Modulating the phase transition between metallic and semiconducting single-layer MoS2 and WS2 through size effects

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Molybdenum disulfide (MoS2) and tungsten disulfide (WS2) are transition metal dichalcogenides with diverse electronic properties.
• Homo-junctions in these materials offer potential for novel electronic devices.
• Understanding the atomic mechanisms governing their electronic behavior is crucial for material design.

Purpose of the Study:

• To investigate the electronic properties and atomic mechanisms of single-layer MoS2 or WS2 homo-junctions.
• To explore the influence of boundary types and lateral size on the stability and electronic structure.
• To determine the feasibility of tuning phase transformations and electronic behavior.

Main Methods:

• First-principles calculations were employed to simulate and analyze the homo-junction structures.
• The study focused on the interplay between semiconducting hexagonal (H) and metallic trigonal (T) phases.
• The effect of varying nanoribbon size on phase transformation was examined.

Main Results:

• The stability and electronic structure of MoS2/WS2 homo-junctions are significantly influenced by boundary types connecting H and T phases.
• Tuning the lateral size of MoS2 or WS2 homo-junctions can induce phase transformations between H and T structures.
• The electronic properties of these homo-junctions can be controllably tuned between metallic and semiconducting states by adjusting nanoribbon size.

Conclusions:

• The atomic mechanism of single-layer MoS2/WS2 homo-junctions is sensitive to structural configurations.
• Lateral size is a critical parameter for controlling phase transitions and electronic properties in these materials.
• These findings provide insights for designing advanced electronic devices based on MoS2 and WS2 homo-junctions.