Organic electroluminescent device and method for fabricating the same
An exemplary embodiment of the present invention provides an organic electroluminescent device including a substrate, a first electrode, one or more organic material layers, and a second electrode in a sequentially deposited form, wherein a light scattering layer is provided between the substrate and the first electrode, and includes a cholesteric liquid crystal layer including a liquid crystal vertically aligned to the substrate, and a method for fabricating the same.
1. An organic electroluminescent device comprising a substrate, a first electrode, one or more organic material layers, and a second electrode in a sequentially deposited form,
wherein a light scattering layer is provided between the substrate and the first electrode,
wherein the light scattering layer comprises a cholesteric liquid crystal layer including a liquid crystal in which a helix axis of the liquid crystal makes an acute angle with the substrate, and
wherein a refractive index of the cholesteric liquid crystal layer is more than 1.52.
2. The organic electroluminescent device according to claim 1 , wherein the cholesteric liquid crystal layer includes the liquid crystal in which a helix axis of the liquid crystal makes an angle equal to 0° or more and less than ±90° with the substrate.
3. The organic electroluminescent device according to claim 1 , wherein the cholesteric liquid crystal layer has a haze value of 30% or more.
4. The organic electroluminescent device according to claim 1 , wherein the cholesteric liquid crystal layer includes the liquid crystal in which a helix axis of the liquid crystal makes an angle of 0° to ±30° with the substrate.
5. The organic electroluminescent device according to claim 4 , wherein the liquid crystal in which a helix axis of the liquid crystal makes an angle of 0° to ±30° with the substrate is 50% or more in the liquid crystal forming the cholesteric liquid crystal layer.
6. The organic electroluminescent device according to claim 1 , wherein the light scattering layer includes a base member and the cholesteric liquid crystal layer disposed on the base member.
7. The organic electroluminescent device according to claim 1 , wherein the cholesteric liquid crystal layer is manufactured from a composition including i) a liquid crystal material, ii) a chiral dopant and iii) a solvent.
8. The organic electroluminescent device according to claim 7 , wherein i) the liquid crystal material includes a liquid crystal monomer and a polymerization initiator.
9. The organic electroluminescent device according to claim 8 , wherein the liquid crystal monomer includes a reaction group that can perform photocuring or heat curing.
10. The organic electroluminescent device according to claim 7 , wherein i) the liquid crystal material includes one or more selected from the liquid crystal monomers represented by the following Formula 1 to Formula 4:
11. The organic electroluminescent device according to claim 8 , wherein on the basis of 100 parts by weight of i) the liquid crystal material, a content of the liquid crystal monomer is 80 to 99.5 parts by weight and a content of the polymerization initiator is 0.05 to 20 parts by weight.
12. The organic electroluminescent device according to claim 7 , wherein on the basis of 100 parts by weight of i) the liquid crystal material, a content of ii) the chiral dopant is 0.001 to 20 parts by weight.
13. The organic electroluminescent device according to claim 7 , wherein the composition further includes a surfactant.
14. The organic electroluminescent device according to claim 13 , wherein on the basis of 100 parts by weight of i) the liquid crystal material, a content of the surfactant is 0.01 to 5 parts by weight.
15. The organic electroluminescent device according to claim 6 , wherein an alignment film is further included between the base member and the cholesteric liquid crystal layer.
16. The organic electroluminescent device according to claim 1 , wherein a thickness of the cholesteric liquid crystal layer is 0.1 μm or more.
17. An organic electroluminescent device comprising a substrate, a first electrode, one or more organic material layers, and a second electrode in a sequentially deposited form,
wherein a light scattering layer is provided between the substrate and the first electrode,
wherein the light scattering layer comprises a cholesteric liquid crystal layer having a haze value of 30% or more, and
wherein a refractive index of the cholesteric liquid crystal layer is more than 1.52.
18. The organic electroluminescent device according to claim 17 , wherein the cholesteric liquid crystal layer includes the liquid crystal in which a helix axis of the liquid crystal makes an angle of 0° to ±30° with the substrate.
19. The organic electroluminescent device according to claim 1 , wherein the cholesteric liquid crystal layer is manufactured from a composition including i) a liquid crystal material, ii) a chiral dopant and iii) a solvent.