Coulomb Screening and Scattering in Atomically Thin Transistors across Dimensional Crossover

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Layered two-dimensional (2D) dichalcogenides are explored as alternatives to silicon in next-generation electronics.
• Understanding charge carrier behavior, particularly Coulomb screening and scattering, is crucial for optimizing their performance.

Purpose of the Study:

• To investigate the fundamental Coulomb screening and scattering effects in 2D dichalcogenides.
• To analyze the impact of electric permittivity, interaction distance, and impurity density on electron mobility.
• To clarify mobility discrepancies arising from permittivity changes during dimensional crossover.

Main Methods:

• Experimental and theoretical studies on dual-gated MoS2 transistors with asymmetric dielectric cleanliness.
• Synergic modulation of channel thicknesses and gating modes.
• Development of configurative form factors to analyze parametric changes across dimensional crossover.

Main Results:

• Systematic analysis of electron mobility trends with respect to Coulomb factors.
• Unfolded a comprehensive diagram of carrier scattering mechanisms, highlighting Coulomb scattering.
• Identified up to 40% mobility discrepancy due to permittivity modification across dimensional crossover.

Conclusions:

• Coulomb screening and scattering significantly influence electron mobility in 2D dichalcogenides.
• Permittivity changes during dimensional crossover lead to notable discrepancies in carrier mobility.
• This research provides insights for developing advanced atomically thin body transistors.