Europium complex as a highly efficient red emitter in electroluminescent devices

Abstract

Several devices using a europium complex Eu͑TTA͒ 3 ͑DPPz͒(TTAϭ2-thenoyltrifluoroacetonate, DPPzϭdipyrido͓3,2-a:2Ј,3Ј-c͔phenazine) as dopant emitter were fabricated. The performances of these devices are among the best reported for devices incorporating a europium complex as a red emitter. One such device with structure TPD ͑50 nm͒/Eu:CBP ͑4.5%, 30 nm͒/BCP ͑30 nm͒/Alq ͑25 nm͒ exhibits an external quantum efficiency 2.1%, current efficiency 4.4 cd/A, power efficiency 2.1 lm/W, and brightness 1670 cd/m 2 .

Highly Improved Electroluminescence from a Series of Novel EuIII Complexes with Functional Single‐Coordinate Phosphine Oxide Ligands: Tuning the Intramolecular Energy Transfer, Morphology, and Carrier Injection Ability of the Complexes

“…However in the EL spectrum of F, the emission from Alq 3 at about 520 nm became more and more visible during voltage increase, which was also reported in previous work. [5,14,25] According to the energy-level schemes in Figure 12, it is clear that in devices D and E, because of the higher HOMO energy levels of 1 and 2, the hole cannot jump across energy gaps as big as % 1.5 eV to enter into Alq 3 even at breakdown voltages, so no emission from Alq 3 was observed. However, in F the lower HOMO energy level of 3 nearly halves the energy gap between hole-transporting NPB and hole-blocking BCP.…”

“…However, because of their higher T 1 energy level the positive energy transfer from T 1 levels of TAPO, NaDAPO, and CPPO to that of TTA becomes preponderant, and the reverse energy transfer from TTA to neutral ligands is restrained. Consequently, most of the triplet excited energy of these neutral ligands can be efficiently transferred to 5 D 0 of Eu III through the T 1 level of TTA. In brief, modification with chromophore groups reduces the S 1 levels of TAPO, NaDAPO, and CPPO to fit that of TTA much more, which improves the intramolecular singlet energy transfer in the complexes and increases the S 1 energy-transfer efficiency.…”

DNA Probe and Cleavage Studies Based on the Interaction between DNA and Yb, Er Complexes of 2‐[(Trifluoroaceto)aceto]thinophene‐piperidine Ligands

“…The entire system was cooled to room temperature and the aim complex Yb(TTA) 4 •HP was obtained. According to the same method, we got another aim complex, Er(TTA) 4 •HP starting from Er 2 O 3 . The yields of above complex products are 92% and 90% respectively.…”

“…2,3 Cheng et al have studied the europium complex Eu(TTA) 3 (DPPz) (DPPz ＝ dipyrido[3,2-a:2',3'-c]phenazine), Eu(TTA) 3 (DEP) (DEP ＝ 5-diethylamino-1,10-phenanthroline) as a red emitter and red dopants respectively in electroluminescent devices. 4 We know binding studies of transition metal complexes have become a very important field in the development of DNA molecule probes and chemotherapeutics in recent years. 5 In order to find anticancer or antineoplastic agents that can recognize and cleave DNA, people synthesized and developed many kinds of complexes, among which metals or ligands can be varied in an easily controlled way to facilitate the individual applications.…”

Silver nanoparticles embedded hybrid organometallic complexes: Structural interactions, photo-induced energy transfer, plasmonic effect and optical thermometry

“…[1][2][3][4][5] Their excellent optical properties such as large Stokes' shifted emission, high quantum yield, narrow bandwidth, long lived decay profile and mechanical flexibility offer promising applications in many fields such as sensors, in medical diagnostics, optical and electronic devices etc. [1][2][3][4][5][6][7][8][9][10] Lanthanide complexes are basically organo-metallic complexes, in which organic ligands and the rare-earth ion are bonded either through covalent or co-ordinate bonds. The recent trends in the field of lanthanide complexes are to introduce metal nanoparticles to tune its luminescent behavior and boost their efficiency for optical device applications.…”