Patent ID: 7982391

Claim:
An organic electroluminescent device comprising two electrodes and at least one organic compound layer disposed between the electrodes, wherein a luminescent layer comprising a laminated construction comprising at least two alternating layers in total where one layer includes a fluorescent compound and the other layer includes an amplifying agent, is included in the organic compound layers, at least one of the organic compound layers comprises the amplifying agent, the fluorescent compound emits fluorescent light upon application of voltage, the amplifying agent is capable of amplifying a number of singlet excitons formed upon the application of voltage and of amplifying luminescence intensity upon the application of voltage, and an amount of the amplifying agent is such an amount that at least 51% of light components emitted by the device upon the application of voltage is fluorescent light, wherein the fluorescent compound is a compound represented by the following formula (7): wherein in Formula (7), R 71 and R 72 bond to one another to form a benzene ring resulting a coumarin skeleton that is further substituted with a dialkylamino group at the 7-position of the coumarin skeleton, R 73 represents a hydrogen atom, and R 74 represents a five membered heterocyclic ring as follows: wherein X is S; wherein a host material is contained in both the layer including the fluorescent compound and the layer including the amplifying agent, and wherein the laminated construction comprises at least four alternating layers.