摘要
We report the synthesis and characterization of two-dimensional high-entropy transition metal dichalcogenides (2D HETMDs), specifically (MoWVNbTa)S2, alongside WS2 and (MoWV)S2, using NaCl-assisted chemical vapor deposition (CVD). The structural, optical, electrical, and thermal properties of these materials were investigated. (MoWVNbTa)S2 exhibits a single-crystal 2H-phase structure with uniform elemental distribution. Raman and photoluminescence spectroscopy reveal tunable band gaps [∼1.87 eV] and enhanced p-type characteristics due to Group V element doping [V, Nb, and Ta]. X-ray photoelectron spectroscopy confirms complete elemental incorporation at 900 °C, achieving a configurational entropy of ∼1.3R, which enhances thermodynamic stability. Electrical measurements demonstrate a transition from n-type to p-type and semi-metallic behavior, with the latter showing high conductivity but limited gate modulation. Thermal stability tests indicate (MoWVNbTa)S2 remains stable up to 650 °C, surpassing WS2 and (MoWV)S2, attributed to entropy-driven lattice cohesion. In-situ STEM at 600–800 °C reveals decomposition kinetics, with an activation energy of 0.57 eV, highlighting preferential decomposition along (010), (100), and (1̅10) planes and localized interlayer sliding. This work establishes a scalable approach for synthesizing high-entropy 2D TMDs, offering tunable electronic properties and enhanced thermal stability for next-generation electronic and optoelectronic applications.
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•NaCl-assisted CVD enables scalable synthesis of high-entropy (MoWVNbTa)S2 with ∼1.3R configurational entropy.•Group V doping tunes band gap and shifts WS2 from n-type to p-type and semi-metallic behavior.•(MoWVNbTa)S2 shows enhanced thermal stability up to 650 °C due to entropy-driven lattice cohesion.