A novel trilayer antireflection coating using dip-coating technique

Abstract

We report a new structure for broadband antireflection coating by dip-coating technique, which has minimal cost and is compatible with large-scale manufacturing. The coatings are prepared by depositing SiO2 sol-gel film on a glass substrate, subsequently depositing SiO2 single-layer particle coating through electrostatic attraction, and depositing a final very thin SiO2 sol-gel film to improve the mechanical strength of the whole coating structure. The refractive index of the structure changes gradually from the top to the substrate. The transmittance of a glass substrate has been experimentally found to be improved in the spectral range of 400-1,400 nm and in the incidence angle range from 0o to at least 45o. The mechanical strength is immensely improved because of the additional thin SiO2 sol-gel layer. The surface texture can be applied to the substrates of different materials and shapes as an add-on coating.