Interfacial electronic properties between PtSe₂ and 2D metal electrodes: a first-principles simulation

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Monolayer (ML) PtSe2 is a 2D semiconductor with potential for electronic devices due to its band gap and carrier mobility.
• The performance of PtSe2 field-effect transistors (FETs) heavily relies on the selection of suitable metal electrodes for optimal interfacial properties.

Purpose of the Study:

• To systematically investigate the interfacial electronic properties between ML PtSe2 and various 2D metal electrodes.
• To identify suitable electrode materials for fabricating high-performance PtSe2-based FETs by analyzing contact types and Schottky barrier heights (SBHs).

Main Methods:

• Utilized a series of 2D metals, transition metal dichalcogenides (NbSe2, TaS2), borophene, and MXenes as potential electrodes.
• Employed ab initio calculations to study interfacial electronic properties in both vertical and lateral directions.
• Analyzed the formation of ohmic and Schottky contacts, including p-type and n-type, and quantified their respective SBHs.

Main Results:

• Most 2D metal electrodes formed ohmic contacts with ML PtSe2 in the vertical direction, with exceptions like Nb2CF2 and Hf2CF2 forming Schottky contacts.
• In the lateral direction, specific electrodes like Hf2CF2, V2C(OH)2, TaS2, and Nb2CF2 formed n-type or p-type Schottky contacts with varying SBHs.
• Ohmic contacts were observed with electrodes such as Hf2C(OH)2, Nb2C(OH)2 (n-type), and borophene, NbSe2, Nb2CO2, V2CF2 (p-type).

Conclusions:

• This study provides a comprehensive understanding of ML PtSe2 interfaces with diverse 2D metal electrodes.
• The findings offer a practical guide for selecting appropriate electrode materials to optimize the performance of PtSe2 FETs.