Complex Crystal Phosphor, Light Emitting Device, Surface Light Source Apparatus, Display Apparatus, and Lighting Device

• US 20110234118A1
• Filed: 03/24/2011
• Published: 09/29/2011
• Est. Priority Date: 03/26/2010
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung LED Co., Ltd. (Samsung Electronics Co. Ltd.)
• Inventors: Kim, Do Hwan, Kim, Sang Hyun, Yoon, Chul Soo, Ryu, Jeong Ho
• Granted Patent: US 8,821,758 B2
• Time in Patent Office: Days
• US Class Current: 315/291
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/77347 Silicon Nitrides or Silicon Oxynitrides
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: H01L 33/502 Wavelength conversion materials

Abstract

A complex crystal phosphor is an inorganic composition containing at least an M element, an Al element, silicon, oxygen, and nitrogen. The inorganic composition has particles having at least two types of crystal phase, and the at least two types of crystal phase include a first crystal phase which is the same as a M₂SiO₄ crystal and a second crystal phase as a β-sialon crystal. Here, M is at least one element selected from the group consisting of (Mg), calcium (Ca), strontium (Sr), and barium (Ba).

Claims

1. A complex crystal phosphor of an inorganic composition comprising an M element, an Al element, silicon, oxygen, and nitrogen,

wherein the inorganic composition has particles at least two types of crystal phase, and the two types of crystal phase include a first crystal phase of a M₂SiO_4-yN_x (0<

x<

3. y=2x/3) crystal and a second crystal phase of a β

-sialon crystal,

wherein M is at least one element selected from the group consisting of (Mg), calcium (Ca), strontium (Sr), and barium (Ba).

2. The phosphor of claim 1, wherein when an excitation source is irradiated, the complex crystal phosphor emits light having a peak wavelength ranging from about 570 nm to about 660 nm.

3. The phosphor of claim 2, wherein an emission wavelength spectrum of the complex crystal phosphor has a substantially single peak wavelength.

4. The phosphor of claim 2, wherein the excitation source has a peak wavelength ranging from about 300 nm to about 480 nm.

5. The phosphor of claim 3, wherein the half amplitude of the light emission wavelength spectrum is approximately 100 nm or greater.

6. The phosphor of claim 1, wherein the first crystal phase is Sr₂SiO_4-xN_y (0<

x<

3, y=2x/3).

7. The phosphor of claim 1, wherein the second crystal phase is Si_6-zAl_zO_zN_8-z (0<

z<

1).

8. The phosphor of claim 1, wherein the first crystal phase is contained at about 60 to about 95 mass percent, and the second crystal phase is contained at about 5 to about 40 mass percent.

9. The phosphor of claim 1, wherein the complex crystal phosphor comprises a quasi-orthorhombic crystal in which the two crystal phases are mutually employed.

10. The phosphor of claim 1, wherein the complex crystal phosphor further comprises a third crystal phase as a M₂Si₅O_aN_8-b (0<

a<

3, b=2a/3) crystal.

11. The phosphor of claim 1, wherein the first crystal phase is contained at about 50 to about 90 mass percent, the second crystal phase is contained at about 5 to about 40 mass percent, and the third crystal phase is contained at about 10 mass percent or less.

12. The phosphor of claim 1, wherein the phosphor further comprises at least one type of rare earth element as an activator.

13. The phosphor of claim 1, wherein the rare earth element (Re) is selected from the group consisting of cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), Holmium (Ho), erbium (Er), thulium (Tm), and ytterbium (Yb).

14. A white light emitting device comprising:

an LED chip emitting excitation light;

a red phosphor disposed around the LED chip to wavelength-convert at least a portion of the excitation light and including the complex crystal phosphor according to claim 1; and

at least one light emitting element providing light of a wavelength different from a light emission wavelength of the LED chip and a light emission wavelength of the red phosphor,

wherein the at least one light emitting element is at least one of an additional LED chip and a different type of phosphor.

15. The device of claim 13, wherein the LED chip is an LED chip emitting ultraviolet light.

16. The device of claim 13, wherein the LED chip is a blue LED chip having a peak wavelength ranging from about 430 nm to about 470 nm, and the at least one light emitting element comprises a green phosphor.

