Phase Transition of MoTe 2 Controlled in van der Waals Heterostructure Nanoelectromechanical Systems
Phase Transition of MoTe 2 Controlled in van der Waals Heterostructure Nanoelectromechanical Systems
复制标题
范德华异质结构纳米机电系统中 MoTe 2 相变的控制
DOI：
10.1002/smll.202205327
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发表时间：
2022
期刊：
影响因子：
13.3
通讯作者：
Feng, Philip X. ‐L.
中科院分区：
文献类型：
--
作者：
Ye, Fan;Islam, Arnob;Wang, Yanan;Guo, Jing;Feng, Philip X. ‐L.
在货车纳机电系统（NEMS）平台上，采用六方氮化硼包裹的MoTe2结构，通过热力学和机械学机制控制MoTe2的可逆晶相转变。得益于悬浮的vdW异质结构中非常有效的加热和应变效应，MoTe 2相变由升高的温度和应变水平触发。拉曼光谱原位监测MoTe 2晶相特征，并清楚地记录了六方2H（半导体）和单斜1T′（金属）相之间的可逆相变。结合拉曼测温法，精确测量的vdW器件的纳米机械共振，使应变变化的确定和监测，因为温度是由温度控制调节。这些结果不仅加深了对MoTe2相变的理解，而且为MoTe2相变和多物理器件的工程化提供了一个新的平台.
This work reports experimental demonstrations of reversible crystalline phase transition in ultrathin molybdenum ditelluride (MoTe2) controlled by thermal and mechanical mechanisms on the van der Waals (vdW) nanoelectromechanical systems (NEMS) platform, with hexagonal boron nitride encapsulated MoTe2structure residing on top of graphene layer. Benefiting from very efficient electrothermal heating and straining effects in the suspended vdW heterostructures, MoTe2phase transition is triggered by rising temperature and strain level. Raman spectroscopy monitors the MoTe2crystalline phase signatures in situ and clearly records reversible phase transitions between hexagonal 2H (semiconducting) and monoclinic 1T′ (metallic) phases. Combined with Raman thermometry, precisely measured nanomechanical resonances of the vdW devices enable the determination and monitoring of the strain variations as temperature is being regulated by electrothermal control. These results not only deepen the understanding of MoTe2phase transition, but also demonstrate a novel platform for engineering MoTe2phase transition and multiphysical devices.