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Layer-Dependent Chemically Induced Phase Transition of Two-Dimensional MoS2
Lifei Sun1, Xingxu Yan2,3, Jingying Zheng1
1Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry , Tsinghua University , Beijing 100084 , China.
Nano Letters
|May 22, 2018
Summary
The layer-dependent chemical phase transition of molybdenum disulfide (MoS2) was explored. Thinner MoS2 requires more electron doping and time to transition, impacting electronic device fabrication.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Two-dimensional (2D) transition metal dichalcogenides (TMDCs) exhibit unique properties influenced by their layered structure.
- The impact of layer number on the chemical properties of 2D TMDCs, particularly molybdenum disulfide (MoS2), is not well understood.
Purpose of the Study:
- To investigate the chemically induced phase transition of 2D MoS2.
- To understand how the number of layers affects this phase transition and its underlying mechanisms.
- To explore the potential applications of layer-dependent phase transitions in electronic devices.
Main Methods:
- Experimental investigation of MoS2 phase transitions.
- Theoretical calculations to elucidate the electronic structure and phase stability.
- Analysis of layer-dependent density of states.
Main Results:
- The critical electron injection concentration and transition duration for MoS2 increase as the number of layers decreases.
- Phase stability of 2H-MoS2 decreases with increasing layer number upon electron doping.
- Monolayer MoS2 exhibits a higher energy barrier for phase transition, leading to longer reaction times.
Conclusions:
- The electronic structure, specifically the layer-dependent density of states, governs the chemical properties and phase transition behavior of 2D MoS2.
- Layer-dependent phase transitions enable the creation of heterophase junctions for fabricating advanced 2D electronic devices like diodes and field-effect transistors.
- This research provides insights into controllable chemical modulation of 2D TMDCs based on their electronic structures.
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