| abstract |
A composition suitable for printing of an opto-electrical device comprises a semiconducting hole transport material, hole injection material, light-emitting polymer material, electron transport material, or electron injection layer, a first solvent and a second solvent wherein the solvents are miscible with one another, the first solvent has a lower boiling point than the second solvent and the hole transport material has a higher solubility in the first solvent than in the second solvent. The second solvent has a dielectric constant in the range from 1 to 2.2 or from 20 to 32 and the first solvent has a dielectric constant in the range of from above 2.2 and to below 20. The first solvent is any of cyclohexylbenzene, methylanisole, methylbenzoate, butylbenzoate, ethyl benzoate, propyl benzoate, ethylanisole, dimethylanisole, anisole, hexylbenzene, heptylbenzene, octylbenzene, and the second solvent is dicyclohexyl monohexylcyclohexane, or monooctylcyclohexane. |