Light-emitting device having optical resonance layer

• US 8,525,154 B2
• Filed: 11/09/2005
• Issued: 09/03/2013
• Est. Priority Date: 11/10/2004
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Kim, Yoon-Chang, Song, Young-Woo, Cho, Sang-Hwan, Ahn, Ji-Hoon, Lee, Joon-Gu, Lee, So-Young, Oh, Jong-Seok, Ha, Jae-Heung
• Primary Examiner(s): Gurley, Lynne
• Assistant Examiner(s): Webb, Vernon P
• Application Number:
  US11/269,575
• Publication Number:
  US 20060097264A1
• Time in Patent Office: 2,855 Days
• Field of Search: 313/504, 257/40, 257/E33.055, 257/E33.002
• US Class Current: 257/40
• CPC Class Codes: H01L 33/465 with a resonant cavity structure
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/10 OLED displays
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels

Abstract

Provided is a light-emitting device which has a simple structure and can be manufactured in a simple process, has increased light coupling efficiency and brightness, and can reduce adverse effects of optical resonance on a view angle and emission spectrum. The light-emitting device includes a substrate; a light-emitting diode formed on the substrate; and an optical resonance layer formed outside the light-emitting diode that induces resonance of light emitted from the light-emitting diode.

Claims

1. A light-emitting device comprising:

a substrate;

a light-emitting diode arranged on the substrate;

an interlayer arranged between the substrate and the light-emitting diode; and

an optical resonance layer consisting of a first layer and a second layer arranged between the light-emitting diode and the substrate,

wherein an uppermost surface of the first layer directly contacts the interlayer, a lowermost surface of the second layer directly contacts the substrate, and a lowermost surface of the first layer directly contacts an uppermost surface of the second layer, the optical resonance layer to induce resonance of light emitted from the light-emitting diode, and

wherein a refractive index of the second layer is higher than that of the first layer.

2. The light-emitting device of claim 1, wherein the second layer has a higher refractive index than the first layer by 0.2 or more.

3. The light-emitting device of claim 1, wherein the first layer has a refractive index in the range of 1 to 1.6.

4. The light-emitting device of claim 1, wherein the first layer comprises nano porous silica, siloxane, magnesium fluoride, calcium fluoride, Teflon, silica aero gel, or silicon oxide.

5. The light-emitting device of claim 1, wherein the second layer has a refractive index in the range of 1.6 to 2.3.

6. The light-emitting device of claim 1, wherein the second layer comprises silicon nitride, titanium oxide, hafnium dioxide, niobium oxide, tantalum oxide, antimony oxide, synthetic polymer, or benzocylobutene (BCB).

7. The light-emitting device of claim 1, wherein the interlayer is composed of a denser material than the first layer.

8. The light-emitting device of claim 1, wherein the interlayer has a refractive index in the range of 1.3 to 2.3.

9. The light-emitting device of claim 1, wherein the interlayer comprises Ormocer, silicon oxide, benzocylobutene (BCB), or silicon nitride.

10. The light-emitting device of claim 1, wherein:

the light-emitting diode comprises a pair of electrodes opposing each other and a light-emitting layer arranged between the electrodes,

one electrode of the pair of electrodes comprises a reflective layer that reflects light emitted from the light-emitting layer, and

the optical resonance layer opposes the reflective layer with the light-emitting layer arranged therebetween.

11. The light-emitting device of claim 10, satisfying equation 4:

t4=(nλ

)/ 2  

 

(4)

wherein

t4 is a distance from a reflection interface of the reflective layer to an interface between the first layer and the second layer;

n is a positive integer; and

λ

is a wavelength of light emitted from the light-emitting layer.

12. The light-emitting device of claim 11, wherein t4 is controlled by adjusting a thickness of at least one of the first layer and the interlayer.

13. The light-emitting device of claim 10, satisfying equation 5:

t5=(2n +1)λ

/ 4  

 

(5)

wherein

t5 is a distance from a reflection interface of the reflective layer to an outer surface of the second layer;

n is a positive integer; and

λ

, is a wavelength of light emitted from the light-emitting layer.

14. The light-emitting device of claim 13, wherein t5 is controlled by adjusting a thickness of the second layer.

15. The light-emitting device of claim 1, wherein the light-emitting diode is an organic light-emitting diode.