Computational Search for Two-Dimensional MX2 Semiconductors with Possible High Electron Mobility at Room Temperature

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanoscience

Background:

• Graphene and single-layer Molybdenum Disulfide (MoS2) are insufficient for advanced semiconductor logic devices.
• Novel two-dimensional (2D) materials are needed to overcome limitations of current semiconductor technologies.

Purpose of the Study:

• To computationally screen 14 transition metal dichalcogenides (MX2) for potential use in semiconductor logic devices.
• To identify 2D materials with high electron mobility and suitable electronic properties.

Main Methods:

• Calculated electron mobility using deformation potentials and included electron-phonon scattering (longitudinal acoustical and optical phonons).
• Accounted for piezoelectric scattering in materials lacking inversion symmetry.
• Employed local density approximation for electronic structure calculations.

Main Results:

• Identified Tungsten Disulfide (WS2), Platinum Disulfide (PtS2), and Platinum Diselenide (PtSe2) as promising candidates.
• PtSe2 exhibited the highest phonon-limited electron mobility (~4000 cm^2·V^-1·s^-1) at room temperature.
• PtSe2 possesses a suitable indirect bandgap (~1.25 eV).

Conclusions:

• WS2, PtS2, and PtSe2 demonstrate significant potential for next-generation semiconductor logic devices.
• PtSe2 stands out due to its exceptionally high electron mobility and appropriate bandgap.
• These findings provide experimental guidance for synthesizing advanced 2D semiconductor materials.