P-type doping in 2M-WS₂ for a complete phase diagram.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid-State Chemistry

Background:

• 2D transition metal dichalcogenides (TMDs) like 2M-WS2 exhibit unique superconducting and topological properties.
• While n-type doping effects on 2M-WS2 superconductivity are known, p-type doping remains unexplored due to experimental challenges.
• Metastable 2M-WS2 phases are difficult to dope p-type, limiting research into their electronic behavior.

Purpose of the Study:

• To achieve p-type doping in 2M-WS2 for the first time.
• To investigate the impact of p-type doping on the superconducting properties of 2M-WS2.
• To establish a comprehensive phase diagram relating carrier concentration and superconductivity in 2M-WS2.

Main Methods:

• P-type doping of 2M-WS2 was successfully implemented using Molybdenum (Mo) as a dopant.
• The study systematically varied Mo content in W1-xMoxS2 samples.
• Superconducting transition temperature (Tc) and carrier concentration were measured as a function of Mo doping levels.

Main Results:

• Carrier concentration increased slightly from 1.42 × 10^21 cm^-1 to 1.56 × 10^21 cm^-1 with increasing Mo content.
• Superconducting transition temperature (Tc) decreased monotonically with rising Mo doping.
• A minimum Tc of 4.37 K was observed at the doping limit of x = 0.6 in W1-xMoxS2.

Conclusions:

• The successful p-type doping of 2M-WS2 using Mo opens new avenues for exploring its electronic properties.
• A phase diagram illustrating the relationship between carrier concentration and Tc exhibits a typical dome-like shape, consistent with established theories for related materials.
• These findings provide crucial insights into the interplay between doping, carrier concentration, and superconductivity in 2M-WS2, advancing the understanding of this novel material.