Blue light-emitting device and organic light emitting display including the same
View Patent ↗A blue light-emitting device, and an organic light-emitting display including the blue light-emitting device, has a non-resonance structure including a blue light-emitting layer between a reflective electrode and a transparent electrode, and thus has an excellent process margin, an excellent luminance characteristic even in a wide optical viewing angle, and a high color reproduction satisfying an sRGB blue standard.
1. A blue light-emitting device comprising:
a transparent electrode;
a reflective electrode facing the transparent electrode; and
an intermediate layer disposed between the transparent electrode and the reflective electrode, the intermediate layer comprising a blue light-emitting layer having a light-emitting zone from which light is emitted toward the reflective electrode, wherein a distance between the reflective electrode and the light-emitting zone of the blue light-emitting layer is such that light reflected at the reflective electrode having a wavelength close to a light emission wavelength peak of the blue light-emitting layer is dissipated.
2. The blue light-emitting device of claim 1 , wherein the intermediate layer further comprises:
a first functional layer disposed between the transparent electrode and the blue light-emitting layer; and
a second functional layer disposed between the reflective electrode and the blue light-emitting layer.
3. The blue light-emitting device of claim 2 , wherein the distance between the reflective electrode and the light-emitting zone corresponds to a thickness of the second functional layer, when the light-emitting zone is formed on an interface between the second functional layer and the blue light-emitting layer.
4. The blue light-emitting device of claim 2 , wherein the distance between the reflective electrode and the light-emitting zone corresponds to a sum of a thickness of the second functional layer and a thickness of the blue light-emitting layer, when the light-emitting zone is formed on an interface between the first functional layer and the blue light-emitting layer.
5. The blue light-emitting device of claim 1 , wherein the distance between the reflective electrode and the light-emitting zone is determined based on a phase shift value of the light reflected at the reflective electrode, and a wavelength of the dissipated light.
6. The blue light-emitting device of claim 1 , wherein the transparent electrode is an anode.
7. The blue light-emitting device of claim 1 , wherein the transparent electrode is a cathode.
8. The blue light-emitting device of claim 1 , wherein the distance between the reflective electrode and the light-emitting zone of the blue light-emitting layer is controlled to be at least 1000 Å.
9. The blue light-emitting device of claim 8 , wherein the distance is controlled to be at least 2000 Å.
10. The blue light-emitting device of claim 9 , wherein the distance is controlled to be at least 2900 Å.
11. The blue light-emitting device of claim 9 , further comprising a multi-layer extending between the reflective electrode and the blue light-emitting layer, wherein the distance is controlled to be at least Σd j , and
Σd j is calculated according to the following equation:
λ
=
2
π
(
2
∑
n
j
λ
d
j
)
(
π
·
q
-
δ
λ
)
,
d j denotes a thickness of a j-th layer in the multi-layer,
n jλ denotes a refraction index of the j-th layer in a wavelength λ, and
δ λ is a phase shift value in the wavelength λ,
q is a positive odd number, and
λ is a wavelength of the light emitted from the light-emitting zone.
12. An organic light-emitting display comprising:
a transparent substrate; and
a blue light-emitting device comprising a transparent electrode disposed on the transparent substrate, a reflective electrode facing the transparent electrode, and an intermediate layer disposed between the transparent electrode and the reflective electrode and comprising a blue light-emitting layer which emits light from a light-emitting zone towards the transparent substrate,
wherein a distance between the reflective electrode and the light-emitting zone of the blue light-emitting layer is such that light reflected at the reflective electrode toward the transparent substrate having a wavelength close to a light emission wavelength peak of the blue light-emitting layer is dissipated.
13. The organic light-emitting display of claim 12 , wherein the intermediate layer further comprises:
a first functional layer disposed between the transparent electrode and the blue light-emitting layer; and
a second functional layer disposed between the reflective electrode and the blue light-emitting layer.
14. The organic light-emitting display of claim 13 , wherein the distance between the reflective electrode and the light-emitting zone corresponds to a thickness of the second functional layer, when the light-emitting zone is formed on an interface between the second functional layer and the blue light-emitting layer.
15. The organic light-emitting display of claim 13 , wherein the distance between the reflective electrode and the light-emitting zone corresponds to a sum of a thickness of the second functional layer and a thickness of the blue light-emitting layer, when the light-emitting zone is formed on an interface between the first functional layer and the blue light-emitting layer.
16. An organic light-emitting display comprising:
a transparent substrate; and
a blue light-emitting device comprising a reflective electrode disposed on the transparent substrate, a transparent electrode facing the reflective electrode, and an intermediate layer disposed between the transparent electrode and the reflective electrode and comprising a blue light-emitting layer having a light-emitting zone which emits a light towards the transparent electrode,
wherein a distance between the reflective electrode and the light-emitting zone of the blue light-emitting layer is such that light reflected at the reflective electrode having a wavelength close to a light emission wavelength peak of the blue light-emitting layer is dissipated.
17. The organic light-emitting display of claim 16 , wherein the intermediate layer further comprises:
a first functional layer disposed between the transparent electrode and the blue light-emitting layer; and
a second functional layer disposed between the reflective electrode and the blue light-emitting layer.
18. The organic light-emitting display of claim 17 , wherein the distance between the reflective electrode and the light-emitting zone corresponds to a thickness of the second functional layer, when the light-emitting zone is formed on an interface between the second functional layer and the blue light-emitting layer.
19. The organic light-emitting display of claim 17 , wherein the distance between the reflective electrode and the light-emitting zone corresponds to a sum of a thickness of the second functional layer and a thickness of the blue light-emitting layer, when the light-emitting zone is formed on an interface between the first functional layer and the blue light-emitting layer.
20. A flat panel display comprising:
a transparent substrate; and
a blue light-emitting device disposed on the transparent substrate, the blue light-emitting device comprising a reflective electrode, a transparent electrode, and an intermediate layer disposed between the transparent electrode and the reflective electrode and comprising a blue light-emitting layer having a light-emitting zone which emits a light received at the transparent electrode,
wherein a distance between the reflective electrode and the light-emitting zone of the blue light-emitting layer is such that light reflected at the reflective electrode having a wavelength close to a light emission wavelength peak of the blue light-emitting layer is dissipated.
21. The flat panel display of claim 20 , wherein the distance between the reflective electrode and the light-emitting zone of the blue light-emitting layer is controlled to be at least 1000 Å.
22. The flat panel display of claim 21 , wherein the distance is controlled to be at least 2000 Å.
23. The flat panel display of claim 22 , wherein the distance is controlled to be at least 2900 Å.
24. The flat panel display of claim 20 , further comprising a functional layer extending between the reflective electrode and the blue light-emitting layer, wherein the distance is at least a thickness of the functional layer and is less than a sum of a combined thickness of the blue light-emitting layer and the functional layer.
25. The flat panel display of claim 24 , wherein the distance is at least 1000 Å.
26. The flat panel display of claim 20 , further comprising a multi-layer extending between the reflective electrode and the blue light-emitting layer, wherein
the distance is controlled to be least Σd j , and
Σd j is calculated according to the following equation:
λ
=
2
π
(
2
∑
n
j
λ
d
j
)
(
π
·
q
-
δ
λ
)
,
d j denotes a thickness of a j-th layer in the multi-layer,
n jλ denotes a refraction index of the j-th layer in a wavelength λ, and
δ λ is a phase shift value in the wavelength λ,
q is a positive odd number, and
λ is a wavelength of the light emitted from the light-emitting zone.