Organic electroluminescent device using a mixture of high and low molecular light-emitting substance as a light-emitting substance
View Patent ↗An organic EL device in which light-emitting efficiency, color purity and laser induced thermal imaging characteristics are improved by providing with an organic EL device comprising a first electrode, a hole transport layer, a light-emitting layer, and a second electrode, wherein the light-emitting layer uses a mixture of an optically active low molecular electric charge transport material and a high molecular light-emitting substance.
1. An organic EL device, comprising:
a first electrode which is a cathode encapsulated with a glass substrate;
a hole transport layer;
a light-emitting layer; and
a second electrode;
wherein the light-emitting layer uses a mixture of an optically active low molecular electric charge transport material and a high molecular light-emitting substance, and the light-emitting layer is patterned to an edge roughness of 5 to 8 microns.
2. An organic EL device comprising:
a first electrode;
a hole transport layer;
a light-emitting layer; and
a second electrode;
wherein the light-emitting layer uses a mixture of an optically active low molecular electric charge transport material and a high molecular light-emitting substance,
wherein the light-emitting layer is patterned to an edge roughness of 8 microns or less.
3. The organic EL device according to claim 2 , wherein the low molecular electric charge transport material is one of: carbazole, aryl amine, starburst and oxadiazole.
4. The organic EL device according to claim 3 , wherein the carbazole based material is 4-4′-N-N′-dicarbazole-biphenyl (CBP).
5. The organic EL device according to claim 3 , wherein the aryl amine based material is N,N′-bis-1-naphthyl-diphenyl-1,1′-biphenyl-4,4′-diamine (α-NPB).
6. The organic EL device according to claim 3 , wherein the starburst based material is a material selected from the group consisting of 4,4′,4″-tri(N-carbazole)-triphenylamine (TCTA), 4,4′,4″-tris(N-3-methyl phenyl amino)-triphenylamine (m- MTDATA), and 1,3,5-tris(N,N-bis-(4-methoxy-phenyl-aminophenyl)-benzene (TDAPB).
7. The organic EL device according to claim 3 , wherein the oxadiazole based material is 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,2,4-oxadiazole.
8. The organic EL device according to claim 2 , wherein a weight ratio of a weight of the low molecular electric charge transport material to a total weight of the light-emitting layer is in a range of 0.1 to 0.9.
9. The organic EL device according to claim 2 , wherein the high molecular light-emitting substance is a material selected from polyfluorene (PFO), polyspiro and PPV (poly phenylene vinylene).
10. The organic EL device according to claim 2 , wherein the light-emitting layer further comprises a high molecular matrix.
11. The organic EL device according to claim 10 , wherein the high molecular matrix is an optically inert high molecular material selected from a group consisting of polystyrene, poly(4-methylstyrene), poly(α-methyl styrene), polymethylmetacrylate (PMMA), polyethylmetacrylate, poly(vinyl pyridine), polyphenyleneoxide (PPO), styrene-butadiene block copolymer, styrene-metacrylic acid ester copolymer, styrene-methylmetacrylate copolymer, polycarbonate, polyethyleneterephthalate, polyestersulfonate, polysulfonate, polyacrylate, polyimide fluoride, transparent fluorocarbon resin, and transparent acryl based resin.
12. The organic EL device according to claim 10 , wherein a weight ratio of a weight of the low molecular electric charge transport material to a total weight of the light-emitting layer is in a range of 0.1 to 0.9.
13. The organic EL device according to claim 2 , wherein the organic EL device further comprises one material selected from the group consisting of fluorene, phenylene, and anthracene low molecular light-emitting substances.