Organic light emitting diode device
An organic light emitting diode device includes: a first substrate; a first electrode on the first substrate; an organic light emitting layer on the first electrode; a second electrode on the organic light emitting layer; and a capping layer on the second electrode. The capping layer may include at least one high refractive-index layer and at least two low refractive-index layers having thicknesses different from each other.
1. An organic light emitting diode device comprising:
a first substrate;
a first electrode on the first substrate;
an organic light emitting layer on the first electrode;
a second electrode on the organic light emitting layer; and
a capping layer on the second electrode; the capping layer including a first high refractive-index layer, a first low refractive-index layer, and a second low refractive-index layer, wherein
the first high refractive-index layer has a thickness greater than the first low refractive-index layer, and
the first low refractive-index layer has a thickness greater than the second low refractive-index layer,
wherein the first high refractive-index layer has a refractive index of about 1.8 to 2.5.
2. The organic light emitting diode device as claimed in claim 1 , wherein the first low refractive-index layer, the first high refractive-index layer, and the second low refractive-index layer are sequentially stacked on the second electrode.
3. The organic light emitting diode device as claimed in claim 1 , wherein
the first low refractive-index layer and the second low refractive-index layer have a refractive index of about 1.3 to 1.75.
4. The organic light emitting diode device as claimed in claim 1 , wherein:
the first high refractive-index layer has a thickness of about 10 to 100 nm, and
the first low refractive-index layer and the second low refractive-index layer have a thickness of about 5 to 30 nm.
5. The organic light emitting diode device as claimed in claim 1 , wherein the capping layer includes a second high refractive-index layer and a third low refractive-index layer.
6. The organic light emitting diode device as claimed in claim 5 , wherein the first low refractive-index layer, the first high refractive-index layer, the second low refractive-index layer, the second high refractive-index layer, and the third low refractive-index layer are sequentially stacked on the second electrode.
7. The organic light emitting diode device as claimed in claim 6 , wherein:
the first low refractive-index layer has a thickness greater than those of the second low refractive-index layer and the third low refractive-index layer, and
the second low refractive-index layer has a thickness greater than that of the third low refractive-index layer.
8. The organic light emitting diode device as claimed in claim 5 , wherein:
the first high refractive-index layer and the second high refractive-index layer have a refractive index of about 1.8 to 2.5, and
the first to third low refractive-index layers have a refractive index of about 1.3 to 1.75.
9. The organic light emitting diode device as claimed in claim 5 , wherein:
the first high refractive-index layer and the second high refractive-index layer have a thickness of about 10 to 100 nm, and
the first to third low refractive-index layers have a thickness of about 5 to 30 nm.
10. The organic light emitting diode device as claimed in claim 1 , further comprising a second substrate opposed to the first substrate.
11. The organic light emitting diode device as claimed in claim 10 , further having a space between the capping layer and the second substrate.
12. The organic light emitting diode device as claimed in claim 11 , wherein the space is filled with a gas having a refractive index lower than a refractive index of an uppermost layer of the capping layer.
13. The organic light emitting diode device as claimed in claim 12 , wherein the gas is air.
14. The organic light emitting diode device as claimed in claim 10 , further comprising a filling member between the capping layer and the second substrate.
15. The organic light emitting diode device as claimed in claim 14 , wherein the filling member has a refractive index that matches that of the second substrate.
16. The organic light emitting diode device as claimed in claim 1 , wherein the first and second low refractive-index layers have a same refractive index.
17. The organic light emitting diode device as claimed in claim 1 , wherein the first high refractive-index layer is thicker than either of the first and second low refractive-index layers.