Charge doping induced thermal switches with a high switching ratio in monolayer MoS₂

The thermal switch plays a crucial role in regulating system temperature, protecting devices from overheating, and improving energy efficiency. Achieving a high thermal switching ratio is essential for its practical application. In this study, by utilizing first-principles calculations and semi-classical Boltzmann transport theory, it is found that hole doping with an experimentally achievable concentration of 1.83 × 10¹⁴ cm⁻² can reduce the lattice thermal conductivity of monolayer MoS₂ from 151.79 W⋅m⁻¹⋅K⁻¹ to 12.19 W⋅m⁻¹⋅K⁻¹, achieving a high thermal switching ratio of 12.5. The achieved switching ratio significantly surpasses previously reported values, including those achieved by extreme strain methods. This phenomenon mainly arises from the enhanced lattice anharmonicity, which is primarily contributed by the S atoms. These results indicate that hole doping is an effective method for tuning the lattice thermal conductivity of materials, and demonstrate that monolayer MoS₂ is a potential candidate material for thermal switches.