Wu Biao, Zheng Haihong, Li Shaofei, Wang Chang-Tian, Ding Junnan, He Jun, Liu Zongwen, Wang Jian-Tao, Liu Yanping
School of Physics and Electronics, Hunan Key Laboratory for Super-microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, Hunan 410083, People's Republic of China.
State Key Laboratory of High-Performance Complex Manufacturing, Central South University, 932 South Lushan Road, Changsha, Hunan 410083, People's Republic of China.
ACS Appl Mater Interfaces. 2023 Oct 18;15(41):48475-48484. doi: 10.1021/acsami.3c06949. Epub 2023 Oct 5.
Moiré superlattices have emerged as a promising platform for investigating and designing optically generated excitonic properties. The electronic band structure of these systems can be qualitatively modulated by interactions between the top and bottom layers, leading to the emergence of new quantum phenomena. However, the inhomogeneities present in atomically thin bilayer moiré superlattices created by artificial stacking have hindered a deeper understanding of strongly correlated electron properties. In this work, we report the fabrication of homogeneous moiré superlattices with controllable twist angles using a 2L-WSe/2L-WSe homostructure. By adding extra layers, we provide additional degrees of freedom to tune the optical properties of the moiré superlattices while mitigating the nonuniformity problem. The presence of an additional bottom layer acts as a buffer, reducing the inhomogeneity of the moiré superlattice, while the encapsulation effect of the additional top and bottom WSe monolayers further enhances the localized moiré excitons. Our observations of alternating circularly polarized photoluminescence confirm the existence of moiré excitons, and their characteristics were further confirmed by theoretical calculations. These findings provide a fundamental basis for studying moiré potential correlated quantum phenomena and pave the way for their application in quantum optical devices.
莫尔超晶格已成为研究和设计光生激子特性的一个有前景的平台。这些系统的电子能带结构可以通过顶层和底层之间的相互作用进行定性调制，从而导致新量子现象的出现。然而，通过人工堆叠创建的原子级薄双层莫尔超晶格中存在的不均匀性阻碍了对强关联电子特性的更深入理解。在这项工作中，我们报告了使用2L-WSe/2L-WSe同质结构制造具有可控扭转角的均匀莫尔超晶格。通过添加额外的层，我们提供了额外的自由度来调整莫尔超晶格的光学特性，同时减轻不均匀性问题。额外底层的存在起到了缓冲作用，减少了莫尔超晶格的不均匀性，而额外的顶部和底部WSe单层的封装效应进一步增强了局域化的莫尔激子。我们对交替圆偏振光致发光的观察证实了莫尔激子的存在，并且它们的特性通过理论计算得到了进一步证实。这些发现为研究莫尔势相关量子现象提供了基础，并为它们在量子光学器件中的应用铺平了道路。
