As a technology without requiring any energy consumption, radiative cooling has the potential to be applied in the field of electronic device cooling. To improve the cooling efficiency, studies mainly focuses on improving the solar reflectivity and infrared emissivity of materials. However, it is more applicable when the temperature of electronic devices is higher than that of the environment. To ensure the high cooling power at different temperatures, this study focuses on the influence of emissivity in different wavelength. It is found that under high temperature conditions, the cooling efficiency of the full-band (3-25 μm) non-selective high emissivity structure is the highest. On the contrary, the dual-band (8-13 and 16-25 μm) high emissivity structure exhibits the best performance. Based on the above results, it can be concluded that the static thermal emissivity is unable to meet the requirements of practical applications. Therefore, a multilayer structure with temperature adaptive emissivity is designed based on the phase transition material W-doped VO₂. It is composed of alternating layers of VO₂, Si₃N₄, TiO₂, CaF₂ and SiO₂, and the parameters are optimized via the transfer matrix method. The results show that at high temperature, the structure has high emissivity across the entire wavelength range, with an average value of 0.82. At low temperature, the dual-band emissivity is 0.87, while the emissivity in other wavelength range decreases to 0.42. Meanwhile, the structure has high solar reflectivity over 0.93 at different temperatures. This design achieves superior cooling performance under various conditions, providing a comprehensive and reliable radiative cooling solution for the thermal management of electronic devices.

Phase change material, radiative cooling, thermal management, vanadium dioxide