Highly Efficient Electrode of Dirac Semimetal PtTe₂ for MoS₂-Based Field Effect Transistors

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) van der Waals (vdW) materials offer unique physical properties for quantum devices.
• Large Schottky barriers at metal-semiconductor interfaces hinder the performance of 2D material-based field-effect transistors (FETs).

Purpose of the Study:

• To investigate exfoliated vdW Dirac semimetallic PtTe₂ as a high-performance electrode for MoS₂ FETs.
• To address the limitations imposed by Schottky barriers in 2D material devices.

Main Methods:

• Fabrication of MoS₂ FETs using exfoliated PtTe₂ as an electrode.
• Characterization of FET performance, including mobility and on-off current ratio.
• Analysis of the metal-semiconductor interface using Raman spectroscopy to investigate orbital hybridization.

Main Results:

• Achieved high FET mobility of 85 cm² V⁻¹ s⁻¹ in MoS₂ FETs with PtTe₂ electrodes.
• Observed a negligibly small Schottky barrier height and an on-off current ratio exceeding 10⁸.
• Demonstrated good ohmic contact formation due to the orbital hybrid effect between PtTe₂ and MoS₂, evidenced by Raman spectra shifts.

Conclusions:

• Exfoliated Dirac semimetallic PtTe₂ is a highly effective electrode for MoS₂ FETs, significantly improving device performance.
• The findings offer a promising strategy for developing high-performance electrodes for various 2D vdW materials and quantum devices.