NOVELTY - Preparation of antireflective coating for deposition on a substrate involves forming a combined sol gel by mixing silane with solvent, catalyst, water, colloidal silica and metal oxide; casting the combined sol gel to form a layer on the substrate; and curing and/or heat treating the layer.    USE - For the preparation of antireflective coating for deposition on a substrate such as photovoltaic device (claimed) including solar cell, storefront windows, display cases, picture frames, other types of windows.    ADVANTAGE - The porous silica coatings have high transmittance, thus improves the efficiency and/or power of the photovoltaic device; also have improved scratch resistance; and reduces reflection of light from the glass substrate, and allows more light within the solar spectrum to pass through the incident glass substrate and reach the photovoltaic semiconductor so that the solar cell can be more efficient.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) preparation of photovoltaic device including an anti-reflection coating involving forming a polymeric component of silica by mixing at least one silane with at least a first solvent, first catalyst and water; mixing the polymeric component with a colloidal silica and second solvent to form a silica sol; forming a metal oxide sol by mixing silane with a metal oxide, second catalyst, and third solvent; forming a combined sol gel by mixing the silica sol with the metal oxide sol; casting the combined sol gel to form a layer on a glass substrate; and curing and/or heat treating the layer, and using the layer in at least part of an antireflective film on the glass substrate in a photovoltaic device; and    (2) a photovoltaic device comprising a photovoltaic film, and at least a glass substrate on a light incident side of the photovoltaic film; an anti-reflection coating provided on the glass substrate. The anti-reflection coating comprises at least a layer provided directly on and contacting the glass substrate, where the layer comprises porous silica and metal oxide.