Nerima-ku, Japan
Nerima-ku, Japan

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Patent
Tamura Corporation and Koha Co. | Date: 2017-05-10

Provided is a gallium oxide substrate which has less linear pits. Obtained is a gallium oxide substrate wherein the average density of linear pits in a single crystal surface is 1,000 pits/cm2 or less.


Patent
Tamura Corporation and Koha Co. | Date: 2017-05-03

A high-quality -Ga2O3 single-crystal substrate having little variation in crystal structure is provided. Provided in one embodiment is a -Ga203 single-crystal substrate 1 formed from a -Ga2O3 single crystal, wherein the principal surface is a plane parallel to the b axis of the -Ga203 single crystal and the maximum value of on any straight line on the principal surface which passes through the center of the principal surface is not more than 0.7264. is the difference between the maximum value and the minimum value obtained by subtracting a from s at each measurement position, where: s represents the angle formed by the incident direction of the X ray at the peak position of an X-ray rocking curve and the principal surface on the straight line; and a represents the angle on a straight approximation line obtained by using the method of least squares to linearly approximate the curve representing the relationship between the aforementioned s and the measurement position therefor.


Patent
Tamura Corporation and Koha Co. | Date: 2015-07-01

Provided is a gallium oxide substrate which has less linear pits. Obtained is a gallium oxide substrate wherein the average density of linear pits in a single crystal surface is 1,000 pits/cm2 or less.


Patent
Koha Co., Tamura Corporation and Japan National Institute of Materials Science | Date: 2016-06-15

Provided is a light emitting device which is suitable for a lighting apparatus, such as a projector, requiring high brightness and high light intensity exhibits little change in light emission colour and a low reduction in light emission intensity during usage, and uses a remote phosphor. According to one embodiment of the present invention, the light emitting device (10) has: an LED element (12); a side wall (13) which surrounds the LED element (12); a phosphor layer (15) which is fixed to the side wall (13) with an adhesive layer (14) therebetween, and is positioned above the LED element (12); and a metal pad (11) as a heat dissipating member. The side wall (13) has: an insulating base (13b) which surrounds the LED element (12); and a metal layer (13a) which is formed on a side surface at the LED element (12) side of the base (13b), and is in contact with the metal pad (11) and the adhesive layer (14). The adhesive layer (14) is: a resin layer that comprises a resin containing particles which have higher thermal conductivity than the resin; or a layer that comprises solder.


Patent
Koha Co. and Japan National Institute of Materials Science | Date: 2016-03-30

Provided are: a YAG-based single crystal phosphor which produces fluorescence of a non-conventional color; and a phosphor-containing member and a light emitting device, each of which is provided with this single crystal phosphor. Provided as one embodiment of the present invention is a single crystal phosphor which has a composition represented by composition formula (Y_(1-a-b)Lu_(a)Ce_(b))_(3+c)Al_(5-c)O_(12) (wherein 0 a 0.9994, 0.0002 b 0.0067 and -0.016 c 0.315), and which has an emission spectrum having CIE chromaticity coordinates x and y satisfying the relation -0.4377x + 0.7384 y -0.4585x + 0.7504 when the peak wavelength of the excitation light is 450 nm at the temperature of 25C.


Patent
Koha Co. and Japan National Institute of Materials Science | Date: 2015-03-04

One purpose of the invention is to provide a phosphor with excellent quantum efficiency, a method for manufacturing the same, and a light-emitting device that uses this phosphor. One embodiment provides a phosphor comprising monocrystals with YAG crystals as a matrix, the quantum efficiency of the phosphor at 25C being 92% or higher at an excitation light wavelength of 460 nm.


Provided are: a method for cultivating a -Ga_(2)O_(3) single crystal which makes it possible to obtain a flat -Ga_(2)O_(3) single crystal having high crystal quality; a -Ga_(2)O_(3)-single-crystal substrate; and a method for producing the same. Provided is one embodiment which is a method for cultivating a -Ga_(2)O_(3) single crystal (25) including a step for contacting a flat seed crystal (20) with a Ga_(2)O_(3) melt (12), and a step for pulling up the seed crystal (20) and growing a flat -Ga_(2)O_(3) single crystal (25) having a principal surface (26a) which intersects a surface (100), in a manner such that the crystal information of the vaporized material (23) of the Ga_(2)O_(3) melt (12) adhered to the principal surface of the seed crystal (20) is not passed on, wherein when growing the -Ga203 single crystal (25), the shoulder of the -Ga_(2)O_(3) single crystal (25); is only widened in the thickness direction (t).


Patent
Koha Co. and Japan National Institute of Materials Science | Date: 2016-08-31

As one of purposes, the present invention provides: a single-crystal phosphor which can exhibit excellent properties under high-temperature conditions; and a light-emitting device in which the phosphor is used. As one embodiment, a single-crystal phosphor is provided, which has a chemical composition represented by the compositional formula: (Y_(1-x-y-z)Lu_(x)Gd_(y)Ce_(z))_(3+a)Al_(5-a)O_(12) (0 x 0.9994, 0 y 0.0669, 0.0002 z 0.0067, -0.016 a 0.315).


Patent
Tamura Corporation and Koha Co. | Date: 2016-03-02

Provided is a method for growing a -Ga_(2)O_(3)-based single crystal, whereby it becomes possible to grow a -Ga_(2)O_(3)-based single crystal having a small variation in crystal structure and also having high quality in the direction of the b axis. In one embodiment, a method for growing a -Ga_(2)O_(3)-based single crystal is provided, which comprises a step of growing a flat-plate-shaped Sn-containing -Ga_(2)O_(3)-based single crystal in the direction of the b axis using a seed crystal.


Provided are: a method for cultivating a -Ga_(2)O_(3) single crystal which makes it possible to obtain a wide -Ga_(2)O_(3) seed crystal and is to be used in the cultivation of a flat -Ga_(2)O_(3) single crystal which minimizes widening of the shoulder in the width direction; a -Ga_(2)O_(3)-single-crystal substrate obtained by using the same; and a production method therefor. Provided is one embodiment which is a method for cultivating a -Ga_(2)O_(3) single crystal which uses the EFG method and includes: a step for raising a Ga_(2)O_(3) melt (12) inside a crucible (13) up to a die (14) opening (14b) via a die (14) slit (14a), and while the horizontal position of a seed crystal (20) is shifted in the width direction (W) from the width direction (W) center of the die (14), contacting the seed crystal (20) and the Ga_(2)O_(3) melt (12) in the opening (14b) of the die (14); and a step for pulling up the seed crystal (20) which contacted the Ga_(2)O_(3) melt (12), and growing the -Ga_(2)O_(3) single crystal (25).

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