Phosphor, manufacturing method thereof, and light-emitting device using the phosphor

1. A red-light emitting phosphor particle, comprising potassium fluorosilicate and having a composition represented by the formula (A) at a surface thereof:

K a SiF b   (A),

where 1.5≤a≤2.5 and 5.5≤b≤6.5,

wherein the red-light emitting phosphor particle is activated by manganese,

the composition as a whole is represented by the formula (B):

K c (Si 1-x ,Mn x )F d   (B),

where 1.5≤c≤2.5, 5.5≤d≤6.5 and 0<x≤0.06

a total of an amount of manganese present on a superficial face of the red-light emitting phosphor particle and an area under the superficial face reachable by the X-ray photoelectron spectroscopy with the following conditions is not more than 0.2 mol % based on the total amount of all elements on the surface:

X-ray source: AlKα line,

power: 40 W,

measuring area: Φ 200 μm,

pass energy:

wide scan: 187.85 eV (1.60 eV/step)

narrow scan: 58.70 eV (0.125 ev/step),

charge neutralization gun: e − in use with Art, and

takeoff angle: 45°,

the amounts of oxygen and fluorine in the red-light emitting phosphor particle satisfy [oxygen content]/[(fluorine content)+(oxygen content)]<0.05, and

the red-light emitting phosphor particle has an internal quantum efficiency η′ of 60% or more, where the internal quantum efficiency if is calculated by the formula (II):

internal

⁢

⁢

quantum

⁢

⁢

efficiency

⁡

(

η

′

)

=

(

∫

λ

·

[

P

⁡

(

λ

)

]

⁢

d

⁢

⁢

λ

)

(

∫

λ

·

[

E

⁡

(

λ

)

-

R

⁡

(

λ

)

]

⁢

d

⁢

⁢

λ

)

(

II

)

wherein

E(λ) is the whole spectrum of light emitted by an excitation light source onto the red-light emitting phosphor particle in terms of number of photons,

R(λ) is the spectrum of light emitted by the excitation light source and reflected by the red-light emitting phosphor particle in terms of the number of photons, and

P(λ) is the emission spectrum of the red-light emitting phosphor particle in terms of the number of photons.

2. The red-light emitting phosphor particle according to claim 1 , having a light absorptivity of 10% or less in the wavelength range of from 600 nm to 650 nm.

3. A method for manufacturing the red-light emitting phosphor particle according to claim 2 , comprising:

immersing a silicon source in a reaction solution comprising potassium permanganate and hydrogen fluoride such that the silicon source is reacted with the reaction solution and that a crystal is formed;

separating the crystal from the reaction solution;

washing the crystal with a weak acid after the separating; and

subjecting the crystal to rinse treatment after the washing.

4. A light-emitting device, comprising:

a light-emitting element radiating light in the wavelength range of from 440 nm to 470 nm; and

a phosphor layer comprising the red-light emitting phosphor particle according to claim 2 .

5. The light-emitting device according to claim 4 , wherein the phosphor layer further comprises an orange- or red-light emitting phosphor particle.

6. A method for manufacturing the red-light emitting phosphor particle according to claim 1 , comprising:

immersing a silicon source in a reaction solution comprising potassium permanganate and hydrogen fluoride such that the silicon source is reacted with the reaction solution and that a crystal is formed;

separating the crystal from the reaction solution;

washing the crystal with a weak acid after the separating; and

subjecting the crystal to rinse treatment after the washing,

wherein the reaction solution comprises potassium permanganate and hydrogen fluoride in a molar ratio of from 1/200 to 1/40.

7. The method according to claim 6 , wherein, in the immersing, the silicon source is immersed in the reaction solution for 20 minutes to 80 minutes.

8. The method according to claim 6 , wherein the weak acid is at least one selected from the group consisting of hydrofluoric acid, acetic acid, carbonic acid and phosphoric acid.

9. The method according to claim 6 , wherein the silicon source is at least one selected from the group consisting of single crystal silicon, polycrystal silicon, amorphous silicon, crystalline silicon dioxide and amorphous silicon dioxide.

10. The method according to claim 6 , wherein the silicon source is a silicon substrate.

11. The method according to claim 6 , wherein the reaction solution comprises potassium permanganate in an amount of 1 wt % or more.

12. A light-emitting device, comprising:

a light-emitting element radiating light in the wavelength range of from 440 nm to 470 nm; and

a phosphor layer comprising the red-light emitting phosphor particle according to claim 1 .

13. The light-emitting device according to claim 12 , wherein the phosphor layer further comprises a green-light emitting phosphor particle having a main emission peak in the wavelength range of from 520 nm to 570 nm.

14. The light-emitting device according to claim 12 , wherein the phosphor layer further comprises a green- or yellow-light emitting phosphor particle.

15. The light-emitting device according to claim 14 , wherein the green- or yellow-light emitting phosphor particle is at least one selected from the group consisting of (Sr,Ca,Ba) 2 SiO 4 :Eu, Ca 3 (Sc,Mg) 2 Si 3 O 12 :Ce, (Y,Gd) 3 (Al,Ga) 5 O 12 :Ce, (Ca,Sr,Ba)Ga 2 S 4 :Eu, (Ca,Sr,Ba)Si 2 O 2 N 2 :Eu and (Ca,Sr)-αSiAlON.

16. The light-emitting device according to claim 12 , wherein the phosphor layer further comprises an orange- or red-light emitting phosphor particle.

17. The light-emitting device according to claim 16 , wherein the orange- or red-light emitting phosphor particle is at least one selected from the group consisting of (Sr,Ca,Ba) 2 SiO 4 :Eu, Li(Eu,Sm)W 2 O 8 , (La,Gd,Y) 2 O 2 S:Eu, (Ca,Sr,Ba)S:Eu, (Sr,Ba,Ca) 2 Si 5 N 8 :Eu, and (Sr,Ca)AlSiN 3 :Eu.