公开(公告)号：US20210095204A1

公开(公告)日：2021-04-01

申请号：US17033881

申请日：2020-09-27

Applicant: NICHIA CORPORATION

Inventor： Hiroshi Ogasa ,  Masato Okawa ,  Atsushi Yoshinari ,  Kazuya Nishimata

IPC: C09K11/77 ,  H01L33/50

Abstract: A method for producing a rare earth aluminate fluorescent material includes: subjecting a compound containing Ln that is at least one rare earth element to a first heat treatment at a temperature in a range of 1,000° C. or more and 1,600° C. or less; preparing a raw material containing an oxide containing Ln having a crystallite diameter of 1,500 Å or more obtained through the first heat treatment, a compound containing Ce, a compound containing Al, and optionally a compound containing Ga, having a chemical composition having a total molar ratio of Ln and Ce of 3, a total molar ratio of Al and Ga of a product of 5 and a parameter k of 0.95 or more and 1.05 or less, a molar ratio of Ce of a product of 3 and a parameter n of 0.005 or more and 0.050 or less, and a molar ratio of Ga of a product of a parameter m of 0 or more and 0.6 or less, the parameter k, and 5, and providing a mixture containing the raw material and a compound containing an alkaline earth metal element as a flux in an amount of 2.5% by mass or more and 7.5% by mass or less based on a total amount of the raw material; and subjecting the mixture to a second heat treatment at a temperature in a range of 1,400° C. or more and 1,800° C. or less to provide a calcined product.

公开(公告)号：US11677050B2

公开(公告)日：2023-06-13

申请号：US17303376

申请日：2021-05-27

Applicant: NICHIA CORPORATION

Inventor： Makiko Iwasa ,  Kazuya Nishimata ,  Atsushi Yoshinari ,  Shoji Hosokawa ,  Masato Okawa ,  Yasuaki Mashima

IPC: H01L33/50 ,  F21K9/64 ,  C09K11/77 ,  F21Y115/10 ,  H01L33/62 ,  H01L51/50

CPC classification number: H01L33/504 ,  C09K11/77212 ,  C09K11/77348 ,  F21K9/64 ,  F21Y2115/10 ,  H01L33/62 ,  H01L51/502

Abstract: A light emitting device includes a light emitting element having a dominant wavelength in a range of 400 nm or more and 500 nm or less, and a wavelength conversion member that is arranged on a light emitting side of the light emitting element and includes a rare earth aluminate fluorescent material having a composition represented by the following formula (I), wherein the light emitting device emits light having a dominant wavelength in a range of 475 nm or more and 500 nm or less, and wherein the light emitting device emits light having an S/P ratio of 6.5 or less derived from the formula (1), which is the ratio of a luminous flux in scotopic vision relative to a luminous flux in photopic vision:

(Lu1-p-nLnpCen)3(Al1-mGam)5kO12  (I)



wherein in the formula (I), Ln represents at least one rare earth element selected from the group consisting of Y, La, Gd, and Tb, and the parameters k, m, n, and p satisfy 0.95≤k≤1.05, 0.05≤m≤0.70, 0.002≤n≤0.050, and 0≤p≤0.30, respectively.