Transparent smart radiation device for efficient thermal management of spacecraft solar cells

In space, spacecraft face extreme temperature fluctuations that threaten their performance and stability. Variable emissivity coatings offer an effective solution for radiative thermal management. However, balancing high visual transparency with thermal radiation control remains a significant challenge, especially for applications like spacecraft solar cells. In this study, we propose a multilayer planar transparent smart radiation device (TSRD) based on thermochromic material, thin metal and indium tin oxide (ITO). The effect of different substrates on TSRD performance is systematically investigated. Balancing the performance of TSRD across various spectral bands, the VO₂/BaF₂/ITO/Ag/ITO structure demonstrates superior performance among the three cases. Specifically, it achieves transmission of 0.8 and 0.72 in the visible spectrum under high- and low-temperature conditions, respectively, a solar absorption of only 0.16, and an emission modulation of up to 0.51 in the infrared band. Moreover, the addition of a lossless dielectric layer as a protective coating not only preserves the excellent performance of the TSRD but also holds the potential to enhance its durability and lifespan. This work provides a promising strategy for multispectral modulation and offers an effective solution for spacecraft solar cells thermal management.