Semiconductor light-emitting device, semiconductor light-emitting system and illumination fixture

• US 8,779,455 B2
• Filed: 11/09/2012
• Issued: 07/15/2014
• Est. Priority Date: 06/02/2011
• Status: Active Grant

• Current Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Original Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Inventors: Kohara, Yuki, Satou, Yoshihito, Sakuta, Hiroaki
• Primary Examiner(s): KIM, SU C
• Application Number:
  US13/673,568
• Publication Number:
  US 20130082289A1
• Time in Patent Office: 613 Days
• Field of Search: 257/88, 257/89, 257/98, 257/99, 257/100, 257/103, 313501-503, 252/33.061, 252/301.4 F, 252/301.4 H, 438/22, 438/35, 438/38, 438/FOR.157, 438/FOR.293
• US Class Current: 257/98
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: C09K 11/7739 with halogens
• CPC Class Codes: F21W 2121/00 Use or application of lighting devices or systems for decorative purposes, not provided for in codes F21W2102/00 – F21W2107/00
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials

Abstract

The present invention provides a semiconductor light-emitting device that emits light with a specific low correlated color temperature and with a high Ra, and a semiconductor light-emitting system provided with the semiconductor light-emitting device. This object is attained by the semiconductor light-emitting device having the below-described configuration.

A semiconductor light-emitting device includes a LED chip as a semiconductor light-emitting element, and a phosphor emitting light using the LED chip as an excitation source, and emits light with a correlated color temperature equal to or higher than 1600 K and lower than 2400 K. The phosphor includes at least a green phosphor and a red phosphor. In the spectrum of light emitted from the semiconductor light-emitting device, the value of the peak intensity of the light emitted by the LED chip is less than 60% of the maximum peak intensity of the light emitted by the phosphor.

Claims

1. A semiconductor light-emitting device comprising:

a semiconductor light-emitting element radiating light having an emission peak equal to or higher than 380 nm and equal to or lower than 430 nm; and

a phosphor that emits light using the semiconductor light-emitting element as an excitation source,

the semiconductor light-emitting device emitting light with a correlated color temperature equal to or higher than 1600 K and lower than 2400 K, wherein

the phosphor includes at least a blue phosphor, a green phosphor, and a red phosphor, and

in a spectrum of light emitted from the semiconductor light-emitting device, a value of a peak intensity of the light emitted by the semiconductor light-emitting element is less than 60% of the maximum peak intensity of the light emitted by the phosphor, and the maximum peak of the light emitted by the phosphor is at a position equal to or greater than 600 nm and equal to or less than 660 nm.

2. The semiconductor light-emitting device according to claim 1, which emits light with a spectrum such that the value of the peak intensity of the light emitted by the light-emitting element is equal to or greater than 5% of the maximum peak intensity of the light emitted by the phosphor.

3. The semiconductor light-emitting device according to claim 1 or 2, which emits light with the correlated color temperature equal to or higher than 1600 K and lower than 2000 K.

4. The semiconductor light-emitting device according to any one of claim 1 or 2, wherein

the blue phosphor has a half-width of emission peak wavelength of equal to or greater than 30 nm.

5. The semiconductor light-emitting device according to any one of claim 1 or 2, wherein

the blue phosphor is (Sr,Ba,Ca)₅(PO₄)₃Cl:

Eu, or BaMgAl₁₀O₁₇;

Eu.

6. The semiconductor light-emitting device according to any one of claim 1 or 2, wherein

a chromaticity coordinate of the light emitted by the semiconductor light-emitting device has a value of a deviation duv from a black body radiation trajectory curve of equal to or greater than −

0.02 and equal to or less than 0.02 in a XY chromaticity diagram of a CIE (1931) XYZ color system.

7. The semiconductor light-emitting device according to any one of claim 1 or 2, wherein

the green phosphor is β

-Sialon, (Ba,Sr)₃Si₆O₁₂N₂;

Eu, or (Sr,Ba)₂SiO₄;

Eu.

8. The semiconductor light-emitting device according to any one of claim 1 or 2, wherein

the red phosphor includes (CaAlSiN₃)₁₋

x(Si₂N₂O)_x;

Eu (x satisfies the condition 0<

x<

0.5).

9. The semiconductor light-emitting device according to any one of claim 1 or 2, wherein

the red phosphor includes K₂SiF₆:

Mn.

10. The semiconductor light-emitting device according to any one of claim 1 or 2, wherein

the red phosphor includes A_2+xM_yMn_zF_n (where A is either or both of Na and K, M is Si and Al, and the following conditions are satisfied:

−

1≦

x≦

1;

0.9≦

y+z≦

1.1, 0.001≦

z≦

0.4, and 5≦

n≦

7).

11. The semiconductor light-emitting device according to any one of claim 1 or 2, wherein

the phosphor transmits the light emitted by the semiconductor light-emitting element with a predetermined transmittance and radiates the transmitted light to the outside of the light-emitting device.

12. The semiconductor light-emitting device according to any one of claim 1 or 2, further comprising a holding member that holds the phosphor, wherein

the holding member is configured such that the phosphor of each color is held in a predetermined region that is set for each color, and a phosphor layer is formed in which the regions where the phosphors are held for the respective colors are arranged, and

the phosphor layer is supported at a distance equal to or greater than 0.1 mm and equal to or less than 500 mm from the semiconductor light-emitting element.

13. A semiconductor light-emitting system comprising:

the semiconductor light-emitting device according to any one of claim 1 or 2 as a first semiconductor light-emitting device; and

a semiconductor light-emitting device that emits light with a correlated color temperature different from that of the light emitted by the first semiconductor light-emitting device, as a second semiconductor light-emitting device.

14. The semiconductor light-emitting system according to claim 13, wherein

a value of a general color rendering index Ra of the first semiconductor light-emitting device is equal to or greater than 86, and a value of a general color rendering index Ra of the second semiconductor light-emitting device is equal to or greater than 86.

15. An illumination fixture, comprising the semiconductor light-emitting device according to any one of claim 1 or 2.