<br>使用双电层门控悬浮 MoTe2 中应变诱导的 2H 到 1T′ 相变,ACS Nano

当前位置： X-MOL 学术 › ACS Nano › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

使用双电层门控悬浮 MoTe2 中应变诱导的 2H 到 1T′ 相变
ACS Nano ( IF 15.8 ) Pub Date : 2023-11-10 , DOI: 10.1021/acsnano.3c04701
Shubham Sukumar Awate ₁ , Ke Xu _{1,

2,

3} , Jierui Liang ₁ , Benjamin Katz ₄ , Ryan Muzzio ₅ , Vincent H Crespi _{4,

6,

7} , Jyoti Katoch ₅ , Susan K Fullerton-Shirey _{1,

8}

Affiliation

通过热、电化学掺杂和应变等多种刺激，MoTe ₂可以从半导体（2H）相转变为半金属（1T'）相。这种类型的相变如果是可逆的并且是门控的，则可用于低功耗存储器和逻辑。在这项工作中，通过少层悬浮 MoTe ₂场效应晶体管中的应变演示了栅极控制且完全可逆的 2H 到 1T' 相变。使用单离子导电固体聚合物电解质通过悬浮通道的双电层门控来施加应变。通过同时电传输和拉曼光谱证实了相变。当V _SG ≥ 2.5 V 时，观察到面外振动峰值 (A _1g )（1T' 相的特征）。此外，还检测到面内振动模式 (E _2g ) 的红移，即应变引起的声子位移的特征。根据位移的大小，根据密度泛函理论估计应变为 0.2-0.3%。从电气角度来看，当V _SG ≥ 2 V 时，电阻温度系数从负转变为正，证实了从半导体到金属的转变。这里提出的门控可逆应变方法可以扩展到其他二维材料的应变，探索基本材料特性，并引入电子器件功能。

"点击查看英文标题和摘要"

Strain-Induced 2H to 1T′ Phase Transition in Suspended MoTe2 Using Electric Double Layer Gating

MoTe₂ can be converted from the semiconducting (2H) phase to the semimetallic (1T′) phase by several stimuli including heat, electrochemical doping, and strain. This type of phase transition, if reversible and gate-controlled, could be useful for low-power memory and logic. In this work, a gate-controlled and fully reversible 2H to 1T′ phase transition is demonstrated via strain in few-layer suspended MoTe₂ field effect transistors. Strain is applied by the electric double layer gating of a suspended channel using a single ion conducting solid polymer electrolyte. The phase transition is confirmed by simultaneous electrical transport and Raman spectroscopy. The out-of-plane vibration peak (A_1g)─a signature of the 1T′ phase─is observed when V_SG ≥ 2.5 V. Further, a redshift in the in-plane vibration mode (E_2g) is detected, which is a characteristic of a strain-induced phonon shift. Based on the magnitude of the shift, strain is estimated to be 0.2–0.3% by density functional theory. Electrically, the temperature coefficient of resistance transitions from negative to positive at V_SG ≥ 2 V, confirming the transition from semiconducting to metallic. The approach to gate-controlled, reversible straining presented here can be extended to strain other two-dimensional materials, explore fundamental material properties, and introduce electronic device functionalities.

更新日期：2023-11-10

点击分享查看原文

点击收藏

公开下载

阅读更多本刊新发论文本刊介绍/投稿指南