Donor substrate for laser induced thermal imaging and method of fabricating organic light emitting diode using the same
View Patent ↗Provided are a donor substrate for laser induced thermal imaging (LITI) and a method of fabricating an organic light emitting diode (OLED) using the same, which can prevent a transferred emission layer from being damaged by heat and thus prevent wrinkles from forming on the surface thereof. The donor substrate includes a base layer, a light-to-heat conversion layer disposed on the base layer, a first transfer layer disposed on the light-to-heat conversion layer and including an organic layer, an inorganic layer, or a double layer thereof, and a second transfer layer disposed on the first transfer layer and including an emission layer. The first transfer layer has an absolute value of lowest unoccupied molecular orbital energy level of 2.6 to 3.0 eV and a band gap energy of 2.8 to 3.4 eV.
1. A donor substrate for laser induced thermal imaging, comprising:
a base layer;
a light-to-heat conversion layer disposed on the base layer;
a first transfer layer disposed on the light-to-heat conversion layer and including an organic layer, an inorganic layer, or a double layer of an organic layer and an inorganic layer, the first transfer layer having an absolute value of lowest unoccupied molecular orbital energy level of 2.6 eV to 3.0 eV and a band gap energy of 2.8 eV to 3.4 eV; and
a second transfer layer disposed on the first transfer layer and including an organic light emitting host material.
2. The donor substrate of claim 1 , wherein the organic layer of the first transfer layer includes an organic light emitting host material.
3. The donor substrate of claim 2 , wherein the organic light emitting host material of the organic layer of the first transfer layer includes a blue light emitting host material.
4. The donor substrate of claim 2 , wherein the organic light emitting host material of the organic layer of the first transfer layer includes one selected from the group consisting of 4,4′-bis(2,2′-diphenylvinyl)-1,1′-biphenyl (DPVB), spiro-DPVB, distyrylarylene (DSA), distyrylarylene derivatives, distyrylbenzene (DSB), distyrylbenzene derivatives, carbazole derivatives, and triarylamine derivatives.
5. The donor substrate of claim 1 , wherein, if the first transfer layer includes the organic layer, the first transfer layer has a thickness of 30 Å to 300 Å.
6. The donor substrate of claim 1 , wherein, if the first transfer layer includes the inorganic layer or the double layer of the organic layer and the inorganic layer, the first transfer layer has a thickness of 30 Å to 50 Å.
7. A donor substrate for laser induced thermal imaging, comprising:
a base layer;
a light-to-heat conversion layer disposed on the base layer;
a first transfer layer disposed on the light-to-heat conversion layer and including an organic layer, an inorganic layer, or a double layer of an organic layer and an inorganic layer, the first transfer layer having an absolute value of lowest unoccupied molecular orbital energy level of 2.6 eV to 3.0 eV and a band gap energy of 2.8 eV to 3.4 eV; and
a second transfer layer disposed on the first transfer layer and including an organic light emitting host material and an organic light emitting dopant material.
8. The donor substrate of claim 7 , wherein the organic layer of the first transfer layer includes an organic light emitting host material.
9. The donor substrate of claim 8 , wherein the organic light emitting host material of the organic layer of the first transfer layer includes a blue light emitting host material.
10. The donor substrate of claim 8 , wherein the organic light emitting host material of the organic layer of the first transfer layer includes one selected from the group consisting of 4,4′-bis(2,2′-diphenylvinyl)-1,1′-biphenyl (DPVB), spiro-DPVB, distyrylarylene (DSA), distyrylarylene derivatives, distyrylbenzene (DSB), distyrylbenzene derivatives, carbazole derivatives, and triarylamine derivatives.
11. A method of fabricating an organic light emitting diode, comprising:
providing a substrate on which a first electrode is formed;
positioning a donor substrate, which includes a base layer, a light-to-heat conversion layer disposed on the base layer, a first transfer layer disposed on the light-to-heat conversion layer and including an organic layer, an inorganic layer, or a double layer of an organic layer and an inorganic layer, and a second transfer layer disposed on the first transfer layer and including an organic light emitting host material, the first transfer layer having an absolute value of lowest unoccupied molecular orbital energy level of 2.6 eV to 3.0 eV and a band gap energy of 2.8 eV to 3.4 eV, the second transfer layer facing the substrate;
irradiating a predetermined region of the base layer of the donor substrate with a laser beam to transfer a predetermined region of the first transfer layer and a predetermined region of the second transfer layer, which are formed on the predetermined region of the base layer, onto the substrate; and
forming a second electrode on the transferred first transfer layer.
12. The method of claim 11 , wherein the organic layer of the first transfer layer includes an organic light emitting host material.
13. The method of claim 12 , wherein the organic light emitting host material includes a blue light emitting host material.
14. The method of claim 12 , wherein the organic light emitting host material includes one selected from the group consisting of 4,4′-bis(2,2′-diphenylvinyl)-1,1′-biphenyl (DPVB), spiro-DPVB, distyrylarylene (DSA), distyrylarylene derivatives, distyrylbenzene (DSB), distyrylbenzene derivatives, carbazole derivatives, and triarylamine derivatives.
15. The method of claim 11 , wherein, if the first transfer layer includes the organic layer, the first transfer layer has a thickness of 30 Å to 300 Å.
16. The method of claim 11 , wherein, if the first transfer layer includes the inorganic layer or the double layer of the organic layer and the inorganic layer, the first transfer layer has a thickness of 30 Å to 50 Å.