Dye-based nanoarchitectonics for the effective bandgap and stability of blue phosphorescent organic light-emitting diodes

Abstract Blue phosphorescent organic light-emitting diodes (B-PHOLEDs) using host–guest emissive layers have been studied, where the host and guest are 2,6-bis(3-(9H-carbazol-9-yl)phenyl)pyridine (26DCzPPy) and bis[2-(4,6-difluorophenyl)pyridinato-$ C^{2} $,N](picolinato)iridium(III) (FIrPic), respe...
Ausführliche Beschreibung

Abstract Blue phosphorescent organic light-emitting diodes (B-PHOLEDs) using host–guest emissive layers have been studied, where the host and guest are 2,6-bis(3-(9H-carbazol-9-yl)phenyl)pyridine (26DCzPPy) and bis[2-(4,6-difluorophenyl)pyridinato-$ C^{2} $,N](picolinato)iridium(III) (FIrPic), respectively. For the emissive layer with dye (guest) concentration of either 3 mol% or 10 mol%, there exist both the major and minor effective bandgaps. The major effective bandgap is governed by the lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) levels of 26DCzPPy, because the host molecules form a major dynamic-favorable channel to transport charge carriers. The minor effective bandgap is governed by the LUMO and HOMO levels of FIrPic, since the guest molecules form a minor thermodynamic-favorable channel to transport charge carriers. For the emissive layer with dye concentration of 22 mol%, the effective bandgap is determined by the LUMO and HOMO levels of FIrPic, because the guest molecules form a both dynamic- and thermodynamic-favorable channel to conduct charge carriers. Although the B-PHOLED with emissive layer of 26DCzPPy:FIrPic (3 mol%) shows wider exciton formation zone than the one with emissive layer of 26DCzPPy:FIrPic (10 mol%), the latter gives higher stability than the former, mostly attributed to the shorter triplet lifetime of 26DCzPPy:FIrPic (10 mol%) than that of 26DCzPPy:FIrPic (3 mol%). Due to both the larger effective bandgap and more charge carrier traps, the emissive layer of 26DCzPPy:FIrPic (10 mol%) enlarges the exciton formation zone and thereby increases device stability than that of 26DCzPPy:FIrPic (22 mol%), despite that the former has the longer triplet lifetime than the latter. The current research provides some novel insights into the correlation of dye-based nanoarchitectonics (dye concentration) with the device performance, helpful for the commercial development of B-PHOLEDs using host–guest emissive layers. Ausführliche Beschreibung

Autor*in:	Zhao, Hailiang [verfasserIn] Li, Jiatong Sun, Weidong He, Liang Li, Xin Jia, Xueyi Qin, Dashan

Format:	E-Artikel
Sprache:	Englisch

Erschienen:	2023

Schlagwörter:	Blue phosphorescent organic light-emitting diodes Charge transport Effective bandgap Exciton formation zone Device stability

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© The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Übergeordnetes Werk:	Enthalten in: Applied physics - Berlin : Springer, 1973, 130(2023), 1 vom: 29. Dez.
Übergeordnetes Werk:	volume:130 ; year:2023 ; number:1 ; day:29 ; month:12

Links:	Volltext

DOI / URN:	10.1007/s00339-023-07225-5

Katalog-ID:	SPR054203147