Broadband antireflective glasses with subwavelength structures using randomly distributed Ag nanoparticles.

We demonstrate broadband antireflective glasses with subwavelength structures (SWSs) using randomly distributed Ag nanoparticles. Ag nanoparticles formed by a thermal dewetting process were used as an etch mask for dry etching to fabricate antireflective SWSs on the glass surface. The size and shape of Ag nanoparticles are changed by the different thickness of the Ag thin film. The morphology of SWSs fabricated by using the Ag thin films is well consistent with that of the Ag nanoparticles. The single-side SWS integrated glass exhibits improved transmittance of approximately 96% at 750 nm due to the graded refractive index profiles, while the transmittance is only approximately 92.5% for the flat surface. To reduce Fresnel reflection at the other side of the glass substrate, the SWSs with optimized Ag film thickness and dry etching conditions are formed on both sides of the glass. The dual-side SWS integrated glass show an average transmittance of approximately 97.5% in a wavelength range of 350-750 nm. Transmission band shrinkage effects of the SWS integrated glass are also observed with increased average size of the Ag nanoparticles.