An organic electroluminescent device comprising a plasticiser

摘要

A light emitting device comprising an organic electroluminescent material 3 with a glass transition temperature substantially at or below an intended normal operation temperature of the device e.g. 20 - 120oC. The organic electroluminescent material may be a polymer comprising at least one fluorine, arylene, phenylene, indenofluorene or spirofluorene repeat unit and a plasticizer residue comprising a polyfluorene or a phthalate such as dioctyl phthalate. The plasticizer helps control the glass transition temperature Tg. The organic electroluminescent material may comprise side chains of straight or branched C1 to C15 alkyl, alkenyl or alkynyl groups. The light emitting device is regenerated by heating the electroluminescent layer using a heater to a temperature equal to or above its glass transition temperature e.g. 60-200 oC.