Conversion LED with high color rendition index

• US 9,234,132 B2
• Filed: 08/11/2010
• Issued: 01/12/2016
• Est. Priority Date: 08/17/2009
• Status: Active Grant

• Current Assignee: OSRAM OLED GMBH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Baumann, Frank, Fiedler, Tim, Jermann, Frank, Lange, Stefan, Windisch, Reiner, Boenisch, Norbert
• Primary Examiner(s): Koslow, Carol M
• Application Number:
  US13/391,197
• Publication Number:
  US 20120146079A1
• Time in Patent Office: 1,980 Days
• Field of Search: 313/503, 257/98, 252/301.4 R, 252/301.4 F
• US Class Current: 1/1
• CPC Class Codes: C04B 2235/3224 Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
• CPC Class Codes: C04B 2235/3281 Copper oxides, cuprates or oxide-forming salts thereof, e.g. CuO or Cu2O
• CPC Class Codes: C04B 2235/3852 Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride
• CPC Class Codes: C04B 2235/444 Halide containing anions, e.g. bromide, iodate, chlorite
• CPC Class Codes: C04B 2235/445 Fluoride containing anions, e.g. fluosilicate
• CPC Class Codes: C04B 2235/446 Sulfides, tellurides or selenides
• CPC Class Codes: C04B 35/581 based on aluminium nitride
• CPC Class Codes: C04B 35/584 based on silicon nitride
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/7728 containing europium
• CPC Class Codes: C09K 11/7774 Aluminates
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials

Abstract

A conversion LED comprising a chip which emits primary radiation and a luminescent substance-containing layer which is on the chip or positioned so that it intercepts the primary radiation emitted from the chip and which converts at least some of the primary radiation of the chip into secondary radiation, wherein a first luminescent substance of the A₃B₅O₁₂:Ce garnet type which emits yellow green and a second luminescent substance of the MAlSiN₃:Eu calsine type which emits orange red is used, wherein the peak wavelength of the primary radiation lies in the 435 to 455 nm range, the first luminescent substance being a garnet having essentially the cation A=75 to 100% Lu, remainder Y and a Ce content of 1.5 to 2.9%, where B=10 to 40% Ga, remainder Al, while the second luminescent substance is of the basic MAlSiN₃:Eu type where M is Ca alone or at least 80%, in particular at least 90%, preferably at least 95% Ca and the remainder of M may be Sr, Ba, Mg, Li or Cu, in each case alone or in combination, wherein some of the Al up to 20%, preferably at most 5%, can be replaced by B, and wherein N can be partially replaced by O, F, Cl, alone or in combination.

Claims

1. A conversion LED comprising a chip which emits primary radiation and a luminescent substance-containing layer which is on the chip or positioned so that it intercepts the primary radiation emitted from the chip and which converts at least some of the primary radiation of the chip into secondary radiation, wherein a first luminescent substance of the A₃B₅O₁₂:

Ce garnet type which emits yellow green and a second luminescent substance of the MAlSiN₃;

Eu calsine type which emits orange red is used, wherein the peak wavelength of the primary radiation lies in the 435 to 455 nm range, the first luminescent substance being a garnet having essentially the cation A=75 to 100 mol. % Lu, remainder Y and a Ce content of 1.5 to 2.9 mol. %, where B=10 to 40 mol. % Ga, remainder Al, while the second luminescent substance is of the basic MAlSiN₃;

Eu type, where M is Ca alone or at least 80% Ca and the remainder of M is Sr, Ba, Mg, Li or Cu, in each case alone or in combination, wherein some and at most 5% of the Al is replaced by B, and wherein a part of N is optionally replaced by O, F, Cl, alone or in combination.

2. The conversion LED as claimed in claim 1, wherein the second luminescent substance contains Ca alone as component M.

3. The conversion LED as claimed in claim 1, wherein the second luminescent substance contains 0.2 to 1.3 mol.-% Eu as doping which is attributed to the component M.

4. The conversion LED as claimed in claim 1, wherein the first luminescent substance is A₃B₅O₁₂, where A=80 to 100% Lu, remainder Y and a Ce content of 1.5 to 2.5%, where B=15 to 25% Ga, remainder Al.

5. The conversion LED as claimed in claim 1, wherein said M contains at least 95% Ca.

6. The conversion LED as claimed in claim 1, wherein in the case of the component B the first luminescent substance contains 20 to 30 mol.-% Ga, the remainder being Al.

7. The conversion LED as claimed in claim 1, wherein the first luminescent substance contains 1.8% to 2.6 mol.-% Ce as doping which is attributed to the component A, the remainder being A.

8. The conversion LED as claimed in claim 1, wherein the second luminescent substance contains 0.3 to 0.9 mol.-% Eu as doping which is attributed to the component M.

9. The conversion LED as claimed in claim 1, which emits a mixed radiation of the primary radiation and the secondary radiation, said mixed radiation having a CRI between 96 to 98 with, at the same time, good red rendering with R9=90 to 99.

10. The conversion LED as claimed in claim 1, wherein in the second luminescent substance N is partially replaced by O, F, Cl, alone or in combination.