Electro‐active oligomers containing pendent carbazolyl or indolyl groups as host materials for OLEDs

Abstract

Oligoethers containing electroactive carbazolyl, indolyl or 2-phenylindolyl fragments were synthesized and characterized by NMR spectroscopy, elemental analysis and gel permeation chromatography. The oligomers represent amorphous materials of high thermal stability with glass transition temperatures of 107-161 C. The electron photoemission spectra of layers of the synthesized oligomers showed ionization potentials of 5.9-5.95 eV. Some of the derivatives were tested as host materials in phosphorescent OLEDs with iridium(III)

Carbazole-based polymers as hosts for solution-processed organic light-emitting diodes: Simplicity, efficacy

“…Best performances were obtained with P57, reaching the maximum CE of 19.7 cd/A and a maximum luminance of 1850 cd/m 2 . Authors do not limit their investigations to poly(ethers) and oligo(ethers) were also studied as hosts for FIrpic [158]. As main difference with the previous polymers, oligomers P63-P65 comprised two electroactive units attached by a flexible chain to the monomeric unit.…”

Twin compounds of phenylethenyl substituted indole as efficient materials for electroluminescent devices

“…The values of T g of the synthesized materials could be compared M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 7 with those of earlier described indole containing derivatives. It was observed that the twin derivatives lower T g then polymers containing isolated indolyl fragments (T g = 107-161 o C) [24]. On the other hand the glass transition temperatures of the synthesized derivatives are compareble to that of branched low-molar-mass materials containing indolyl chromophores [25].…”

“…Commercially available indole-3-carboxaldehyde (1) was firstly used for preparation of the key starting compound-1,4-di(3-formylindol-1-yl)butane (2) by the similar procedure as described in literature [28]. The [24]. On the other hand the thermal stability of the synthesized derivatives is rather close to that of branched low-molarmass materials containing indolyl chromophores [25].…”

“…We have synthesized earlier series of hole-transporting indole-based derivatives. It was observed that the new derivatives demonstrate suitable charge injecting and transporting properties for their application in hole transporting lyers or for hole transporting host materials [24,25]. In this work, we have designed and synthesized new indole based materials containing two phenylvinyl substituted indole fragments, which were expected to show enhanced hole injection and transport properties and to be suitable as hole transporting materials for multilayer OLEDs.…”

Highly efficient bipolar host material based-on indole and triazine moiety for red phosphorescent light-emitting diodes

“…[20][21][22][23] It was reported that, indole type materials, which also possess high triple energy level and exceptional hole transporting properties, would be the potential host material for PHOLEDs. [24] Grigalevicius et al reported a series of indole-based polymer host materials with high thermal stability. The device based on a polyether containing 2-phenylindol-1-yl moieties achieved the best performance with maximum power efficiency of 8.46 lm/W and current efficiency of 718 cd/m 2 .…”