An ultraviolet light emitting device comprises: a first substrate having a main surface; a second substrate facing the main surface of the first substrate; a gas in a space between the first substrate and the second substrate; electrodes directly or indirectly on the main surface of the first substrate; a dielectric layer that is located directly or indirectly on the main surface of the first substrate and covers the electrodes; and a first light-emitting layer. The first light-emitting layer is located directly or indirectly on the dielectric layer and emits ultraviolet light in the gas due to electrical discharge between the electrodes. The first light-emitting layer is thicker in first regions on the dielectric layer than in second regions. The second regions include at least part of regions directly above the electrodes.

Microstructured, irregular surfaces pose special challenges but coatings of the invention can uniformly coat irregular and microstructured surfaces with one or more thin layers of phosphor. Preferred embodiment coatings are used in microcavity plasma devices and the substrate is, for example, a device electrode with a patterned and microstructured dielectric surface. A method for forming a thin encapsulated phosphor coating of the invention applies a uniform paste of metal or polymer layer to the substrate. In another embodiment, a low temperature melting point metal is deposited on the substrate. Polymer particles are deposited on a metal layer, or a mixture of a phosphor particles and a solvent are deposited onto the uniform glass, metal or polymer layer. Sequential soft and hard baking with temperatures controlled to drive off the solvent will then soften or melt the lowest melting point constituents of the glass, metal or polymer layer, partially or fully embed the phosphor particles into glass, polymer, or metal layers, which partially or fully encapsulate the phosphor particles and/or serve to anchor the particles to a surface.

Microstructured, irregular surfaces pose special challenges but coatings of the invention can uniformly coat irregular and microstructured surfaces with one or more thin layers of phosphor. Preferred embodiment coatings are used in microcavity plasma devices and the substrate is, for example, a device electrode with a patterned and microstructured dielectric surface. A method for forming a thin encapsulated phosphor coating of the invention applies a uniform paste of metal or polymer layer to the substrate. In another embodiment, a low temperature melting point metal is deposited on the substrate. Polymer particles are deposited on a metal layer, or a mixture of a phosphor particles and a solvent are deposited onto the uniform glass, metal or polymer layer. Sequential soft and hard baking with temperatures controlled to drive off the solvent will then soften or melt the lowest melting point constituents of the glass, metal or polymer layer, partially or fully embed the phosphor particles into glass, polymer, or metal layers, which partially or fully encapsulate the phosphor particles and/or serve to anchor the particles to a surface.

Coating systems suitable for use in generating fluorescent visible light, and lamps provided with such coating systems. The coating systems includes a phosphor-containing coating that contains at least a first phosphor that is predominantly excited by ultraviolet radiation of a first wavelength to emit visible light and absorbs but is less efficiently excited by ultraviolet radiation of a second wavelength. The coating system further includes a second phosphor that absorbs the ultraviolet radiation of the second wavelength and little if any of the ultraviolet radiation of the first wavelength.

Coating systems suitable for use in generating fluorescent visible light, and lamps provided with such coating systems. The coating systems includes a phosphor-containing coating that contains at least a first phosphor that is predominantly excited by ultraviolet radiation of a first wavelength to emit visible light and absorbs but is less efficiently excited by ultraviolet radiation of a second wavelength. The coating system further includes a second phosphor that absorbs the ultraviolet radiation of the second wavelength and little if any of the ultraviolet radiation of the first wavelength.

A novel type of green luminophore containing mixed rare-earth phosphates is produced from precursor particles having a mean diameter ranging from 1.5 to 15 microns; such particles have an inorganic core and a shell of a mixed lanthanum and/or cerium phosphate, optionally doped with terbium, evenly covering the inorganic core with a thickness greater than or equal to 300 nm.

A novel type of green luminophore containing mixed rare-earth phosphates is produced from precursor particles having a mean diameter ranging from 1.5 to 15 microns; such particles have an inorganic core and a shell of a mixed lanthanum and/or cerium phosphate, optionally doped with terbium, evenly covering the inorganic core with a thickness greater than or equal to 300 nm.

A phosphor material is presented that includes a blend of a first phosphor, a second phosphor and a third phosphor. The first phosphor includes a composition having a general formula of RE.sub.2yM.sub.1+yA.sub.2ySc.sub.ySi.sub.nwGe.sub.wO.sub.12+:Ce.sup.3+ wherein RE is selected from a lanthanide ion or Y.sup.3+, where M is selected from Mg, Ca, Sr or Ba, A is selected from Mg or Zn and where 0y2, 2.5n3.5, 0w1, and 1.51.5. The second phosphor includes a complex fluoride doped with manganese (Mn.sup.4+), and the third phosphor include a phosphor composition having an emission peak in a range from about 520 nanometers to about 680 nanometers. A lighting apparatus including such a phosphor material is also presented. The light apparatus includes a light source in addition to the phosphor material.

A phosphor material is presented that includes a blend of a first phosphor, a second phosphor and a third phosphor. The first phosphor includes a composition having a general formula of RE.sub.2yM.sub.1+yA.sub.2ySc.sub.ySi.sub.nwGe.sub.wO.sub.12+:Ce.sup.3+ wherein RE is selected from a lanthanide ion or Y.sup.3+, where M is selected from Mg, Ca, Sr or Ba, A is selected from Mg or Zn and where 0y2, 2.5n3.5, 0w1, and 1.51.5. The second phosphor includes a complex fluoride doped with manganese (Mn.sup.4+), and the third phosphor include a phosphor composition having an emission peak in a range from about 520 nanometers to about 680 nanometers. A lighting apparatus including such a phosphor material is also presented. The light apparatus includes a light source in addition to the phosphor material.

In different embodiments, a low-pressure discharge lamp (1) is provided. The low-pressure discharge lamp has a discharge vessel (2) and a coating structure (7). The coating structure is formed on an inner face of the discharge vessel (2). The coating structure (7) has first fluorescent particles (34) which have at least one fluorescent substance that emits red light and the average particle size of which ranges from 0.5 m to 1.9 m, second fluorescent particles (36) which have at least one fluorescent substance that emits green light and the average particle size of which ranges from 0.6 m to 2.8 m or from 1 m to 4 m, and third fluorescent particles (38) which have at least one fluorescent substance that emits blue light and the average particle size of which ranges from 1 m to 4 m.