Polymer light-emitting devices based on europium(III) complex with 11-bromo-dipyrido[3,2-a:2′,3′-c]phenazine

Abstract

Polymer light-emitting diodes (PLEDs) containing Eu(DBM)3(BrDPPz) (DBM is dibenzoylmethane, and BrDPPz is 11-bromo-dipyrido[3,2-a:2′,3′-c]phenazine) doped in a blend of poly(9,9-dioctylfluorene) (PFO) and 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PBD) as the host matrix are reported. Eu(DBM)3(BrDPPz) exhibited high thermal stability and intense UV-Vis absorption. Narrow-bandwidth red emission at 612 nm with a full width at half-maximum (FWHM) of 14.0 nm was observed from Eu(DBM) 3 (BrDPPz) in these double-layered PLEDs at dopant concentrations from 1 wt% to 8 wt%. For the PLED containing 1 wt% Eu(DBM) 3 (BrDPPz), a maximum luminance of 829 cd/m 2 at 153.5 mA/cm 2 , highest external quantum efficiency of 1.70% at 2.1 mA/cm 2 and maximum luminance of 0.74 cd/A at 4.31 mA/cm 2 were obtained. europium(III) complexes, electroluminescence, optophysical properties, polymer light-emitting diodes

Synthesis and Luminescence Properties of Rare Earth (Eu, Tb) Complexes of Octanoylphenylalanine

“…The emission of Tb 3+ is mainly from the 5 D4→ 7 FJ transition, which is located in the green light region. The emission of Eu 3+ mainly comes from the transition of 5 D0→ 7 FJ and is in the red region [4]. The luminescence mechanism of the two rare earth complexes can be preliminarily deduced by combining the ultraviolet absorption spectra and emission spectra, but further research is needed.…”

“…The research of rare earth luminescent materials mainly focuses on inorganic luminescent materials, such as rare earth ions and transition metal ions doped with various metal oxides, composite oxides etc. [4]. It is well known that rare earth ions have extreme small absorption in the visible and ultraviolet spectra range, as a consequence the luminescent intensity of inorganic rare earth luminescent materials is relatively low.…”

Excellent Electroluminescent Property of Eu3+-Induced Polystyrene-co-poly(acrylic acid) Aggregates (EIPAs) in Polymeric Light-Emitting Diodes

“…This method is straightforward and helped to prevent luminescence quenching due to concentration effects. However, compared to PLED devices prepared through vacuum deposition with Eu 3+ complexes, there are challenges, such as a noticeable decrease in external quantum efficiency (EQE) and brightness. − Therefore, various Eu 3+ complexes with different ligands, such as triphenylamine, carbazole, and oxadiazole, were designed and synthesized to achieve high device efficiency by promoting the transport of holes and electrons. ,− In terms of EQE and brightness, the best performances of PLED devices using Eu 3+ complexes as emitters prepared via the spin-coating technique are as follows: (1) Zhang et al showcased a PLED based on Eu­(FTA) 3 Phen (FTA = 4,4,4-trifluoro-1-phenyl-1,3-butanedione) with an EQE of 4.3%, and (2) Cao group presented a PLED based on Eu­(DBM) 3 (DPPZ) [DPPZ= (dipyrido­(3,2-a:2′,3′-c)­phenazine)] with a maximum brightness of 1783 cd/m 2 . Despite the advancements, incorporating Eu 3+ complexes into PLEDs still presents potential challenges in achieving high EQE and brightness.…”