Excitons in strain-induced one-dimensional moire potentials at transition metal dichalcogenide heterojunctions
Excitons in strain-induced one-dimensional moire potentials at transition metal dichalcogenide heterojunctions
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DOI：
10.1038/s41563-020-0730-8
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发表时间：
2020-07-13
期刊：
影响因子：
41.2
通讯作者：
Zhu, X-Y
中科院分区：
文献类型：
--
作者：
Bai, Yusong;Zhou, Lin;Zhu, X-Y
最近，将层间激子限制在界面莫尔图案中的可能性作为在过渡金属二硫族化物异质结构中形成零维量子发射器和拓扑超晶格的有序阵列的策略而受到关注。应变预计将在莫尔势景观的调制中发挥重要作用，将量子点状零维陷阱阵列调整为一维量子线的平行条纹。在这里，我们提出了无应变零维和应变诱导一维莫尔图案的实空间成像，以及 WSe2/MoSe(2) 异双层相应激子发射的光致发光测量。零维莫尔陷阱中的激子显示出类似量子发射器的圆偏振尖锐光致发光峰，而一维莫尔势中的激子的光致发光发射则显示出线性偏振和两个数量级的高强度。这些结果表明应变工程是一种根据需要定制莫尔势及其光电响应的有效方法。压响应力显微镜和光学测量的结合揭示了应变在一维莫尔图案形成中的影响以及范德华异质结构中层间激子的行为。
The possibility of confining interlayer excitons in interfacial moire patterns has recently gained attention as a strategy to form ordered arrays of zero-dimensional quantum emitters and topological superlattices in transition metal dichalcogenide heterostructures. Strain is expected to play an important role in the modulation of the moire potential landscape, tuning the array of quantum dot-like zero-dimensional traps into parallel stripes of one-dimensional quantum wires. Here, we present real-space imaging of unstrained zero-dimensional and strain-induced one-dimensional moire patterns along with photoluminescence measurements of the corresponding excitonic emission from WSe2/MoSe(2)heterobilayers. Whereas excitons in zero-dimensional moire traps display quantum emitter-like sharp photoluminescence peaks with circular polarization, the photoluminescence emission from excitons in one-dimensional moire potentials shows linear polarization and two orders of magnitude higher intensity. These results establish strain engineering as an effective method to tailor moire potentials and their optoelectronic response on demand.The combination of piezoresponse force microscopy and optical measurements reveals the influence of strain in the formation of one-dimensional moire patterns and the resulting behaviour of interlayer excitons in van der Waals heterostructures.