The effect of bipolar charge transport of derivatives of 1-phenyl-1H-benzo[d]imidazole with horizontal molecular orientation on the performance of OLEDs based on thermally activated delayed fluorescence or phosphorescence /

Simas Macionis; Ehsan Ullah Rashid; Jurate Simokaitiene; Rita Butkute; Oleksandr Bezvikonnyi; Dmytro Volyniuk; Dalius Gudeika; Tien-Lung Chiu; Jiun-Haw Lee; Zi-Wen Su; Chia-Hsun Chen; Ruta Budreckiene; Mariia Stanitska; Oleksandr Navozenko; Juozas V Grazulevicius

doi:10.1039/d4tc04802d

Title	The effect of bipolar charge transport of derivatives of 1-phenyl-1H-benzo[d]imidazole with horizontal molecular orientation on the performance of OLEDs based on thermally activated delayed fluorescence or phosphorescence /
Authors	Macionis, Simas ; Rashid, Ehsan Ullah ; Simokaitiene, Jurate ; Butkute, Rita ; Bezvikonnyi, Oleksandr ; Volyniuk, Dmytro ; Gudeika, Dalius ; Chiu, Tien-Lung ; Lee, Jiun-Haw ; Su, Zi-Wen ; Chen, Chia-Hsun ; Budreckiene, Ruta ; Stanitska, Mariia ; Navozenko, Oleksandr ; Grazulevicius, Juozas V
DOI	10.1039/d4tc04802d
Full Text
Is Part of	Journal of materials chemistry C.. Cambridge : Royal Society of Chemistry. 2025, Early access, p. 1-11.. ISSN 2050-7534. eISSN 2050-7526
Abstract [eng]	The synthesis and properties of two derivatives of 1-phenyl-1H-benzo[d]imidazole with differing numbers of tert-butylcarbazole electron-donating moieties are reported. The compounds exhibit high thermal stability, with 5% weight loss temperatures exceeding 341 °C and glass transition temperatures of over 149 °C. They display moderate triplet energies of 2.63 and 2.66 eV. The synthesized compounds were employed as host materials in phosphorescence and TADF-based organic light-emitting diodes (OLEDs). An investigation of the angle-dependent emission intensity of light-emitting layers containing the phosphorescent emitter Ir(ppy)2(acac) doped into the examined compounds revealed a notably high internal outcoupling efficiency in OLEDs, exceeding 30%. This efficiency is attributed to the significant horizontal molecular orientation factor, reaching up to 87%. Based on the characterization of the hosting properties of 1-phenyl-1H-benzo[d]imidazole derivatives, the most significant influence on device performance is attributed to their charge-transporting properties. An OLED with the phosphorescent emitter Ir(ppy)2(acac) and a host material exhibiting bipolar charge transport demonstrated an external quantum efficiency of 13%. Additionally, the picric acid sensitivity of one of the compounds was examined. Triplet-facilitated emission was completely quenched upon the addition of a nitroaromatic explosive as a guest in a film.
Published	Cambridge : Royal Society of Chemistry
Type	Journal article
Language	English
Publication date	2025
CC license

„The effect of bipolar charge transport of derivatives of 1-phenyl-1H-benzo[d]imidazole with horizontal molecular orientation on the performance of OLEDs based on thermally activated delayed fluorescence or phosphorescence /“