Thermal management broadband-emitting device based on VO ₂ applied in the mid-infrared band

Mid-infrared thermal radiation has attracted attention due to its wide range of applications. Compared to the static process of thermal emission, if thermal radiation can be dynamically controlled, it would be more suitable for practical applications. Herein, we designed a controllable thermal emitter based on phase change materials. When the temperature changes from low to high, VO₂ transitions from a dielectric state to a metallic state, and its imaginary part of the dielectric constant significantly increases, leading to differences in emission characteristics. At low temperatures, the device is in a low dielectric state and resonates weakly with incident light. The main emission comes from the bottom of the grating structure, with an emissivity of 0.21. At high temperatures, the structure is in a high dielectric state, and multiple resonance modes are excited within the structure, such as cavity resonance and surface plasmon resonance, which increases the emissivity to 0.95 and achieves effective heat dissipation. Given its superior thermal management capabilities and stability, this design holds promise for applications in thermal imaging, infrared communication, and energy-efficient devices.