Patent ID: 7666525

Claim:
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.