Thermal conductivity of single-layer MoS2: A comparative study between 1H and 1T′ phases

Highlights: • Lots of experimental and theoretical efforts have been devoted to studying the thermal transport in the hexagonal 1H phase of MoS₂. • However, besides the 1H phase, the trigonal 1T′ phase is another common structure for the MoS₂. • Furthermore, these two phases usually coexist in the experiment samples, as MoS₂ can transform between these two phases under proper phase-engineering techniques. • It is thus of practical significance to comparatively investigate the thermal conductivity of the 1T′ and 1H phases of MoS₂, as the thermal transport in the 1T′-MoS₂ is still unknown. We perform molecular dynamic simulations to investigate the thermal conductivity of Single-Layer 1H-MoS₂ (1H-SLMoS₂) and Single-Layer 1T′-MoS₂ (1T′-SLMoS₂), including the size, temperature, and strain effects. (1) For the size effect, the thermal conductivity of both 1H-SLMoS₂ and 1T′-SLMoS₂ increases with increasing length, while the thermal conductivity is insensitive to the width of the sample. The thermal conductivity of 1H-SLMoS₂ is slightly smaller than the 1T′-SLMoS₂ of the same size. (2) For the temperature effect, our simulation results show that the thermal conductivity of both 1H-SLMoS₂ and 1T′-SLMoS₂ decrease with increasing temperature. (3) For the strain effect, we find that the mechanical strain has different effects on the thermal conductivity of the 1H-SLMoS₂ and 1T′-SLMoS₂. More specifically, the thermal conductivity decreases with increasing tensile strain for 1T′-SLMoS₂, but the mechanical strain has weak effects on the thermal conductivity of the 1H-SLMoS₂.