Nichia Corporation

Tomokazu Suzuki

Kazushige Fujio

Mika Amiya

Provided is a near-infrared light emitting fluorescent material including an oxide containing Gd, Cr and Al, in which a molar ratio of Cr is in a range of 0.0085 or more and 0.05 or less when a total molar ratio of Gd and Cr is defined as 1 in 1 mol of the chemical composition of the near-infrared light emitting fluorescent material, and having a light emission peak wavelength in a range of 690 nm or more and 790 nm or less, as excited with light having a light emission peak wavelength in a range of 380 nm or more and 480 nm or less.

Near-infrared light emitting fluorescent material

Provided are a light emitting device and an illumination device. The light emitting device is provided with a light emitting element having a light emission peak wavelength in a wavelength range of 380 nm or more and 490 nm or less, a first fluorescent material which is excited by the light from the light emitting element to emit light having at least one light emission peak wavelength in a wavelength range of 580 nm or more and less than 680, and a second fluorescent material which is excited by the light from the light emitting element to emit light having at least one light emission peak wavelength in a wavelength range of 680 nm or more and 800 nm or less, wherein a ratio R/B of a photon flux R of red light in a wavelength range of 620 nm or more and less than 700 nm to a photon flux B of blue light in a wavelength range of 400 nm or more and 490 nm or less is more than 4 and 50 or less, a ratio R/Fr of the photon flux R to a photon flux Fr of far-red light in a wavelength range of 700 nm or more and 780 nm or less is 0.1 or more and 10 or less, and the second fluorescent material contains at least one fluorescent material selected from the group consisting of a first aluminate fluorescent material and a second aluminate fluorescent material.

Light emitting device, illumination device and plant cultivation method

Provided is a light emitting device that includes a light emitting element having a light emission peak wavelength ranging from 380 nm to 490 nm, and a fluorescent material excited by light from the light emitting element and emitting light having at a light emission peak wavelength ranging from 580 nm or more to less than 680 nm. The light emitting device emits light having a ratio R/B of a photon flux density R to a photon flux density B ranging from 2.0 to 4.0 and a ratio R/FR of the photon flux density R to a photon flux density FR ranging from 0.7 to 13.0, the photon flux density R being in a wavelength range of 620 nm or more and less than 700 nm, the photon flux density B being in a wavelength range of 380 nm or more and 490 nm or less, and the photon flux density FR being in a wavelength range of 700 nm or more and 780 nm or less.

Light emitting device and plant cultivation method

Provided is a method for producing a fluorescent material, including: preparing a raw material mixture including a compound containing at least one rare earth element Ln selected from the group consisting of Y, Gd, La, Lu, Sc and Sm, a compound containing at least one Group 13 element selected from Al and Ga, a compound containing Tb, a compound containing Ce and a compound containing Eu, wherein the raw material mixture contains each compound such that each element satisfies a composition represented by the following formula (I): (LnTbCeEU)(AlGa)O(I), wherein a, b, c and d satisfy 0.25&#x2264;a&#x3c;1, 0.008&#xd7;10&#x2264;b&#x2264;1.5&#xd7;10, 0.012&#xd7;10&#x2264;c&#x2264;2&#xd7;10, and 0&#x2264;d&#x2264;0.85, and heat-treating the raw material mixture to obtain the fluorescent material.

Method for producing fluorescent material

Provided is a fluorescent material having a composition of rare earth aluminum-gallate, which radiates light in not only a visible light region but also a near-infrared region and has improved light emission intensity in a near-infrared region. The fluorescent material has a composition of rare earth aluminum-gallate, including at least one rare earth element Ln selected from the group consisting of Y, Gd, Sc, Lu, and La; at least one element selected from Al and Ga; Ce; and Nd. When a total molar composition ratio 5 of Al and Ga is used as a basis, a total molar ratio of Ln, Ce, and Nd is 3; a molar ratio of Ce is a product of 3 and a value of a parameter x; a molar ratio of Nd is a product of 3 and a value of a parameter y. The parameter x is in a range of 0.03 or more and 0.015 or less. The parameter y is in a range of 0.002 or more and 0.06 or less.

Fluorescent material having a composition of rare earth aluminum-gallate

Provided are a fluorescent material and a light emitting device using the fluorescent material. The fluorescent material has a composition represented by the following formula (I):(LnTbCeEu)(AlGa)O&#x2003;&#x2003;(I)

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Tokushima, Japan

Tomokazu Suzuki