Fig. 5.

Schematic illustration of the multiple reflection and refraction occurred in the SiO₂ negative replicas and the reflectance spectroscopy analysis of the SiO₂ negative replica. a After multiple reflections and refractions, incident light traveled for a longer distance, and only a small part of the solar energy was reflected back to the air. b The average reflection of the SiO₂ negative replicas was about 20 % which was just 1/4 of the reflection of the flat plate without the negative quasi-honeycomb-like structure