Formulation of an organic functional material comprising a siloxane solvent

A process for the preparation of an electroluminescent device, wherein at least one layer of the electroluminescent device is prepared by depositing a formulation containing at least one organic functional material and at least a first and a second solvent, wherein the first solvent is a cyclosiloxane in an amount in the range from 1 to 50 vol.-%, based on the total amount of solvents in the formulation, wherein the content of the second solvent is in the range from 50 to 99 vol.-%, based on the total amount of solvents in the formulation, wherein the second solvent has a boiling point in the range from 150 to 350° C., and wherein the at least one organic functional material is selected from the group consisting of organic conductors, organic semiconductors, organic fluorescent compounds, organic phosphorescent compounds, organic light-absorbent compounds, organic light-sensitive compounds, organic photosensitisation agents, and organometallic complexes of transition metals, rare earths, lanthanides and actinides, on a surface and subsequently dried.