Fabricating method of light emitting device and forming method of organic layer
A fabricating method of a light emitting device is provided. In the fabricating method, a substrate having a first electrode layer is provided. An organic film solution that includes an organic material, a solid medium, and a solvent is provided. The solid medium is capable of sublimation, and the organic material and the solid medium are mixed into the solvent. An organic film is formed on the first electrode layer by using the organic film solution. The solvent and the solid medium are removed to form an organic functional layer that has the organic material. A second electrode layer is formed on the organic functional layer.
1. A fabricating method of a light emitting device, comprising:
providing a substrate, the substrate comprising a first electrode layer;
providing a first organic film solution, the first organic film solution comprising a first organic material, a first solid medium, and a first solvent, wherein the first solid medium is sublimated under the atmospheric pressure at a sublimation temperature lower than 110° C., and the first organic material and the first solid medium are mixed into the first solvent;
disposing the first organic film solution on the first electrode layer;
forming a first organic film on the first electrode layer;
removing the first solvent in the first organic film to form a first solid film;
providing a second organic film solution, the second organic film solution comprising a second organic material, a second solid medium, and a second solvent, wherein the second solid medium is sublimated under the atmospheric pressure at a sublimation temperature lower than 110° C., and the second organic material and the second solid medium are mixed into the second solvent;
forming a second organic film on the first solid film by using the second organic film solution;
removing the second solvent in the second organic film to form a second solid film;
removing the first solid medium to form a first organic functional layer having the first organic material;
removing the second solid medium to form a second organic functional layer having the second organic material; and
forming a second electrode layer on the second organic functional layer.
2. The fabricating method as recited in claim 1 , wherein the first solid medium comprises naphthalene or aluminium acetylacetonate (Al(acac)3).
3. The fabricating method as recited in claim 1 , wherein the first organic material comprises a material of a hole injection layer, a material of a hole transporting layer, a material of an electron injection layer, a material of an electron transporting layer, or a material of an organic light emitting layer.
4. The fabricating method as recited in claim 1 , wherein the first organic functional layer comprises a hole injection layer, a hole transporting layer, an electron injection layer, an electron transporting layer, or an organic light emitting layer.
5. The fabricating method as recited in claim 1 , wherein the first solvent comprises tetrahydrofuran, dichloromethane, toluene, or acetone.
6. The fabricating method as recited in claim 1 , wherein the first solid medium in the first solid film and the second solid medium in the second solid film are sublimated in one heating step.
7. The fabricating method as recited in claim 1 , wherein the second organic material is different from the first organic material.
8. The fabricating method as recited in claim 1 , wherein the sublimation temperature of the first solid medium is substantially the same as the sublimation temperature of the second solid medium.
9. The fabricating method as recited in claim 1 , wherein the first organic functional layer and the second organic functional layer are selected from any two of a hole injection layer, a hole transporting layer, an organic light emitting layer, an electron injection layer, and an electron transporting layer.
10. The fabricating method as recited in claim 1 , further comprising forming a buffer layer on the first solid film before forming the second organic film, wherein the second organic film solution is formed on the buffer layer to form the second organic film, the buffer layer includes a third solid medium, and the third solid medium is sublimated under the atmospheric pressure at a sublimation temperature lower than 110° C.
11. The fabricating method as recited in claim 10 , wherein the sublimation temperature of the first solid medium, the sublimation temperature of the second solid medium, and the sublimation temperature of the third solid medium are substantially the same.
12. The fabricating method as recited in claim 10 , wherein the first solid medium, the second solid medium, and the third solid medium are sublimated in one heating step.
13. The fabricating method as recited in claim 1 , wherein a method of forming the first organic film on the first electrode layer comprises coating the first electrode layer with the first organic film solution.
14. The fabricating method as recited in claim 13 , wherein a method of coating the first electrode layer with the first organic film solution comprises a spin coating method or an inkjet method.
15. The fabricating method as recited in claim 2 , wherein the step of removing the first solid medium comprises:
removing the first solid medium by sublimation at a temperature and a pressure appropriate for the sublimation of naphthalene or aluminium acetylacetonate.