Initial film layers prepared from tin(II) chloride spontaneously generate open cavities when the initial film layers are thermally cured to about 400 C. using a temperature ramp of 1 C./minute to 10 C./minute while exposed to air. The openings of the bowl-shaped cavities have characteristic dimensions whose lengths are in a range of 30 nm to 300 nm in the plane of the top surfaces of the cured film layers. The cured film layers comprise tin oxide and have utility in gas sensors, electrodes, photocells, and solar cells.

A light-transmitting structure is disclosed. The light-transmitting structure includes a glass-based substrate that has a first major surface and a second major surface opposite the first major surface. The glass-based substrate comprises a first composition that is transparent and has a first refractive index n.sub.1. The light-transmitting structure further includes a plurality of surface regions fused with the glass-based substrate to define a light-scattering surface interposed with the first major surface. Each surface region comprises a second composition that is transparent and has a second refractive index n.sub.2 that is different than the first refractive index n.sub.1. The first major surface and the light-scattering surface define an interface to an ambient environment.

A low-reflection coating of the present invention is a porous film including: fine silica particles being solid and spherical and having an average particle diameter of 80 to 150 nm; and a binder containing silica as a main component, the fine silica particles being bound together by the binder. The binder further contains an aluminum compound. The low-reflection coating contains, as components, 55 to 70 mass % of the fine silica particles, 25 to 40 mass % of the silica of the binder, and 2 to 7 mass % of the aluminum compound in terms of Al.sub.2O.sub.3. The low-reflection coating has a thickness of 80 to 800 nm. The low-reflection coating yields a transmittance gain of 2.5% or more when provided on the substrate. The transmittance gain represents an increase in average transmittance of the substrate provided with the low-reflection coating relative to the substrate not provided with the low-reflection coating, the average transmittance being measured in the wavelength range of 380 to 850 nm.