An organic electroluminescent (EL) device comprising at least one luminescent layer of an organic compound, the luminescent layer being positioned between a cathode electrode and an anode electrode opposed to the cathode electrode, and an organic layer positioned adjacent to the cathode electrode, in...http://www.google.es/patents/US7326473?utm_source=gb-gplus-sharePatente US7326473 - Organic electroluminescent devices
