Organic electroluminescent device comprising a polymer layer containing a polymide having triphenylamine derivative unit
View Patent ↗An organic EL device has a layer containing a polyimide having a triphenylamine derivative (TPD) unit. The use of the polyimide as a polymer layer material can ensure solvent selectivity in coating the light-emitting layer and the organic EL device exhibits good luminance efficiency even after a prolonged period use.
1. An organic electroluminescent device, comprising:
a first electrode;
a second electrode;
a light emitting layer between the first electrode and the second electrode;
a hole transport layer between the light emitting layer and the first electrode;
a hole injection layer between the hole transport layer and the first electrode; and
a polymer layer comprising a polyimide having a triphenylamine derivative unit represented by Formula 1 between the hole transport layer and the light emitting layer:
where X is a tetravalent aromatic hydrocarbon group, n is an integer of 1 to 10,000, and Y is
where R1 and R2 are each independently a hydrogen or a monovalent C 1 -C 15 organic group, W is a bond or
where Ar is an aryl group, A is a bond or an aryl group, and Z is a bond or an arylenyl group.
2. The organic electroluminescent device of claim 1 , wherein at least one of the hole transport layer and the hole injection layer is a poly(3,4-ethylenedioxythiophen)/polystyrene sulfonate layer.
3. The organic electroluminescent device of claim 1 , wherein Y is any one selected from the group consisting of:
where each R1 and each R2 are each independently a hydrogen or a monovalent C 1 -C 15 organic group.
4. The organic electroluminescent device of claim 1 , wherein X is any one selected from the group consisting of:
5. The organic electroluminescent device of claim 1 , wherein the polymer layer has a thickness in the range of about 10 nm to about 50 nm.
6. The organic electroluminescent device of claim 1 , wherein the polyimide is represented by Formula 2:
where X is a tetravalent aromatic hydrocarbon group, n is an integer of 1 to 10,000, and each R 1 and each R 2 are each independently a hydrogen or a monovalent C 1 -C 15 organic group.
7. The organic electroluminescent device of claim 1 , wherein n is 1 to 1,000.
8. The organic electroluminescent device of claim 1 , wherein the monovalent C 1 -C 15 organic group is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted heteroalkyl group, or a substituted or unsubstituted heteroaryl group.
9. A polyimide for an interlayer of an organic electroluminescent device, the polyimide represented by Formula 1:
where X is selected from the group consisting of the following formulae:
Y is where R 1 and R 2 are each independently a hydrogen or a monovalent C 1 -C 15 organic group, W is a bond, and Z is a bond or an arylenyl group;
N is an integer of 1 to 10,000.
10. The polyimide of claim 9 , wherein X is
11. An organic electroluminescent device having a polymer layer of the polyimide of claim 9 .
12. A method of making a polymer layer for an organic electroluminescent device, the method comprising the utilizing the polyimide of claim 9 for the polymer layer.
13. A polyimide for an interlayer of an organic electroluminescent device, the polyimide represented by Formula 2 prepared by reacting a tetracarboxylic dianhydride represented by Formula 3 with a triphenylamine derivative represented by Formula 4:
wherein n is an integer from 1 to 10,000, each R 1 and each R 2 are each independently a hydrogen or a monovalent C 1 -C 15 organic group, and X is selected from the group consisting of: