OLEDs based on an europium(IIIrpar; complex: {Tris(thenoyltrifluoroacetonate)[1,2,5]‐thiadiazolo[3,4‐f] [1,10]phenanthroline}europium(III)

Abstract

The contribution of radiative and non-radiative processes to the electroluminescence emission of OLEDs based on Eu-complex, {tris(thenoyltrifluoroacetone) [1,2,5]thiadiazolo[3,4f][1,10]phenanthroline} europium(III), [Eu(TTA) 3 TDZP], which acts as transporting and emitting layers, is investigated. The Eu-complex presented an intense photoluminescence with high color purity in the red region, characteristic of the Eu(III) 5 D 0 → 7 F 2 narrow line transition. However, when used in a double-layered OLED its electroluminescence showed additional undesired broad bands, which can be attributed to the possible electrophosphorescence of the ligand and to an inefficient energy transfer from the organic ligand to the Eu(III). The characteristic narrow lines could be achieved using a co-deposited active layer with the Eu-complex acting as a dopant in a matrix comprised of 4,4′bis(carbazol-9-yl)biphenyl (CBP).

Review on the Electroluminescence Study of Lanthanide Complexes

“…In addition, Sun, Pereira and Gallardo et al introduced conjugated pyrazine, thiadiazole and selenadiazole rings into phen, respectively and synthesized a series of europium(III) complexes Eu‐4 to Eu‐11 ( Scheme ). Among which the device based on Eu‐5 showed the best performance, with a maximum brightness of 1670 cd m −2 , a maximum CE of 4.38 cd A −1 and a maximum EQE of 2.05%.…”

Magnetism Studies of Bis(acyl)phosphide-Supported Eu3+and Eu2+Complexes

“…Molecular Eu complexes have continued to gain popularity due to their long-lived luminescence and magnetic properties, making them ideal for numerous applications such as single-molecule magnets and light-emitting diodes. − Many of these complexes are supported by Acac-derived ligands (Acac = acetylacetonate or β-diketonate), with there being over 500 Eu complexes bearing at least three Acac-derived ligands and one neutral supporting ligand in the Cambridge Crystallographic Data Centre (CCDC) . Despite the popularity of Eu 3+ molecular complexes, there have been no reactivity studies of BAP (BAP = bis­(acyl)­phosphide) ligands toward any lanthanide metals.…”

An Approach for Measuring the Dielectric Strength of OLED Materials

“…In addition, the devices with BPhen as an organic layer show higher dielectric strength as compared to devices with CBP organic layers. The reasons behind this may be: (i) highest occupied molecular orbital (HOMO) level of BPhen is deeper (6.3 eV); (ii) high electron mobility of BPhen; and (iii) the bipolar nature of CBP [ 23 , 24 , 25 , 26 ].…”