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Electric-field Control of Electronic States in WS2 Nanodevices by Electrolyte Gating
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Nonvolatile Electrical Valley Manipulation in WS2 by Ferroelectric Gating
Xu Li1, Chengbiao Yang1, Yuanzheng Xia1
1Department of Physics, Engineering Research Center for Micro-Nano Optoelectronic Materials and Devices, Ministry of Education, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Jiujiang Research Institute, Xiamen University, Xiamen361005, P.R. China.
ACS Nano
|November 22, 2022
Summary
Ferroelectric gating nonvolatily tunes valley excitons in tungsten disulfide (WS2) by enhancing electron-phonon interactions. This breakthrough boosts room-temperature valley polarization for advanced valleytronics devices.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanotechnology
Background:
- Valleytronics utilizes electron valley properties for information processing.
- Transition metal dichalcogenides like WS2 are promising for valleytronics.
- Electrical control of valley properties is crucial for device applications.
Purpose of the Study:
- To achieve nonvolatile electrical tuning of valley-excitonic properties in WS2 using ferroelectric gating.
- To differentiate the effects of carrier doping versus ferroelectric coupling on valley polarization.
- To investigate the potential for room-temperature valleytronics applications.
Main Methods:
- Fabrication of monolayer and bilayer WS2 devices.
- Application of ferroelectric gating with varying electrode configurations.
- Measurement of valley polarization and exciton energy shifts.
- Analysis of temperature-dependent valley polarization.
Main Results:
- Ferroelectric gating strongly enhances room-temperature valley polarization in WS2.
- Carrier doping provides moderate alteration, while ferroelectric coupling induces Stark shifts and enhances polarization.
- Nonvolatile control of valley properties is demonstrated, persisting after gate voltage removal.
- Bilayer WS2 exhibits enhanced valley polarization due to intralayer-interlayer exciton transitions.
Conclusions:
- Ferroelectric gating offers effective electrical control over valley excitons in semiconductors.
- The interaction with ferroelectric materials significantly boosts valley polarization in WS2.
- This work paves the way for developing high-performance room-temperature valleytronics devices.
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