Red phosphor, white light emitting apparatus, display apparatus, and lighting apparatus
There is provided a red phosphor that may include a nitride represented by a formula of (Sr 1-x-y Ba x Eu y ) 2 Si 5 N 8 , wherein 0<x<0.7, and 0<y<0.1. The red phosphor may emit light having a peak wavelength in a range of 600 nm to 630 nm when irradiated by an excitation source and the excitation source may be a blue light source having a dominant wavelength in a range of 420 nm to 470 nm.
1. A red phosphor, comprising a nitride represented by a formula:
(Sr 1-x-y Ba x Eu y ) 2 Si 5 N 8 , wherein, 0<x<0.7 and 0.018<y<0.04,
wherein a median particle size (D50) in a particle size distribution of the red phosphor is in a range of 10 μm to 25 μm, and
wherein, when a quartile deviation (Q.D.) related to a particle size is defined as (D75−D25)/(D75+D25), the particle size distribution of the red phosphor satisfies 0.18≤Q.D.≤0.32.
2. The red phosphor of claim 1 , wherein the red phosphor is configured to emit light having a peak wavelength in a range of 600 nm to 630 nm when irradiated by an excitation source, and
the excitation source is a blue light source having a dominant wavelength in a range of 420 nm to 470 nm.
3. The red phosphor claim 1 , wherein the red phosphor comprises oxygen as an impurity, and a content of oxygen is 1 wt % or less.
4. The red phosphor of claim 1 , wherein, in the formula, 0.19<x<0.6.
5. A display device, utilizing the red phosphor according to claim 1 to convert a wavelength of light.
6. A white light emitting apparatus, comprising:
a semiconductor light-emitting device configured to emit excited light;
a red phosphor disposed around the semiconductor light-emitting device and configured to convert a wavelength of at least some of the excited light, wherein the red phosphor comprising a nitride represented by a formula (Sr 1-x-y Ba x Eu y ) 2 Si 5 N 8 , wherein, 0<x<0.7 and 0.018<y<0.04, wherein a median particle size (D50) in a particle size distribution of the red phosphor is in a range of 10 μm to 25 μm, and when a quartile deviation (Q.D.) related to a particle size is defined as (D75−D25)/(D75+D25), the particle size distribution of the red phosphor satisfies 0.18<Q.D.<0.32; and
at least one light-emitting component configured to provide light having a different wavelength from the excited light emitted by the semiconductor light-emitting device and light emitted by the red phosphor,
wherein the at least one light-emitting component comprises at least one from among another semiconductor light-emitting device and another phosphor.
7. The white light emitting apparatus of claim 6 , wherein the semiconductor light-emitting device comprises a blue semiconductor light-emitting device having a main wavelength in a range of 420 nm to 470 nm.
8. The white light emitting apparatus of claim 7 , wherein the at least one light-emitting component comprises a green phosphor.
9. The white light emitting apparatus of claim 8 , wherein the green phosphor is configured to have a peak wavelength in a range of 500 nm to 550 nm.
10. The white light emitting apparatus of claim 8 , wherein the green phosphor comprises at least one from among an oxide-based phosphor represented by a formula of M 3 Al 5 O 12 , a β-sialon phosphor represented by a formula of Si 6-z Al z O z N 8-z , and a La 3 Si 6 N 11 :Ce phosphor, wherein M comprises at least one selected from the group consisting of Y, Lu, Gd, Ga, Re, Mg, Ca, Sr, Ba, Zn, Eu, and Ce.
11. The white light emitting apparatus of claim 7 , wherein the at least one light-emitting component comprises a yellow phosphor or a yellowish orange phosphor.
12. The white light emitting apparatus of claim 11 , wherein the yellow phosphor or the yellowish orange phosphor has a peak wavelength in the range of 550 nm to 600 am.
13. The white light emitting apparatus of claim 11 , wherein the yellow phosphor comprises at least one from among a silicate-based phosphor, a garnet-based phosphor, and a nitride-based phosphor, and the yellowish orange phosphor comprises a α-SiAlON:Re phosphor.
14. A display device, comprising:
an image display panel configured to display an image; and
a backlight unit configured to provide light to the image display panel and comprising a light emitting diode (LED) light-source module,
wherein the LED light-source module comprises a circuit board, and the white light emitting apparatus according to claim 6 .
15. A lighting apparatus, comprising:
a light emitting diode (LED); and
a spread sheet configured to uniformly spread light incident from the LED,
wherein the LED comprises a circuit board and a white light emitting apparatus according to claim 6 , mounted on the circuit board.
16. A backlight unit (BLU) of a display apparatus, the BLU comprising:
a light emitting diode (LED) configured to emit light; and
a fluorescent member configured to convert a wavelength of the light emitted from the LED and emit light having the converted wavelength, the fluorescent member comprising a red phosphor, which comprises a nitride represented by a formula (Sr 1-x-y Ba x Eu y ) 2 Si 5 N 8 , wherein, 0<x<0.7 and 0.018<y<0.04, wherein a median particle size (D50) in a particle size distribution of the red phosphor is in a range of 10 μm to 25 μm, and when a quartile deviation (Q.D.) related to a particle size is defined as (D75−D25)/(D75+D25), the particle size distribution of the red phosphor satisfies 0.18<Q.D.<0.32.
17. The BLU of claim 16 , wherein the LED is configured to emit blue light and the fluorescent member is configured to convert a wavelength of the blue light to a wavelength of red light.