Spin-Dependent Exciton Funneling to a Dendritic Fluorophore Mediated by a Thermally Activated Delayed Fluorescence Material as an Exciton-Harvesting Host

Naoya Aizawa, So Shikita, Takuma Yasuda

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Thermally activated delayed fluorescence (TADF) materials generate energetically equivalent spin-singlet and spin-triplet excited states. In the presence of an energy acceptor, each excited state undergoes energy transfer on different length scales. However, the lack of quantitative understanding of the length dependence of the excited energy-transfer processes hampers the rational design of molecular systems that control exciton transport in organic light-emitting diodes (OLEDs) using TADF. We herein utilize a dendritic fluorophore G1, which consists of an anthracene-based fluorescent core encapsulated by four insulating tris(4-tert-butylphenyl)methyl groups as an energy acceptor. By combining transient photoluminescence measurements and kinetic modeling, we demonstrate the spin-dependent energy transfer in a binary host-guest system composed of a TADF material as the exciton-harvesting host and G1 as the guest fluorophore. The encapsulated structure with the dendritic shell effectively inhibits triplet excitons on the TADF host from funneling to the fluorescent core, thus allowing efficient reverse intersystem crossing and singlet energy transfer. The utilization of G1 in solution-processed OLEDs leads to a maximum external electroluminescence quantum efficiency as high as 5.2%, which is equivalent to an enhancement by a factor of 1.6 over the corresponding nondendritic fluorophore.

Original languageEnglish
Pages (from-to)7014-7022
Number of pages9
JournalChemistry of Materials
Volume29
Issue number16
DOIs
Publication statusPublished - Aug 22 2017

Fingerprint

Fluorophores
Excitons
Energy transfer
Fluorescence
Organic light emitting diodes (OLED)
Excited states
Anthracene
Electroluminescence
Quantum efficiency
Photoluminescence
Control systems
Kinetics
LDS 751

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

Cite this

Spin-Dependent Exciton Funneling to a Dendritic Fluorophore Mediated by a Thermally Activated Delayed Fluorescence Material as an Exciton-Harvesting Host. / Aizawa, Naoya; Shikita, So; Yasuda, Takuma.

In: Chemistry of Materials, Vol. 29, No. 16, 22.08.2017, p. 7014-7022.

Research output: Contribution to journalArticle

@article{5338f907f9974e7198fc15abd1dd165d,
title = "Spin-Dependent Exciton Funneling to a Dendritic Fluorophore Mediated by a Thermally Activated Delayed Fluorescence Material as an Exciton-Harvesting Host",
abstract = "Thermally activated delayed fluorescence (TADF) materials generate energetically equivalent spin-singlet and spin-triplet excited states. In the presence of an energy acceptor, each excited state undergoes energy transfer on different length scales. However, the lack of quantitative understanding of the length dependence of the excited energy-transfer processes hampers the rational design of molecular systems that control exciton transport in organic light-emitting diodes (OLEDs) using TADF. We herein utilize a dendritic fluorophore G1, which consists of an anthracene-based fluorescent core encapsulated by four insulating tris(4-tert-butylphenyl)methyl groups as an energy acceptor. By combining transient photoluminescence measurements and kinetic modeling, we demonstrate the spin-dependent energy transfer in a binary host-guest system composed of a TADF material as the exciton-harvesting host and G1 as the guest fluorophore. The encapsulated structure with the dendritic shell effectively inhibits triplet excitons on the TADF host from funneling to the fluorescent core, thus allowing efficient reverse intersystem crossing and singlet energy transfer. The utilization of G1 in solution-processed OLEDs leads to a maximum external electroluminescence quantum efficiency as high as 5.2{\%}, which is equivalent to an enhancement by a factor of 1.6 over the corresponding nondendritic fluorophore.",
author = "Naoya Aizawa and So Shikita and Takuma Yasuda",
year = "2017",
month = "8",
day = "22",
doi = "10.1021/acs.chemmater.7b02606",
language = "English",
volume = "29",
pages = "7014--7022",
journal = "Chemistry of Materials",
issn = "0897-4756",
publisher = "American Chemical Society",
number = "16",

}

TY - JOUR

T1 - Spin-Dependent Exciton Funneling to a Dendritic Fluorophore Mediated by a Thermally Activated Delayed Fluorescence Material as an Exciton-Harvesting Host

AU - Aizawa, Naoya

AU - Shikita, So

AU - Yasuda, Takuma

PY - 2017/8/22

Y1 - 2017/8/22

N2 - Thermally activated delayed fluorescence (TADF) materials generate energetically equivalent spin-singlet and spin-triplet excited states. In the presence of an energy acceptor, each excited state undergoes energy transfer on different length scales. However, the lack of quantitative understanding of the length dependence of the excited energy-transfer processes hampers the rational design of molecular systems that control exciton transport in organic light-emitting diodes (OLEDs) using TADF. We herein utilize a dendritic fluorophore G1, which consists of an anthracene-based fluorescent core encapsulated by four insulating tris(4-tert-butylphenyl)methyl groups as an energy acceptor. By combining transient photoluminescence measurements and kinetic modeling, we demonstrate the spin-dependent energy transfer in a binary host-guest system composed of a TADF material as the exciton-harvesting host and G1 as the guest fluorophore. The encapsulated structure with the dendritic shell effectively inhibits triplet excitons on the TADF host from funneling to the fluorescent core, thus allowing efficient reverse intersystem crossing and singlet energy transfer. The utilization of G1 in solution-processed OLEDs leads to a maximum external electroluminescence quantum efficiency as high as 5.2%, which is equivalent to an enhancement by a factor of 1.6 over the corresponding nondendritic fluorophore.

AB - Thermally activated delayed fluorescence (TADF) materials generate energetically equivalent spin-singlet and spin-triplet excited states. In the presence of an energy acceptor, each excited state undergoes energy transfer on different length scales. However, the lack of quantitative understanding of the length dependence of the excited energy-transfer processes hampers the rational design of molecular systems that control exciton transport in organic light-emitting diodes (OLEDs) using TADF. We herein utilize a dendritic fluorophore G1, which consists of an anthracene-based fluorescent core encapsulated by four insulating tris(4-tert-butylphenyl)methyl groups as an energy acceptor. By combining transient photoluminescence measurements and kinetic modeling, we demonstrate the spin-dependent energy transfer in a binary host-guest system composed of a TADF material as the exciton-harvesting host and G1 as the guest fluorophore. The encapsulated structure with the dendritic shell effectively inhibits triplet excitons on the TADF host from funneling to the fluorescent core, thus allowing efficient reverse intersystem crossing and singlet energy transfer. The utilization of G1 in solution-processed OLEDs leads to a maximum external electroluminescence quantum efficiency as high as 5.2%, which is equivalent to an enhancement by a factor of 1.6 over the corresponding nondendritic fluorophore.

UR - http://www.scopus.com/inward/record.url?scp=85027992182&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85027992182&partnerID=8YFLogxK

U2 - 10.1021/acs.chemmater.7b02606

DO - 10.1021/acs.chemmater.7b02606

M3 - Article

AN - SCOPUS:85027992182

VL - 29

SP - 7014

EP - 7022

JO - Chemistry of Materials

JF - Chemistry of Materials

SN - 0897-4756

IS - 16

ER -