Anti-reflective and high-transmittance optical films based on nanoporous silicon dioxide fabricated from templated synthesis

Herein, we report anti-reflective and high-transmittance optical films based on nanoporous silicon dioxide (SiO2) fabricated from templated synthesis. Amorphous mesoporous polystyrene (PS) thin-film templates were prepared by solvent nano-crystallization induced phase separation technique. The mesoporous PS films were used as templates for the preparation of nanoporous SiO2 thin films through the sol-gel method followed by the removal of the template at high temperatures. The nanoporous SiO2 thin films were well-characterized by Field-Emission Scanning Electron Microscopy (FE-SEM), and N2 sorption isotherms for framework size, morphology, surface area, and pore volume respectively. The average pore size for disordered nanoporous SiO2 and calculated porosities are 23 nm and 0.60 respectively. The amorphous nanoporous SiO2 was evaluated for optical reflectance and transmittance in the visible light spectrum and found to have reflectance as low as 6.9% and transmittance as high as 96.5%.