Strain-Driven Switchable Thermal Conductivity in Ferroelastic PdSe2.

Materials with either high or low lattice thermal conductivity are remarkable for thermal management with applying in high-power electronic, optoelectronic, and thermoelectric devices. The realization of thermal switch between high and low thermal conductivities can greatly promote the ability of thermal energy control. Here, based on first-principles calculations, we propose that ferroelastic PdSe2 can achieve continuous switchable thermal conductivity through strain-driven structural phase transition. Thermal switch we explored mainly stems from soft mechanical properties and strong anharmonicity of the structure after ferroelastic phase transition. We demonstrate that the maximum ratio of thermal switch can reach an order of magnitude, indicating PdSe2 as a promising candidate in thermal devices.