Stability OLED materials and devices

摘要

Organic light emitting materials and devices comprising phosphorescent metal complexes comprising ligands comprising aryl or heteroaryl groups substituted at both ortho positions are described. An organic light emitting device, comprising: an anode; a hole transport layer; an organic emissive layer comprising an emissive layer host and an emissive dopant; an electron impeding layer; an electron transport layer; and a cathode disposed, in that order, over a substrate.

主权项

1. A phosphorescent compound, wherein the phosphorescent compound is a neutral metal complex of a bidentate, tridentate, tetradentate, pentadentate, or hexadentate ligand;wherein the ligand comprises:
a first ring directly bonded to the metal, the first ring being an imidazole; a second ring as a substitution on the first ring and not directly bonded to the metal, the second ring being an aryl or heteroaryl ring substituted at both ortho positions by groups other than H or halide, wherein the ortho position substitutions do not form a fused ring with the second ring; a third ring as a substitution on the first ring, the third ring being an aryl or heteroaryl ring directly bonded to the metal; wherein the metal complex is an organometallic complex; wherein the metal is selected from the group consisting of the non-radioactive metals with atomic numbers greater than 40; and wherein the photoluminescent emission spectrum of the phosphorescent compound is blue-shifted compared to a comparative compound of identical structure except without the ortho position substitutions on the second ring.