Tunable smart mid infrared thermal control emitter based on phase change material VO2 thin film

Abstract

Thermal radiation is one of the three ways of heat transfer, among which the mid-infrared thermal radiation has attracted much attention. At present, static control of thermal emissivity has been unable to meet the practical application, the device of dynamic control of thermal radiation is expected. In this paper, we study an intelligent thermal controlled radiation emitter based on a layered structure formed by phase change material Vanadium Dioxide. The transition denaturation of Vanadium Dioxide can realize the switching process from heat dissipation at high temperature to heat preservation at low temperature. In the mid-infrared wavelength range of 5–13 μm, significant differences in emission characteristics are observed due to variations in the imaginary part of the dielectric constant of Vanadium Dioxide. When it is in the high temperature metallic state, the optimal structural parameters, from top to bottom, are 10 nm, 350 nm, 320 nm, and 200 nm. With these parameters, the structure exhibits an emissivity of 0.78 and a full width at half maximum of 8.03 μm. This configuration achieves effective thermal radiation dissipation, as governed by the Stefan-Boltzmann’s law. On the other hand, when the structure is in the low temperature dielectric state, it exhibits a low absorption effect with an emissivity of 0.10, thus avoiding excessive heat loss. The radiative modulation capability and thermal stability were achieved through the use of thermochromic material Vanadium Dioxide which exhibits temperature switchable behavior. Additionally, the thermal control emitter, utilizing its resonant cavity, enables tunability of peak wavelength and demonstrates a certain degree of independence with respect to polarization and incident angle. The designed emitter structure is simple and easy to fabricate, holding significant prospects for applications in engineering insulation materials, infrared camouflage, and thermal management.