Patent ID: 8586209

Claim:
A composition for ink jet printing an opto-electrical device, which composition comprises a solution-processable host material, a metal complex, and a solvent, wherein the viscosity of the composition exceeds 16 mPa·s at 20° C. and which composition has a solids content of at least 1% by weight of the composition, wherein the host material is a host polymer comprising a co-polymer having a first repeat unit selected from the group consisting of optionally substituted fluorene, optionally substituted spirofluorene, optionally substituted indenofluorene, optionally substituted phenylene, and optionally substituted oligo-phenylene, and a further repeat unit comprising an optionally substituted triarylamine as shown in the following formula: in which each Ar is the same or different and independently represents an optionally substituted aryl or heteroaryl and any two Ar groups may be directly linked by a divalent group or a single bond; —(CR 4 R 5 ) n or —Ar 1 —(CR 4 R 5 ) n —Ar 2 — in which R 4 and R 5 are independently selected from hydrogen or a substituent, n is from 1 to 10, and Ar 1 and Ar 2 are independently selected from optionally substituted aryl or heteroaryl, and wherein the metal complex comprises a metal selected from the group consisting of ruthenium, rhodium, palladium, rhenium, osmium, iridium, platinum, and gold, and wherein the solvent is selected from the group consisting of phenylnonane, 4-methylanisole, optionally substituted benzoates, and mixtures thereof.