度函数的强烈非线性变化可能与金属 - TI界面处的能带弯曲效应有关。我们的结果为与金接触的BiSe和BiTe的前几个五元层中强烈改变的能带结构提供了光谱证据。
