Thermally activated delayed fluorescence carbazole-triazine dendrimer with bulky substituents

Hiroki Ikebe; Kohei Nakao; Eri Hisamura; Minori Furukori; Yasuo Nakayama; Takuya Hosokai; Minlang Yang; Guanting Liu; Takuma Yasuda; Ken Albrecht

doi:10.1002/agt2.405

Thermally activated delayed fluorescence carbazole-triazine dendrimer with bulky substituents

Hiroki Ikebe, Kohei Nakao, Eri Hisamura, Minori Furukori, Yasuo Nakayama, Takuya Hosokai, Minlang Yang, Guanting Liu, Takuma Yasuda, Ken Albrecht

Department of Pure and Applied Chemistry

Research output: Contribution to journal › Article › peer-review

16 Citations (Scopus)

Abstract

Carbazole-triazine dendrimers with a bulky terminal substituent were synthesized, and the thermally activated delayed fluorescence (TADF) property was investigated. Compared to unsubstituted carbazole dendrimers, dendrimers with bulky terminal substituents showed comparable to better photoluminescence quantum yields (PLQY) in neat films. Phenylfluorene (PF)-substituted dendrimers showed the highest PLQY of 81%, a small ΔE_st of 0.06 eV, and the fastest reverse intersystem crossing (RISC) rate of ∼1 × 10⁵ s⁻¹ compared to other dendrimers. Phosphorescence measurements of dendrimers and dendrons (fragments) indicate that the close proximity of the triplet energy of phenylfluorene-substituted carbazole dendrons (³LE) to that of phenylfluorene-substituted dendrimers (¹CT, ³CT) contributes to RISC promotion and improves TADF efficiency. Terminal modification fine-tunes the energy level and suppresses intermolecular interactions, and this study provides a guideline for designing efficient solution-processable and non-doped TADF materials.

Original language	English
Article number	e405
Journal	Aggregate
Volume	5
Issue number	1
DOIs	https://doi.org/10.1002/agt2.405
Publication status	Published - Feb 2024

Keywords

OLED
TADF
dendrimer

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10.1002/agt2.405

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title = "Thermally activated delayed fluorescence carbazole-triazine dendrimer with bulky substituents",

abstract = "Carbazole-triazine dendrimers with a bulky terminal substituent were synthesized, and the thermally activated delayed fluorescence (TADF) property was investigated. Compared to unsubstituted carbazole dendrimers, dendrimers with bulky terminal substituents showed comparable to better photoluminescence quantum yields (PLQY) in neat films. Phenylfluorene (PF)-substituted dendrimers showed the highest PLQY of 81%, a small ΔEst of 0.06 eV, and the fastest reverse intersystem crossing (RISC) rate of ∼1 × 105 s−1 compared to other dendrimers. Phosphorescence measurements of dendrimers and dendrons (fragments) indicate that the close proximity of the triplet energy of phenylfluorene-substituted carbazole dendrons (3LE) to that of phenylfluorene-substituted dendrimers (1CT, 3CT) contributes to RISC promotion and improves TADF efficiency. Terminal modification fine-tunes the energy level and suppresses intermolecular interactions, and this study provides a guideline for designing efficient solution-processable and non-doped TADF materials.",

keywords = "OLED, TADF, dendrimer",

author = "Hiroki Ikebe and Kohei Nakao and Eri Hisamura and Minori Furukori and Yasuo Nakayama and Takuya Hosokai and Minlang Yang and Guanting Liu and Takuma Yasuda and Ken Albrecht",

note = "Publisher Copyright: {\textcopyright} 2023 The Authors. Aggregate published by SCUT, AIEI, and John Wiley & Sons Australia, Ltd.",

year = "2024",

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doi = "10.1002/agt2.405",

language = "English",

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T1 - Thermally activated delayed fluorescence carbazole-triazine dendrimer with bulky substituents

AU - Ikebe, Hiroki

AU - Nakao, Kohei

AU - Hisamura, Eri

AU - Furukori, Minori

AU - Nakayama, Yasuo

AU - Hosokai, Takuya

AU - Yang, Minlang

AU - Liu, Guanting

AU - Yasuda, Takuma

AU - Albrecht, Ken

PY - 2024/2

Y1 - 2024/2

N2 - Carbazole-triazine dendrimers with a bulky terminal substituent were synthesized, and the thermally activated delayed fluorescence (TADF) property was investigated. Compared to unsubstituted carbazole dendrimers, dendrimers with bulky terminal substituents showed comparable to better photoluminescence quantum yields (PLQY) in neat films. Phenylfluorene (PF)-substituted dendrimers showed the highest PLQY of 81%, a small ΔEst of 0.06 eV, and the fastest reverse intersystem crossing (RISC) rate of ∼1 × 105 s−1 compared to other dendrimers. Phosphorescence measurements of dendrimers and dendrons (fragments) indicate that the close proximity of the triplet energy of phenylfluorene-substituted carbazole dendrons (3LE) to that of phenylfluorene-substituted dendrimers (1CT, 3CT) contributes to RISC promotion and improves TADF efficiency. Terminal modification fine-tunes the energy level and suppresses intermolecular interactions, and this study provides a guideline for designing efficient solution-processable and non-doped TADF materials.

AB - Carbazole-triazine dendrimers with a bulky terminal substituent were synthesized, and the thermally activated delayed fluorescence (TADF) property was investigated. Compared to unsubstituted carbazole dendrimers, dendrimers with bulky terminal substituents showed comparable to better photoluminescence quantum yields (PLQY) in neat films. Phenylfluorene (PF)-substituted dendrimers showed the highest PLQY of 81%, a small ΔEst of 0.06 eV, and the fastest reverse intersystem crossing (RISC) rate of ∼1 × 105 s−1 compared to other dendrimers. Phosphorescence measurements of dendrimers and dendrons (fragments) indicate that the close proximity of the triplet energy of phenylfluorene-substituted carbazole dendrons (3LE) to that of phenylfluorene-substituted dendrimers (1CT, 3CT) contributes to RISC promotion and improves TADF efficiency. Terminal modification fine-tunes the energy level and suppresses intermolecular interactions, and this study provides a guideline for designing efficient solution-processable and non-doped TADF materials.

KW - OLED

KW - TADF

KW - dendrimer

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U2 - 10.1002/agt2.405

DO - 10.1002/agt2.405

M3 - Article

AN - SCOPUS:85168283413

SN - 2766-8541

VL - 5

JO - Aggregate

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IS - 1

M1 - e405

ER -

Thermally activated delayed fluorescence carbazole-triazine dendrimer with bulky substituents

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Keywords

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