博士生李少菲同学在Optics Letters上发表论文

课题组博士生李少菲同学在Optics Letters上发表论文

    近日，课题组博士生李少菲同学在刘老师的指导下，以第一作者在Optics Letters上发表题为“Layer-dependent excitonic valley polarization properties in MoS₂–WS₂ heterostructures(MoS₂-WS₂异质结构中层数调控的激子谷偏振特性)”的实验论文。

      层状过渡金属二硫化物(TMDC)为原子薄材料和光电器件的基础研究铺平了道路。由于其固有的二维特性，少层 TMDCs 异质结构表现出几种对层数极为敏感的独特物理特性。然而，关于层间耦合对激子和谷极化的影响的研究仍然不足。本文中，我们使用圆偏振分辨光致发光研究了 MoS₂-WS₂ 异质结构中激子谷的偏振。在 1L-1L MoS₂-WS₂ 异质结构中，谷极化最大（~28.45%), 随着 WS₂ 层数的增加，A_WS2 的极化率降低。层相关的谷极化可以通过多层 WS₂ 的间接带隙性质来解释。我们进一步观察到随着 WS₂ 层数的增加，MoS₂-WS₂ 异质结构中激子 A_MoS2 发生红移，这归因于MoS₂ 能带边缘的位移，表明 MoS₂-WS₂异质结构的层敏感光学性质。我们的研究结果阐明了对多层MoS₂-WS₂异质结构中激子行为的理解，这可能促进它们在光电器件中的潜在应用。

 论文链接：https://opg.optica.org/ol/abstract.cfm?uri=ol-47-22-5861

Comments: 

• The study of layer-dependent excitonic valley polarization properties in MoS₂-WS₂ heterostructures is important because it has potential applications in the field of valleytronics. Valleytronics is a new type of electronics technology that utilizes the valley degree of freedom of electrons in certain materials.

• MoS₂ and WS₂ are two-dimensional (2D) materials that belong to the family of transition metal dichalcogenides (TMDs). They have unique electronic properties that are strongly dependent on the valley polarization of their electronic excitations. By combining MoS₂ and WS₂ in a heterostructure, researchers can take advantage of the different valley polarization properties of each material to achieve specific electronic functions.

• The layer-dependent excitonic valley polarization properties in MoS₂-WS₂ heterostructures are a result of the interactions between the electron-hole pairs and the surrounding environment. The valley polarization of the excitons can be tuned by changing the number of layers, the stacking order, and the orientation of the layers.

• In summary, the study of layer-dependent excitonic valley polarization properties in MoS₂-WS₂ heterostructures is important for developing new electronic devices and technologies based on valleytronics.