Using Photonic Glasses as Colored Covers for Solar Energy Harvesting

The increasing demand for renewable energy is promoting technologies that integrate solar energy harvesting materials with the human living environment, such as building-integrated photovoltaics. This places requirements on developing colored covers with a trade-off between efficiency and aesthetics, providing a new stage for the large-scale application of structural color technologies. This study investigates the theoretic feasibility of employing the photonic glass, a random packing of monodisperse dielectric microspheres, as the colored cover for solar energy harvesting. Based on numerous optical simulations, the color and average solar transmissivity of the photonic glasses with varying parameters are evaluated. Results show that using non-absorbing microspheres with relatively high refractive index, about 3 mu m thick photonic glasses can enable colors with lightness over 50 while keeping average solar transmissivity over 80%. Due to the short-range structural correlation, it is demonstrated that photonic glasses can generate purple, blue, cyan, light green, and gray colors, but cannot help with yellow and red hues. Finally, the effects of several enhancement methods are clarified, and possible ways for expanding the color range are demonstrated. These results provide a comprehensive guide to the practical implementations of structural color using photonic glasses, particularly in the colorization of solar energy materials.