Phosphor, method for producing same, light emitting device, and image display device

Patent metadata

Field	Value
Publication number	US-9534171-B2
Application number	US-201314410822-A
Country	US
Kind code	B2
Filing date	Jun 26, 2013
Priority date	Jun 27, 2012
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

To provide a phosphor being chemically-thermally stable and having high luminous intensity if combined with LED of not exceeding 470 nm. A phosphor of the present invention includes: inorganic compound including: a crystal represented by Li 1 Ba 2 Al 1 Si 7 N 12 ; a crystal represented by (Li, A) 3 (D, E) 8 X 12 ; and an inorganic crystal having the same crystal structure as the crystal represented by Li 1 Ba 2 Al 1 Si 7 N 12 ; and a solid-solution crystal thereof, which contains Li, A, D, E, and X elements (A represents at least one selected from Mg, Ca, Sr, Ba, Sc, Y and La; D represents at least one selected from Si, Ge, Sn, Ti, Zr and Hf; E represents at least one selected from B, Al, Ga and In; and X represents at least one selected from O, N and F), wherein M element (M represents at least one selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy and Yb) is solid-solved into each.

First claim

What is claimed is:

1. A phosphor comprising:
an inorganic compound comprising:
a crystal represented by LiBa 2 AlSi 7 N 12 ,
an inorganic crystal having a same crystal structure as a crystal structure of a crystal represented by LiBa 2 AlSi 7 N 12 , or
a solid solution crystal of these crystals, which comprises at least a Li element, an A element, a D element, an E element, and an X element (here, A is at least one kind of element selected from a group consisting of Mg, Ca, Sr, Ba, Sc, Y, and La; D is at least one kind of element selected from a group consisting of Si, Ge, Sn, Ti, Zr, and Hf; E is at least one kind of element selected from a group consisting of B, Al, Ga, and In; X is at least one kind of element selected from a group consisting of O, N, and F), into which an M element is solid-solved (here, M is at least one kind of element selected from a group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb)

wherein the inorganic crystal is represented by (Li, A) 3 (D, E) 8 X 12 wherein both Li and A are present and both D and E are present, respectively.

2. The phosphor according to claim 1 , wherein the inorganic crystal having the same crystal structure as the crystal structure of the crystal represented by LiBa 2 AlSi 7 N 12 comprises: at least Ba as the A element, Si as the D element, Al as the E element and N as the X element, and O as the X element if necessary.

3. The phosphor according to claim 1 , wherein the inorganic crystal having the same crystal structure as the crystal structure of the crystal represented by LiBa 2 AlSi 7 N 12 is Li(Ba, La) 2 (Al, Si) 8 (O, N) 12 , Li (Ba, Sr) 2 (Al, Si) 8 (O, N) 12 , or LiBa 2 (Al, Si) 8 (O, N) 12 wherein both Ba and La are present, both Al and Si are present, both O and N are present, and both Ba and Sr are present in respective parentheses.

4. The phosphor according to claim 1 , wherein the inorganic crystal having the same crystal structure as the crystal structure of the crystal represented by LiBa 2 AlSi 7 N 12 is represented by a composition formula of LiBa 2 Si 7−x Al 1+x O x N 12−x , Li(Ba, La) 2 Si 7−x Al 1+x O x N 12−x , or Li(Ba, Sr) 2 Si 7−x Al 1+x O x N 12−x (where 0≦x≦4) wherein both Ba and La are present and both Ba and Sr are present in respective parentheses.

5. The phosphor according to claim 1 , wherein the M element is Eu.

6. The phosphor according to claim 1 , wherein the inorganic crystal having the same crystal structure as the crystal structure of the crystal represented by LiBa 2 AlSi 7 N 12 is a crystal in an orthorhombic system.

7. The phosphor according to claim 1 , wherein the inorganic crystal having the same crystal structure as the crystal structure of the crystal represented by LiBa 2 AlSi 7 N 12 is a crystal in an orthorhombic system and has a symmetry in a space group Pnnm, and lattice constants a, b, and c have values in ranges:
a =1.40941±0.05 nm;
b =0.48924±0.05 nm; and
c =0.80645±0.05 nm.

