ORGANIC LIGHT-EMITTING DEVICE
An organic light-emitting device (OLED) which exhibits superior light extraction efficiency due to an extraction structure for dipole light generated from an organic light-emitting layer. The OLED includes a first glass substrate, a first electrode disposed on the first glass substrate, an organic light-emitting layer disposed on the first electrode, a second electrode disposed on the organic light-emitting layer, and a second glass substrate disposed on the second electrode. The second electrode has a composite electrode structure including a first transparent electrode layer and a second transparent electrode layer stacked on each other, the refractive index of the second transparent electrode layer being higher than the refractive index of the first transparent electrode layer.
1 . An organic light-emitting device comprising:
a first glass substrate;
a first electrode disposed on the first glass substrate;
an organic light-emitting layer disposed on the first electrode;
a second electrode disposed on the organic light-emitting layer; and
a second glass substrate disposed on the second electrode,
wherein the second electrode has a composite electrode structure including a first transparent electrode layer and a second transparent electrode layer stacked on each other, a refractive index of the second transparent electrode layer being higher than a refractive index of the first transparent electrode layer.
2 . The organic light-emitting device according to claim 1 , wherein the first transparent electrode layer is disposed at a side of the second glass substrate, and the second transparent electrode layer is disposed at a side of the organic light-emitting layer.
3 . The organic light-emitting device according to claim 2 , wherein the refractive index of the second transparent electrode layer ranges from 2.1 to 2.5.
4 . The organic light-emitting device according to claim 3 , wherein the second transparent electrode layer comprises Al- or Ga-doped ZnO or Nb-doped TiO 2 .
5 . The organic light-emitting device according to claim 4 , wherein the first transparent electrode layer comprises indium tin oxide.
6 . The organic light-emitting device according to claim 1 , wherein a thickness of the second electrode ranges from 50 to 200 nm.
7 . The organic light-emitting device according to claim 1 , comprising a plurality of the organic light-emitting layers which each alternate with interconnecting layers to form a tandem structure.
8 . An organic light-emitting device comprising:
a first glass substrate;
a first electrode disposed on the first glass substrate;
an organic light-emitting layer disposed on the first electrode;
a second electrode disposed on the organic light-emitting layer, wherein the second electrode has a composite electrode structure including a first transparent electrode layer and a second transparent electrode layer stacked on each other, a refractive index of the second transparent electrode layer being higher than a refractive index of the first transparent electrode layer;
a light extraction layer disposed on the second electrode; and
a second glass substrate disposed on the light extraction layer.
9 . The organic light-emitting device according to claim 8 , wherein the light extraction layer comprises:
a matrix layer; and
at least one light-scattering body disposed inside the matrix layer, the light-scattering body being made of a material, a refractive index of which is higher than a refractive index of the matrix layer.
10 . The organic light-emitting device according to claim 9 , wherein the refractive index of the light-scattering body is higher than the refractive index of the first transparent electrode layer.
11 . The organic light-emitting device according to claim 10 , wherein the first transparent electrode layer is disposed at a side of the light extraction layer, and the second transparent electrode layer is disposed at a side of the organic light-emitting layer.
12 . The organic light-emitting device according to claim 11 , wherein the light-scattering body is disposed inside a portion of the matrix layer that adjoins to the first transparent electrode layer.
13 . The organic light-emitting device according to claim 8 , wherein the refractive index of the second transparent electrode layer ranges from 2.1 to 2.5.
14 . The organic light-emitting device according to claim 13 , the second transparent electrode layer comprises Al- or Ga-doped ZnO or Nb-doped TiO 2 .
15 . The organic light-emitting device according to claim 14 , wherein the first transparent electrode layer comprises indium tin oxide.
16 . The organic light-emitting device according to claim 8 , wherein a thickness of the second electrode ranges from 50 to 200 nm.
17 . The organic light-emitting device according to claim 8 , comprising a plurality of the organic light-emitting layers which each alternate with interconnecting layers to form a tandem structure.