Inorganic oxide articles with thin, durable anti-reflective structures

An article comprising:

• an inorganic oxide substrate comprising opposing major surfaces;
• and
• an optical film structure disposed on a first major surface of the inorganic oxide substrate, the optical film structure comprising a physical thickness from about 50 nm to less than 325 nm, a plurality of alternating high index and low index layers with a first low index layer on the first major surface, and a capping low index layer,
• wherein the plurality of alternating high index and low index layers is at least four (4) layers, wherein each low index layer comprises a silicon-containing oxide and each high index layer comprises a silicon-containing nitride,
• wherein the optical thickness of the high index layer adjacent to the capping low index layer is from about 45 nm to about 450 nm, and the physical thickness of the capping low index layer is about 80 nm or more,
• wherein a refractive index of the low index layers is within a range of a refractive index of the substrate such that the refractive index of the low index layers is less than about 1.8, and wherein the high index layer comprises a refractive index that is greater than 1.8,
• wherein the high index layer exhibits a maximum hardness of 18 GPa or greater as measured by a Berkovich Indenter Hardness Test over an indentation depth from about 100 nm to about 500 nm on a hardness test stack comprising the high index layer with a physical thickness of about 2 microns disposed on the inorganic oxide substrate,
• wherein a combined physical thickness of the high index layers is about 35% or greater than the physical thickness of the optical film structure, and
• further wherein the article exhibits a single-side photopic average reflectance that is less than 1%.

An article comprising:

• an inorganic oxide substrate comprising opposing major surfaces;
• and
• an optical film structure disposed on a first major surface of the inorganic oxide substrate, the optical film structure comprising a physical thickness from about 50 nm to less than 325 nm, a plurality of alternating high index and low index layers with a first low index layer on the first major surface of the substrate, and a capping low index layer comprising a physical thickness of 80 nm or more,
• wherein each layer comprises one or more of a silicon-containing oxide, a silicon-containing nitride, and a silicon-containing oxynitride,
• wherein a refractive index of the low index layers is in a range of a refractive index of the inorganic oxide substrate such that the refractive index of the low index layers is less than about 1.8, and wherein the high index layer comprises a refractive index that is greater than 1.8,
• wherein a combined physical thickness of the high index layers is about 35% or greater than the physical thickness of the optical film structure, and
• further wherein the article exhibits a single-side photopic average reflectance that is less than 1%.

An article comprising:

• an inorganic oxide substrate comprising opposing major surfaces;
• and
• an optical film structure disposed on a first major surface of the inorganic oxide substrate, the optical film structure comprising a physical thickness from about 200 nm to less than 450 nm and one or more of a silicon-containing oxide, a silicon-containing nitride, and a silicon-containing oxynitride,
• wherein the optical film structure comprises a capping layer and a plurality of alternating high index and low index layers with a first low index layer on the first major surface of the substrate, the plurality of alternating high index and low index layers is four (4) layers or less, and further wherein each low index layer and capping layer is silicon dioxide and each high index layer is silicon nitride,
• wherein the capping layer has a physical thickness from 75 nm to 125 nm,
• wherein a combined physical thickness of the high index layers is about 35% or greater than the physical thickness of the optical film structure, and
• further wherein the article exhibits a single-side photopic average reflectance that is less than 0.9%.