8. The phosphor according to claim 1 ,
wherein the inorganic compound is represented by a composition formula of Li z M d A e D f E g X h (where z+d+e+f+g+h=1 in the formula; M is at least one kind of element selected from a group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb; A is at least one kind of element selected from a group consisting of Mg, Ca, Sr, Ba, Sc, Y, and La; D is at least one kind of element selected from a group consisting of Si, Ge, Sn, Ti, Zr, and Hf; E is at least one kind of element selected from a group consisting of B, Al, Ga, and In; and X is at least one kind of element selected from a group consisting of O, N, and F) and
wherein the parameters z, d, e, f, g, and h satisfy all conditions:
0.035≦z≦0.05;

0.00001≦d≦0.05;

0.05≦e≦0.1;

0.2≦f≦0.4;

0.03≦g≦0.1; and

0.45≦h≦0.6.

9. The phosphor according to claim 8 , wherein values of the parameters z, d, e, f, g, and h are within a range satisfying all conditions of:
z+d+e =(3/23)±0.05;

f+g =(8/23)±0.05; and

h =(12/23)±0.05.

10. The phosphor according to claim 8 , wherein values of the parameters f and g satisfy a condition of:
5/8 <f /( f+g )<1.

11. The phosphor according to claim 8 , wherein:
the X element includes N and O,
the inorganic compound is represented by a composition formula of Li z M d A e D f E g O h1 N h2 (where z+d+e+f+g+h1+h2=1, and h1+h2=h in the formula), and
a condition of: 0<h1/(h1+h2)≦4/12 is satisfied.

12. The phosphor according to claim 8 , wherein the M element includes at least Eu.

13. The phosphor according to claim 8 , wherein:
the A element at least includes Ba;
the D element includes Si;
the E element includes Al; and
the X element includes N, and
the X element includes O if necessary.

14. The phosphor according to claim 1 , wherein the inorganic compound is represented by a composition formula, with parameters x and y, of:
Eu y LiBa 2−y Si 7−x Al 1+x N 12−x O x ,
Eu y Li(Ba, La) 2−y Si 7−x Al 1+x N 12−x O x wherein both Ba and La are present, or
Eu y Li(Ba, Sr) 2−y Si 7−x Al 1+x N 12−x O x wherein both Ba and Sr are present,
wherein 0≦x≦4, and 0.0001≦y <2.

15. The phosphor according to claim 1 , wherein the phosphor emits fluorescent having a peak in a wavelength range from 500 nm to 550 nm upon irradiation of an excitation source.

16. The phosphor according to claim 15 , wherein the excitation source is an electron beam; an X-ray or light having a wavelength that is at least 100 nm and not exceeding 450 nm, the light being a vacuum ultraviolet ray, an ultraviolet ray or visible light.

17. The phosphor according to claim 1 , wherein:
Eu is solid-solved into the crystal represented by LiBa 2 AlSi 7 N 12 or the inorganic crystal having a same crystal structure as the crystal structure of the crystal represented by LiBa 2 AlSi 7 N 12 ; and
the phosphor emits fluorescent of green color having an emission peak in a wavelength range of at least 500 nm and not exceeding 550 nm upon irradiation of light having a wavelength from 360 nm to 450 nm.

18. The phosphor according to claim 1 , wherein a color of light emitted upon irradiation of an excitation source satisfies conditions:
0≦x0≦0.5; and

0.1≦y0≦0.9

in terms of values of (x0, y0) of CIE 1931 chromaticity coordinates.

19. A method of manufacturing a phosphor recited in claim 1 comprising:
firing a raw material mixture of metal compounds in an inert atmosphere including nitrogen in a temperature range of at least 1,200° C. and not exceeding 2,200° C. wherein the raw material mixture could constitute an inorganic compound by firing the mixture,
wherein the inorganic compound comprises:
a crystal represented by LiBa 2 AlSi 7 N 12 ,
an inorganic crystal having a same crystal structure as a crystal structure of a crystal represented by LiBa 2 AlSi 7 N 12 , or
a solid solution crystal of these crystals, which comprises at least a Li element, an A element, a D element, an E element, and an X element (here, A is at least one kind of element selected from a group consisting of Mg, Ca, Sr, Ba, Sc, Y, and La; D is at least one kind of element selected from a group consisting of Si, Ge, Sn, Ti, Zr, and Hf; E is at least one kind of element selected from a group consisting of B, Al, Ga, and In; X is at least one kind of element selected from a group consisting of O, N, and F), into which an M element is solid-solved (here, M is at least one kind of element selected from a group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb)

wherein the inorganic crystal is represented by (Li, A) 3 (D, E)

Assignees

• Nat Inst For Materials Science

Inventors

• Hirosaki Naoto
• Takeda Takashi
• Funahashi Shiro
• Narimatsu Eiichirou

Classifications

• H10W90/756

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W72/5522

  comprising gold [Au] · CPC title

• H10W72/01515

  Forming coatings · CPC title

• H10W72/075

  of bond wires · CPC title