Applied Nanophotonics, Liquid Crystals and Biomedical Optics

This study presents a novel approach towards achieving high luminous transmittance (T_lum) for vanadium dioxide (VO₂) thermochromic nanogrid films whilst maintaining the solar modulation ability (ΔT_sol). The perforated VO₂-based films employ orderly-patterned nano-holes, which are able to favorably transmit visible light dramatically but retain large near-infrared modulation, thereby enhancing ΔT_sol. Numerical optimizations using parameter search algorithms have implemented through a series of Finite Difference Time Domain (FDTD) simulations by varying film thickness, cell periodicity, grid dimensions and variations of grid arrangement. The best performing results of T_lum (76.5%) and ΔT_sol (14.0%) are comparable, if not superior, to the results calculated from nanothermochromism, nanoporosity and biomimic nanostructuring. It opens up a new approach for thermochromic smart window applications.