Light emitting device employing nanowire phosphors

• US 8,232,562 B2
• Filed: 08/02/2010
• Issued: 07/31/2012
• Est. Priority Date: 07/11/2005
• Status: Active Grant

• Current Assignee: Seoul Viosys Co., Ltd. (Seoul Semiconductor Co., Ltd.)
• Original Assignee: Seoul Optodevice Company Limited (Seoul Semiconductor Co., Ltd.)
• Inventors: Kim, Hwa-Mok
• Primary Examiner(s): Rizkallah, Kimberly
• Assistant Examiner(s): Laurenzi, Mark A
• Application Number:
  US12/848,632
• Publication Number:
  US 20100295441A1
• Time in Patent Office: 729 Days
• Field of Search: 362/555, 977/762, 257/81, 257/90, 257 97- 99, 257/E33.012, 257/E33.072, 438/22, 438/29, 438 34- 35, 438/428
• US Class Current: 257/79
• CPC Class Codes: C09K 11/54 containing zinc or cadmium
• CPC Class Codes: C09K 11/565 with zinc cadmium
• CPC Class Codes: C09K 11/574 with zinc or cadmium
• CPC Class Codes: C09K 11/584 with zinc or cadmium
• CPC Class Codes: C09K 11/595 with zinc or cadmium
• CPC Class Codes: C09K 11/623 with zinc or cadmium
• CPC Class Codes: C09K 11/642 with zinc or cadmium
• CPC Class Codes: C09K 11/883 with zinc or cadmium
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: Y10S 977/762 Nanowire or quantum wire, i.e. axially elongated structure having two dimensions of 100 nm or less

Abstract

Disclosed is a light emitting device employing nanowire phosphors. The light emitting device comprises a light emitting diode for emitting light having a first wavelength with a main peak in an ultraviolet, blue or green wavelength range; and nanowire phosphors for converting at least a portion of light having the first wavelength emitted from the light emitting diode into light with a second wavelength longer than the first wavelength. Accordingly, since the nanowire phosphors are employed, it is possible to reduce manufacturing costs of the light emitting device and to reduce light loss due to non-radiative recombination.

Claims

1. A light emitting device, comprising:

a light emitting diode to emit light having a first wavelength with a main peak in at least one wavelength range selected from ultraviolet, blue, and green wavelength ranges; and

a plurality of nanowire phosphors to convert at least a portion of light having the first wavelength emitted from the light emitting diode into light having a second wavelength longer than the first wavelength, the second wavelength having at least two main peaks in the range of visible light,

wherein each nanowire phosphor of the plurality of nanowire phosphors has a length greater than the diameter, wherein the diameter is less than 1 μ

m, and

wherein each nanowire phosphor of the plurality of nanowire phosphors is configured to convert the first wavelength of light into the second wavelength having at least two main peaks in the range of visible light.

2. The light emitting device of claim 1,

wherein the nanowire phosphors comprises Al_xIn_yGa_(1-x-y)N (0x≦

1, 0<

y<

1, 0<

x+y≦

1).

3. The light emitting device of claim 2,

wherein y=0.22 and the second wavelength is in the blue wavelength range.

4. The light emitting device of claim 1,

wherein the nanowire phosphors comprises a rod shape or a longitudinally curved wire shape.

5. The light emitting device of claim 1,

wherein the nanowire phosphors convert blue light into green light and yellow light.

6. The light emitting device of claim 1,

wherein the nanowire phosphors comprises nanowires made of ZnO doped with Ag, ZnO doped with at least one element selected from Al, Ga, In, and Li, or (Ba, Sr, Ca)₂SiO₄:

Eu.

7. The light emitting device of claim 2,

wherein y=0.33 and the second wavelength is in the green wavelength range.

8. The light emitting device of claim 2,

wherein y=0.40 and the second wavelength is in the yellow wavelength range.

9. The light emitting device of claim 2,

wherein y=0.55 and the second wavelength is in the red wavelength range.