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arXiv 2012.15348physics.opticscond-mat.other
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MoSe2-WSe2异质结中层间激子的温度相关云纹俘获

Temperature dependent moiré trapping of interlayer excitons in MoSe2-WSe2 heterostructures

Fateme Mahdikhanysarvejahany, Daniel N. Meade, Christine Muccianti, Bekele H. Badada, Ithwun Idi, Adam Alfrey, Sean Raglow, Michael R. Koehler, David G. Mandrus… 展开作者

Fateme Mahdikhanysarvejahany, Daniel N. Meade, Christine Muccianti, Bekele H. Badada, Ithwun Idi, Adam Alfrey, Sean Raglow, Michael R. Koehler, David G. Mandrus, Takashi Taniguchi, Kenji Watanabe, Oliver L. A. Monti, Hongyi Yu, Brian J. LeRoy, John R. Schaibley

摘要:

MoSe 2-WSe 2异质结构具有强束缚的层间激子(IX),当扭转角接近0°或60°时,其表现出明亮的光致发光(PL)。在过去的几年里,已经有许多关于这些异质结构的光学响应的报道,但没有统一的模型来理解IX的动力学及其温度依赖性。在这里,我们进行了一个全面的研究的温度,激发功率,和随时间变化的PL的IX。我们观察到一个显着的降低PL强度以上的转变温度,我们归因于从本地化到离域IX的过渡。令人惊讶的是,我们发现IX PL能量和转变温度之间存在简单的反比关系,在0°和60°附近的样品中表现出相反的功率依赖行为。我们的结论是,这种温度依赖性是IX-IX交换相互作用的结果,其效果被抑制的摩尔势捕获IX在低温下。

英文摘要:

MoSe2-WSe2 heterostructures host strongly bound interlayer excitons (IXs) which exhibit bright photoluminescence (PL) when the twist-angle is near 0° or 60°. Over the past several years, there have been numerous reports on the optical response of these heterostructures but no unifying model to understand the dynamics of IXs and their temperature dependence. Here, we perform a comprehensive study of the temperature, excitation power, and time-dependent PL of IXs. We observe a significant decrease in PL intensity above a transition temperature that we attribute to a transition from localized to delocalized IXs. Astoundingly, we find a simple inverse relationship between the IX PL energy and the transition temperature, which exhibits opposite power dependent behaviors for near 0° and 60° samples. We conclude that this temperature dependence is a result of IX-IX exchange interactions, whose effect is suppressed by the moiré potential trapping IXs at low temperature.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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