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Thickness-dependent decoupling charge transport and NH3sensing in multilayer MoS2transistors.
Yucheng Xiong1, Ying Pan1, Zhuan Cheng1
1Institute of Micro/Nano Electromechanical System and Integrated Circuit College of Mechanical Engineering, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Donghua University, Shanghai, People's Republic of China.
Nanotechnology
|June 29, 2026
Summary
The thickness of multilayer molybdenum disulfide (MoS₂) impacts both electrical transport and ammonia (NH₃) sensing. Thinner MoS₂ enhances sensing, while optimal thickness maximizes charge carrier mobility for electronic applications.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanoscience and Nanotechnology
Background:
- Thickness is a crucial factor influencing charge transport and surface reactivity in 2D semiconductors.
- Understanding thickness-dependent properties is vital for optimizing 2D material-based devices.
Purpose of the Study:
- To investigate the coupling between carrier transport and NH₃ sensing in multilayer MoS₂ as a function of thickness.
- To establish a framework for engineering the trade-off between transport efficiency and sensing sensitivity in MoS₂.
Main Methods:
- Fabrication and characterization of multilayer MoS₂ field-effect transistors with controlled layer numbers.
- Measurement of field-effect mobility and NH₃ sensing response across varying MoS₂ thicknesses.
- Analysis of scattering mechanisms and electrostatic screening effects.
Main Results:
- Field-effect mobility showed nonmonotonic behavior, peaking at ~21 layers, due to competing scattering and screening effects.
- NH₃ sensing response decreased monotonically with increasing thickness, with significant sensitivity observed in thinner films (6 layers).
- An inverse correlation between mobility and sensing response was observed, linked to surface adsorption and bulk transport decoupling.
Conclusions:
- Thickness is a critical design parameter for optimizing multilayer MoS₂ for both electronic and sensing applications.
- The study provides insights into the interplay between transport physics and surface charge-transfer modulation in 2D materials.
- Tailoring MoS₂ thickness allows for the engineering of a balance between device performance and sensitivity.
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