Thermal Rectifier and Thermal Transistor of 1T/2H MoS₂ for Heat Flow Management

Thermal rectifiers and thermal transistors are expected to be widely used for efficient thermal management and energy cascade utilization due to their excellent directional thermal management. Two-dimensional micro/nano materials have huge potential in the applications of thermal transistors, thermal logic circuits, and thermal rectifiers owing to the phase transition and thermal rectification phenomenon. Herein, a lithium intercalation method was used to transform 2H-MoS₂ into the 1T phase with a purity of 76%, and a suspended microelectrode was applied to measure the thermal conductivity and thermal rectification coefficient of the same MoS₂ film with 1T and 2H phases in suit. The thermal conductivity and thermal rectification effect of two-phase MoS₂ couple with its phase state and structure were also obtained. The results demonstrate that the thermal conductivities of MoS₂ in both 1T and 2H phases decrease with increasing temperature. It is also found that the thermal rectification coefficient has no obvious dependence on the temperature and phase change but the asymmetric structure. Furthermore, a thermal rectifier and transistor with a high thermal rectification effect are designed. The direction and magnitude of heat flow through the samples can be effectively controlled and managed by adjusting the phase, size, and structural asymmetry of the different samples. The maximum thermal rectification coefficient of the thermal rectifiers is up to 0.8.