The present invention is directed to compositions comprising at least one layer or at least two layers, each layer comprising a substantially two-dimensional array of crystal cells, having first and second surfaces, each crystal cell having the empirical formula of M.sub.n+1X.sub.n, where M, X, and n are described in the specification, and devices incorporating these compositions.

There are provided a phosphor which is a divalent europium-activated oxynitride phosphor substantially represented by General formula (A): Eu.sub.aSi.sub.bAl.sub.cO.sub.dN.sub.e, a divalent europium-activated oxynitride phosphor substantially represented by General formula (B): MI.sub.fEu.sub.gSi.sub.hAl.sub.kO.sub.mN.sub.n or a divalent europium-activated nitride phosphor substantially represented by General formula (C): (MII.sub.1pEu.sub.p)MIIISiN.sub.3, having a reflectance of light emission in a longer wavelength region of visible light than a peak wavelength of 95% or larger, and a method of producing such phosphor; a nitride phosphor and an oxynitride phosphor which emit light efficiently and stably by the light having a wavelength ranging from 430 to 480 nm from a semiconductor light emitting device by means of a light emitting apparatus using such phosphor, and a producing method of such phosphor; and a light emitting apparatus having stable characteristics and realizing high efficiency.

The present invention is directed to crystalline solids having an empirical formula of M.sub.2A.sub.2X, wherein M is at least one Group IIIB, IVB, VB, or VIB metal, preferably Cr, Hf, Sc, Ti, Mo, Nb, Ta, V, Zr, or a combination thereof; wherein A is Al, Ga, Ge, In, Pb, or Sn, or a combination thereof; and each X is C.sub.xN.sub.y, where x+y=1. In some particular embodiments, the crystalline composition has a unit cell stoichiometry of Mo.sub.2Ga.sub.2C.

There are provided a phosphor which is a divalent europium-activated oxynitride phosphor substantially represented by General formula (A): Eu.sub.aSi.sub.bAl.sub.cO.sub.dN.sub.e, a divalent europium-activated oxynitride phosphor substantially represented by General formula (B): MI.sub.fEu.sub.gSi.sub.hAl.sub.kO.sub.mN.sub.n or a divalent europium-activated nitride phosphor substantially represented by General formula (C): (MII.sub.1-pEu.sub.p)MIIISiN.sub.3, having a reflectance of light emission in a longer wavelength region of visible light than a peak wavelength of 95% or larger, and a method of producing such phosphor; a nitride phosphor and an oxynitride phosphor which emit light efficiently and stably by the light having a wavelength ranging from 430 to 480 nm from a semiconductor light emitting device by means of a light emitting apparatus using such phosphor, and a producing method of such phosphor; and a light emitting apparatus having stable characteristics and realizing high efficiency.

In a method for sputter depositing an additive-containing aluminium nitride film containing an additive element like Sc or Y, a first layer of the additive-containing aluminium nitride film is deposited onto a substrate disposed within a chamber by pulsed DC reactive sputtering. A second layer of the additive-containing aluminium nitride film is deposited onto the first layer by pulsed DC reactive sputtering. The second layer has the same composition as the first layer. A gas or gaseous mixture is introduced into the chamber when depositing the first layer. A gaseous mixture comprising nitrogen gas and an inert gas is introduced into the chamber when depositing the second layer. The percentage of nitrogen gas in the flow rate (in sccm) when depositing the first layer is greater than that when depositing the second layer.

A method for producing a ceramic sintered body includes: preparing a molded body containing a nitride fluorescent material having the composition containing Si; N; at least one alkaline earth metal element M.sup.1; and a metal element M.sup.2 being at least one selected from the group consisting of Eu, Ce, Tb, and Mn, to obtain a composition as described in the disclosure; obtaining a first sintered body by performing primary calcination of the molded body; obtaining a second sintered body by performing secondary calcination of the first sintered body in contact with a solid composed of a molybdenum metal or an alloy containing molybdenum as a main component; and obtaining a third sintered body by performing third calcination of the second sintered body while being placed in a container containing a metal having a melting point higher than that of the molybdenum metal.

Phosphors include a CaAlSiN.sub.3 family crystal phase, wherein the CaAlSiN.sub.3 family crystal phase comprises at least one element selected from the group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb.

Preparing MAX phase structures includes forming a gel including a transition metal M, a Group 3A or Group 4A metal or semimetal A, and an acidic chelating agent or gelling agent X. X includes one or both of carbon and nitrogen. Preparing the MAX phase structures further includes shaping the gel to yield a shaped gel and heating the shaped gel to yield carbonaceous MAX phase structures with a composition represented by M.sub.n+1AX.sub.n, wherein n is 1, 2, 3, or 4. The MAX phase structures can be thick films, microspheres, or microwires.

A phosphor includes a nitride including an alkaline-earth metal element, silicon, and an activator element, wherein the phosphor has a volume average particle diameter ranging from about 50 nm to about 400 nm, and an internal quantum efficiency of greater than or equal to about 60% at an excitation wavelength of 450 nm, the phosphor is represented by a formula M.sub.2Si.sub.5N.sub.8, the M includes one or more alkaline-earth metal element selected from Ca, Sr, Ba, and Mg and including at least Sr, and one or more activator element selected from Eu and Ce and including at least Eu, an amount of the Sr included in the phosphor is about 15 mol % to about 99 mol % based on total moles of the M, and an amount of the activator element included in the phosphor is about 1 mol % to 20 mol % based on the total moles of the M.

There are provided a phosphor which is a divalent europium-activated oxynitride phosphor substantially represented by General formula (A): Eu.sub.aSi.sub.bAl.sub.cO.sub.dN.sub.e, a divalent europium-activated oxynitride phosphor substantially represented by General formula (B): MI.sub.fEu.sub.gSi.sub.hAl.sub.kO.sub.mN.sub.n or a divalent europium-activated nitride phosphor substantially represented by General formula (C): (MII.sub.1-pEu.sub.p)MIIISiN.sub.3, having a reflectance of light emission in a longer wavelength region of visible light than a peak wavelength of 95% or larger, and a method of producing such phosphor; a nitride phosphor and an oxynitride phosphor which emit light efficiently and stably by the light having a wavelength ranging from 430 to 480 nm from a semiconductor light emitting device by means of a light emitting apparatus using such phosphor, and a producing method of such phosphor; and a light emitting apparatus having stable characteristics and realizing high efficiency.