课题组博士后郑海红在Optics Letters上发表论文

课题组博士后郑海红同学在Optics Letters上发表论文

    近日，课题组博士后郑海红同学在刘老师的指导下，以第一作者在Optics Letters上发表题为“Strain-Tunable Valley Polarization and Localized Excitons in Monolayer WSe₂(单层WSe₂中应变可调的谷极化和局域激子特性)”的实验论文。

      单层过渡金属二硫化物(TMDs)具有破缺空间反演对称性的晶体结构，因此成为了具有希望的谷电子学应用的候选材料。然而，由于存在谷间散射，谷极化程度通常不高。本文利用纳米压痕技术在Au阵列上制备了WSe₂单层的应变结构，从而展示了单层WSe₂中应变局域激子的产生和检测。使用低温光致发光(PL)光谱测量，观察到应变局域激子的增强发射，表现为两个锐利的PL峰。我们将这些新出现的锐利峰归因于被局部应变形成的势阱中的激子。此外，单层WSe₂的谷极化可以通过等离子体和磁场调制，而应变局域激子的谷极化增加，高达约79.6%。我们的结果表明，在WSe₂单层中可以实现应变可调的谷极化和局域激子，这可能对谷电子学应用有用。

 论文链接：https://opg.optica.org/ol/abstract.cfm?uri=ol-48-9-2393

Comments: 

This article discusses the potential use of strained structures of monolayer WSe₂ for valleytronic applications. The authors demonstrate the generation and detection of strained localized excitons in WSe₂ monolayers using nanoindentation techniques, and observe enhanced emission of these excitons as two sharp photoluminescence peaks in low-temperature PL spectroscopy. They attribute the emergence of these sharp peaks to excitons trapped in potential wells formed by local strains.

The authors further investigate the modulation of valley polarization in WSe₂ monolayers by plasmons and magnetic fields, and show that the valley polarization of strained localized excitons is increased, reaching a high value of approximately 79.6%. These results suggest that strain-tunable valley polarization and localized excitons can be realized in WSe₂ monolayers, which may have important implications for the development of valleytronic devices.

Overall, this article presents an interesting and potentially important development in the field of valleytronics, and the use of nanoindentation techniques to generate strained structures in monolayer materials could have wider implications for the study of 2D materials in general.