Design of the High-Performance All-Polymer Solar Reflector via Genetic Optimization

The Optical Solar Reflector (OSR) is a spectrally selective filtering device that is crucial for managing and harnessing solar energy efficiently. Most of the existing OSRs are based on metals and typically require additional protective layers to enhance their durability. An all-polymer solar reflector can leverage the intrinsic advantages of polymeric materials, such as design versatility, corrosion resistance, etc. However, developing an all-polymer solar reflector poses great challenges due to the inherently small refractive index contrast among polymeric materials. In this work, we design an all-polymer solar reflector by stacking multiple layers of polydimethylsiloxane (PDMS) and poly(ether imide) (PEI) with varying thicknesses. We address the challenge through a specialized chromosome design and a rationally selected objective function for genetic algorithms, which are applied to optimize the solar reflectivity while constraining the total number of polymer layers. The optimized all-polymer optical solar reflector comprises 594 layers with a total thickness of 108 μm and exhibits a solar-weighted reflectance up to 97.2% in the solar spectrum region (0.3–2.5 μm). This work paves the way for fully polymeric solar reflector systems with enhanced durability and versatility compared with their metal-based counterparts.