Patent ID: 7635777

Claim:
A light emitting device comprising: at least one electrode, at least one hole injection layer, at least one light emissive layer; wherein the emissive layer comprises a polymer having structural units II the polymer is selected from the group consisting of polyesters, polycarbonates, polyethers, polyetherimides, polyaryletherketones, polyarylethersulfones and polyestercarbonates; R 1 , R 2 , and R 4 are independently at each occurrence a C 1 -C 20 aliphatic radical, a C 3 -C 20 aromatic radical, or a C 3 -C 20 cycloaliphatic radical; R 3 and R 5 are independently at each occurrence hydrogen, a C 1 -C 20 aliphatic radical, a C 3 -C 20 aromatic radical, or a C 3 -C 20 cycloaliphatic radical; and a, b and d are independently 0 or an integer ranging from 1 to 3.