Emerging Solid–State Thermal Switching Materials

Growing technical demand for thermal management stems from the pursuit of high-efficient energy utilization and the reuse of wasted thermal energy, which necessitates the manipulation of heat flow with electronic analogs to improve device performance. Here, recent experimental progress is reviewed for thermal switching materials, aiming to achieve all-solid-state thermal switches, which are an enabling technology for solid-state thermal circuits. Moreover, the current understanding for discovering thermal switching materials is reshaped from the aspect of heat conduction mechanisms under external controls. Furthermore, current challenges and future perspectives are provided to highlight new and emerging directions for materials discovery in this continuously evolving field. Thermal switching materials can switch between low (OFF-state) and high (ON-state) thermal conductivity states driven by an external trigger. They are expected to enable switching functions essential for developing thermal logic circuits. This review classifies numerous reported thermal switching materials into four categories (individual tuning or combined tuning) based on the three main heat carriers: charge carriers, phonons, and magnetic excitations in solid materials.image