17. The device of claim 15, wherein the light emission wavelength peak of the red phosphor ranges from 600 nm to 660 nm, and the light emission wavelength peak of the green phosphor ranges from about 500 nm to about 550 nm.

18. The device of claim 16, wherein the blue LED chip has a half amplitude ranging from about 10 nm to about 50 nm, the green phosphor has a half amplitude ranging from about 30 nm to about 200 nm, and the red phosphor has a half amplitude ranging from about 100 nm to about 250 nm.

19. The device of claim 15, wherein the green phosphor comprises at least one of an oxynitride phosphor expressed by an empirical formula M_xA_yO_xN_(4/3)y, an oxynitride phosphor expressed by M_aA_bO_cN_{((2/3)a+(4/3)b−}

(2/3)c), and a β

-sialon phosphor expressed by Si_6-zAl_zO_zN_8-z.

wherein M is at least one type of a group II element selected from the group consisting of beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), and zinc (Zn), and A is at least one type of a group IV element selected from the group consisting of carbon (C), silicon (Si), germanium (Ge), tin (Sn), titanium (Ti), zirconium (Zr), and hafnium (Hf).

20. The device of claim 15, wherein the at least one light emitting element further comprises a yellow or yellowish-orange phosphor.

21. The device of claim 19, wherein the yellow phosphor is a silicate-based phosphor, and the yellowish-orange phosphor is a α

-SiAlON;

Re phosphor.

22. The device of claim 13, wherein the at least one light emitting element is a green LED chip.

23. The device of claim 13, wherein the LED chip has a structure in which first and second electrodes face the same surface.

24. The device of claim 13, wherein the LED chip has a structure in which the first and second electrodes face different opposing surfaces.

25. The device of claim 13, wherein the LED chip comprises:

a semiconductor stacked body having first and second conductive semiconductor layers providing first and second main surfaces opposed to each other and an active layer formed between the first and second conductive semiconductor layers, a contact hole connected to one area of the first conductive semiconductor layer from the second main surface through the active layer, a first electrode formed on the second main surface of the semiconductor stacked body and connected to one area of the first conductive semiconductor layer through the contact hole, and a second electrode formed on the second conductive semiconductor layer formed on the second main surface of the semiconductor stacked body.

26. The device of claim 24, wherein any one of the first and second electrodes is drawn out laterally from of the semiconductor stacked body.

27. The device of claim 13, further comprising a package main body having a recess in which the LED chip is mounted.

28. The device of claim 13, further comprising a resin packaging part encapsulating the LED chip, wherein at least one of the plurality of phosphors is dispersed in the resin packaging part.

29. The device of claim 13, wherein the plurality of phosphors form a plurality of different phosphor-contained resin layers, and the plurality of phosphor-contained resin layers may have a stacked structure.

30. The device of claim 14, wherein a color rendering index (CRI) of white light emitted from the white light emitting device is about 70 or higher.

31. A surface light source apparatus using the complex crystal phosphor according to claim 1 as a wavelength conversion material.

32. A surface light source apparatus comprising:

a light guide plate; and

an LED light source module disposed on at least one side of the light guide plate and providing light to the interior of the light guide plate,

wherein the LED light source module comprises a circuit board and a plurality of white light emitting devices mounted on the circuit board and using the complex crystal phosphor according to claim 1 as a wavelength conversion material.

33. A display apparatus using the complex crystal phosphor according to claim 1 as a wavelength conversion material.

34. A display apparatus comprising:

an image display panel displaying an image; and

a backlight unit having a surface light source apparatus according to claim 30 to provide light to the image display panel;

35. A lighting device using the complex crystal phosphor according to claim 1 as a wavelength conversion material.

36. A lighting device comprising:

an LED light source module; and

a diffusion sheet disposed at an upper side of the LED light source module and uniformly diffusing light made incident from the LED light source module,

wherein the LED light source module comprises a circuit board and a plurality of white light emitting devices mounted on the circuit board and using the complex crystal phosphor according to claim 1 as a wavelength conversion material.

37. A method for generating a light with an enhanced half amplitude of the light emission wavelength spectrum, comprising a) providing electricity to an light emitting device to generate an emission light and b) allowing the emission light pass through a phosphor having the complex crystal phosphor according to claim 1 to generate the light with an enhanced half amplitude of the light emission wavelength.