A tris ?-diketonate europium(III) complex based OLED fabricated by thermal evaporation method displaying efficient bright red emission

A new tris ?-diketonate europium(III) complex [Eu(btfa) 3 Py-Im] ( Eu-1 ) (4,4,4-trifluoro-1-phenyl-1,3-butanedione (btfa) and 2-(2-pyridyl)benzimidazole (Py-Im)] has been synthesized structurally characterized. single crystal X-ray diffraction analysis shows that is octacoordinated the coordination sphere composed of a EuO 6 N 2 core with trigonal dodecahedral (D 2d geometry. The photophysical properties were analysed in detail help experimental PL data theoretical modelling, energy transfer rates calculated, an mechanism proposed for . used as emitting layer (EML) to fabricate organic light diodes (OLEDs). Eight OLEDs, which four single-EML double-EML varying doping concentration, fabricated via thermal evaporation method using EML. Under optimum conditions highly monochromatic bright red emission (CIE x,y = 0.640, 0.311) brightness (B) 896 cd/m , current efficiency (? c 2.26 cd/A, power p 1.92 lm/W external quantum (EQE) 1.6% at very low V turn-on 3.4 was obtained. • Photophysical experimentally theoretical. excellent properties. Pure OLEDs emitter. Device showed improved EL performance than analogous europium complexes.