Provided is an oxide fluorescent material having a light emission peak in a wavelength range from red light to near-infrared light.

The oxide fluorescent material has a composition including: a first element M.sup.1 being at least one element selected from the group consisting of Li, Na, K, Rb, and Cs; a second element M.sup.2 being at least one element selected from the group consisting of Ca, Sr, Mg, Ba, and Zn; Ge; O (oxygen); and Cr, the composition optionally including: a third element M.sup.3 being at least one element selected from the group consisting of Si, Ti, Zr, Sn, Hf, and Pb; and a fourth element M.sup.4 being at least one element selected from the group consisting of Eu, Ce, Tb, Pr, Nd, Sm, Yb, Ho, Er, Tm, Ni, and Mn. When the molar ratio of Ge, or the total molar ratio of the third element M.sup.3 and Ge in the case of comprising the third element M.sup.3, in 1 mol of the composition of the oxide fluorescent material is 6, the molar ratio of the first element M.sup.1 is 1.5 or more and 2.5 or less, the molar ratio of the second element M.sup.2 is 0.7 or more and 1.3 or less, the molar ratio of the third element M.sup.3 is 0 or more and 0.4 or less, the molar ratio of O (oxygen) is 12.9 or more and 15.1 or less, and the molar ratio of Cr is 0.2 or less. The oxide fluorescent material has a light emission peak wavelength of 700 nm or more and 1,050 nm or less in a light emission spectrum of the oxide fluorescent material.

A light-emitting device includes: a light source that radiates primary light; and a first phosphor that absorbs the primary light and converts the primary light into first wavelength-converted light having a longer wavelength than the primary light, wherein the primary light is laser light, the first wavelength-converted light includes fluorescence based on electron energy transition of Cr.sup.3+, and a fluorescence spectrum of the first wavelength-converted light has a maximum fluorescence intensity value in region of a wavelength exceeding 710 nm.

The present invention relates to a phosphor, a method for preparing the phosphor, an optoelectronic component, and a method for producing the optoelectronic component. The phosphor has the following general formula: La.sub.3(1x)Ga.sub.1yGe.sub.5(1z)O.sub.16: 3xA.sup.3+, yCr.sup.3+, 5zB.sup.4+, where x, y, and z do not equal to 0 simultaneously; A represents at least one of Gd and Yb; B represents at least one of Sn, Nb, and Ta. For the phosphor, its emission spectrum is within a red visible light region and a near-infrared region when excited by blue visible light, purple visible light or ultraviolet light; and it has a wide reflection spectrum and a high radiant flux. Therefore, it can be used in optoelectronic components such as LEDs to meet requirements of current medical testing, food composition analysis, security cameras, iris/facial recognition, virtual reality, gaming notebook and light detection and ranging applications.

A light-emitting device includes a light-emitting element and a phosphor that absorbs at least a portion of light from the light-emitting element and emits light. The phosphor includes two or more types of phosphors each having a light emission peak wavelength in a different range. The two or more types of phosphors are selected from the group consisting of a first phosphor having a light emission peak wavelength within a first range of 700 nm to less than 800 nm, a second phosphor having a light emission peak wavelength within a second range of 800 nm to less than 1100 nm, and a third phosphor having a light emission peak wavelength within a third range of 1100 nm to less than 1500 nm.

Provided is a light source device including: at least one light emitting element of at least one type; at least one far-red phosphor that, when excited by output light from the light emitting element, emits light having a peak in a wavelength range of 680 nm or more to less than 780 nm; and at least one phosphor that, when excited by the output light from the light emitting element, emits light having a peak in a wavelength range different from the wavelength range of the light emitted from the far-red phosphor. The spectrum of light emitted from the light source device has characteristic A below. This light source device has sufficient emission intensity over the entire visible range, i.e., over a wavelength range of from 400 nm to 750 nm inclusive.

Characteristic A: The ratio of a minimum emission intensity to a maximum emission intensity in a wavelength range of from 400 nm to 750 nm inclusive is 20% or more.

A light-emitting device includes: a light source that radiates primary light; and a first phosphor that absorbs the primary light and converts the primary light into first wavelength-converted light having a longer wavelength than the primary light, the first wavelength-converted light includes fluorescence based on electron energy transition of Cr.sup.3+, and a fluorescence spectrum of the first wavelength-converted light has a maximum fluorescence intensity value in region of a wavelength exceeding 710 nm.

Provided is a phosphor represented by general formula (1) below,

(Gd.sub.1-x-y,Ln.sub.y,M.sup.II.sub.x).sub.3M.sup.III.sub.2(Ga.sub.1-z,M.sup.IV.sub.z).sub.3O.sub.12:Cr.sup.3+(1) where, in the formula, Ln is one or more elements selected from La, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Yb, and Lu, M.sup.II is a divalent element, M.sup.III is a trivalent element, M.sup.IV is a tetravalent element, and x, y, and z satisfy 0<x<0.5, 0?y<0.5, and 0<z<0.5.

Described herein are heterogeneous core@shell particles composed of a sensitizing persistent phosphor core and a lanthanide upconversion (UC) shell. The core@shell particles can be used for upconversion of visible light to ultraviolet light.

A light emitting device includes a light source that emits a primary light having a light energy density exceeding 0.5W/mm.sup.2, and a first phosphor that absorbs the primary light to convert the primary light into a first wavelength-converted light having a wavelength longer than that of the primary light. The first phosphor includes a compound serving as a host, the compound being a simple oxide including one kind of metal element or a composite oxide including a plurality of different kinds of the simple oxide as an end member. When an energy conversion value at a peak wavelength of the primary light is E1 electron volts and an energy conversion value at a fluorescence peak wavelength of the first wavelength-converted light is E2 electron volts, a bandgap energy of a crystal of the simple oxide is larger than a sum of the E1 electron volts and the E2 electron volts.

Provided is a light emitting device including a solid-state light-emitting element that emits primary light, a wavelength converter that includes a phosphor containing a fluorescent ion which absorbs the primary light on the basis of a forbidden transition-type electronic energy transition, and an optical member that reflects the primary light while transmitting fluorescence emitted by the fluorescent ion. The solid-state light-emitting element is arranged on a side of one surface of the wavelength converter and the optical member is arranged on a side of the other surface. The fluorescence emitted by the fluorescent ion passes through the optical member and is output to the outside of the light emitting device. An electronic apparatus includes the above-described light emitting device.