Organic light emitting device and method of manufacturing the same

1. An organic light emitting device, comprising:

a pixel layer including i) first and second electrodes and ii) a light emitting portion located between the electrodes;

a transparent member through which light is transmitted;

a diffraction grating disposed between the pixel layer and the transparent member; and

a low-refractive layer having a refractive index less than that of the transparent member, the low-refractive layer disposed between the diffraction grating and the transparent member.

2. The organic light emitting device of claim 1 , wherein the transparent member, the low-refractive layer, the diffraction grating, the first electrode, the light emitting portion and the second electrode are sequentially stacked in that order, and wherein the transparent member is a substrate and the first electrode is a transparent electrode.

3. The organic light emitting device of claim 1 , wherein the first electrode, the light emitting portion, the second electrode, the diffraction grating, the low-refractive layer and the transparent member are sequentially stacked in that order, and wherein the second electrode is a transparent electrode and the transparent member is a protective layer or a seal member.

4. An organic light emitting device, comprising:

a pixel layer including i) first and second electrodes and ii) a light emitting portion located between the electrodes;

a transparent member through which light is transmitted;

a diffraction grating disposed between the pixel layer and the transparent member;

a low-refractive layer having a refractive index less than that of the transparent member, the low-refractive layer disposed between the diffraction grating and the transparent member; and

a light-absorbing layer disposed between the low-refractive layer and the transparent member.

5. The organic light emitting device of claim 4 , wherein the transparent member, the light-absorbing layer, the low-refractive layer, the diffraction grating, the first electrode, the light emitting portion and the second electrode are sequentially stacked in that order, and wherein the transparent member is a substrate and the first electrode is a transparent electrode.

6. The organic light emitting device of claim 4 , wherein the first electrode, the light emitting portion, the second electrode, the diffraction grating, the low-refractive layer, the light-absorbing layer and the transparent member are sequentially stacked in that order, and wherein the second electrode is a transparent electrode and the transparent member is a protective layer or a seal member.

7. The organic light emitting device of claim 1 , wherein the transparent member is formed of glass or a plastic material.

8. The organic light emitting device of claim 1 , wherein the low-refractive layer has a refractive index in the range of about 1 to about 1.5.

9. The organic light emitting device of claim 1 , wherein the low-refractive layer is formed of porous SiO 2 .

10. The organic light emitting device of claim 1 , wherein the low-refractive layer has a thickness in the range of about 100 nm to about 1000 nm.

11. The organic light emitting device of claim 4 , wherein the light-absorbing layer has an absorption coefficient in the range of about 0.01 to about 0.05.

12. The organic light emitting device of claim 4 , wherein the light-absorbing layer is formed of TiO 2 , Ta 2 O 5 or Nb 2 O 5 .

13. The organic light emitting device of claim 4 , wherein the light-absorbing layer has a thickness in the range of about 50 nm to about 1 μm.

14. The organic light emitting device of claim 1 , wherein the diffraction grating has protrusions shaped of a line, a rectangular pillar or a cylinder.

15. The organic light emitting device of claim 14 , wherein a pitch between the protrusions of the diffraction grating is approximately ¼ to 4 times a wavelength of light generated from the light emitting portion.

16. The organic light emitting device of claim 1 , wherein the first electrode is formed of ITO, IZO, ZnO, or In 2 O 3 .

17. The organic light emitting device of claim 1 , wherein the second electrode is formed of at least one of the following: Li, Ca, Al, Ag, and Mg.

18. A method of manufacturing an organic light emitting device, comprising:

forming a low-refractive layer on a substrate, wherein the low-refractive layer has a refractive index less than that of the substrate;

forming a diffraction grating on the low-refractive layer; and

forming a pixel layer having a first electrode, a second electrode and a light emitting portion interposed between the first electrode and the second electrode and having at least an emission layer.

19. A method of manufacturing an organic light emitting device, comprising:

forming a light-absorbing layer on a substrate;

forming a low-refractive layer on the light-absorbing layer, wherein the low-refractive layer has a refractive index less than that of the substrate;

forming a diffraction grating on the low-refractive layer; and

forming a pixel layer having a first electrode, a second electrode and a light emitting portion interposed between the first electrode and the second electrode and having at least an emission layer.

20. The method of claim 18 , wherein the diffraction grating is formed by patterning a plane of the low-refractive layer located in a direction of the light emitting portion.

21. The method of claim 20 , wherein the patterning comprises coating a photoresist layer on the low-refractive layer and patterning the resultant structure with the use of an electron beam method or a laser hologram method.