Thermochromic VO2 based sandwich structure Ag/Al2O3/VO2 with low solar absorption and tunable emittance for spacecraft
Xiaoqian Wang, Haibo Jin, Boyu Wang, Chen Ling, Junlin Yang, Donglai Li, Jingbo Li
Abstract
The smart radiator device (SRD) with low solar absorption (αs) and large infrared emittance modulation (Δɛ) is desirable to a spacecraft thermal control system. In this work, the SRD was fabricated through depositing the Ag/Al2O3/VO2 triple-layer film on the Si substrate by magnetron sputtering. The properties of the SRD devices were optimized by tuning the thickness of the VO2 layer, and a fantastic SRD device was acquired, which showed low αs, high Δɛ, and intense high-temperature infrared emittance (ɛHT). For the device with a VO2 layer of 50 nm thickness, αs was as low as 29.7% and Δɛ reached 0.53 with ɛHT up to 0.87. The triple-layer film device shows great potential for applications in the spacecraft thermal control system.