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Low Solar Absorptance, High Emittance Performance Thermochromic VO2-Based Smart Radiator Device
1Physics Department, College of Science and General Studies, Alfaisal University, P.O. Box 50927, Riyadh 11533, Saudi Arabia.
Nanomaterials (Basel, Switzerland)
|December 23, 2022
Summary
Researchers developed a new coating for thermochromic vanadium dioxide (VO2) smart radiator devices (SRDs). This coating significantly reduces solar absorptance, making VO2 SRDs more suitable for spacecraft thermal control.
Area of Science:
- Materials Science
- Aerospace Engineering
- Optics
Background:
- Thermochromic vanadium dioxide (VO2) based smart radiator devices (SRDs) offer promising energy-efficient thermal control for spacecraft.
- A key limitation for VO2 SRDs is their high solar absorptance, hindering optimal performance in space applications.
Purpose of the Study:
- To reduce the solar absorptance of VO2-based SRDs without compromising their temperature-dependent emittance properties.
- To investigate the effectiveness of an additional multi-layer stack for solar absorptance reduction.
Main Methods:
- Combines optical simulation and experimental validation.
- Applies a top stack layer of alternating high and low refractive index materials (a-Si/SiO2).
- Evaluates changes in solar absorptance and emittance performance.
Main Results:
- Successfully reduced solar absorptance by 35% (from 0.43 to 0.28).
- Maintained required emittance performance: low-temperature emittance (εL) of 0.35, high-temperature emittance (εH) of 0.81, and tuneability (Δε) of 0.46.
- Demonstrated the viability of a-Si(25 nm)/SiO2(67 nm) as an effective top stack layer.
Conclusions:
- The developed multi-layer coating effectively lowers solar absorptance in VO2 SRDs.
- This advancement enhances the suitability of VO2 SRDs for spacecraft thermal management.
- Further design considerations for multi-layer stacks can optimize solar absorptance reduction.
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