Electroluminescent characteristics of europium complex thin films prepared using a vacuum deposition technique

Electroluminescent (EL) devices based on organic materials have great interest due to their possible application for large-area flat-panel displays, for which they are attractive because of their multicolor-emission capability and their low operating voltage. In this study, the Electroluminescent (EL) and the current-voltage (I-V) character-istics of Eu(TTA) 3(phen) thin films with various thicknesses from 4 nm to 30 nm and with a structure of glass substrate/ITO/TPD/Eu(TTA) 3(phen)/AlQ 3/Al were investigated, where TPD, and AlQ 3 films were used as a hole- and electron-transporting materials, respectively. This structure showed a red EL spectrum with a λ max of 612 nm, which was almost the same as the PL spectrum of Eu(TTA) 3(phen). As the film thickness of Eu(TTA) 3(phen) decreased, the luminescent intensity of the device increased.