1,3,4-oxadiazole-based deep-blue thermally activated delayed fluorescence emitters for organic light emitting diodes

Zhaoning Li; Wenbo Li; Changmin Keum; Emily Archer; Baomin Zhao; Alexandra Martha Zoya Slawin; Wei Huang; Malte Christian Gather; Ifor David William Samuel; Eli Zysman-Colman

doi:10.1021/acs.jpcc.9b08479

1,3,4-oxadiazole-based deep-blue thermally activated delayed fluorescence emitters for organic light emitting diodes

Zhaoning Li
, Wenbo Li
, Changmin Keum
, Emily Archer
, Baomin Zhao
, Alexandra Martha Zoya Slawin
, Wei Huang
, Malte Christian Gather
, Ifor David William Samuel
, Eli Zysman-Colman

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

Abstract

A series of four 1,3,4-oxadiazole-based thermally activated delayed fluorescence (TADF) derivatives are reported as emitters for organic light emitting diodes (OLEDs). As a function of the nature of the substituent on the weak 1,3,4-oxadiazole acceptor their emission color could be tuned from green-blue to blue. The highly twisted conformation between carbazoles and oxadiazoles results in effective separation of the HOMO and the LUMO resulting in a small singlet-triplet splitting. The corresponding singlet-triplet energy gaps (∆E_ST) range from 0.22 to 0.28 eV resulting in an efficient reverse intersystem crossing (RISC) process and moderate to high photoluminescence quantum yields (Φ_PL), ranging from 35 to 70% in a DPEPO matrix. Organic light-emitting diodes (OLEDs) based on i-2CzdOXD4CF3Ph achieve maximum external quantum efficiency (EQE_max) of up to 12.3% with a sky-blue emission at CIE of (0.18, 0.28) while the device based on i-2CzdOXDMe shows blue emission at CIE of (0.17, 0.17) with a maximum EQE of 11.8%.

Original language	English
Pages (from-to)	24772-24785
Journal	Journal of Physical Chemistry
Volume	123
Issue number	40
Early online date	16 Sept 2019
DOIs	https://doi.org/10.1021/acs.jpcc.9b08479
Publication status	Published - 10 Oct 2019

Keywords

Oxadiazole
TADF
OLED
Orientation
Transition dipole
Blue emitter

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Copyright © 2019 American Chemical Society. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the author created accepted manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1021/acs.jpcc.9b08479
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Chemistry EPSRC-JSPS: EPSRC-JSPS Core-to-Core Grant Application
Zysman-Colman, E. (PI)
1/08/18 → 31/01/24
Project: Standard
TADF Emitters for OLEDs - Eli Zysman: TADF Emitters for OLEDs
Zysman-Colman, E. (PI)
EPSRC
1/03/17 → 31/03/21
Project: Standard
TADF Emitters for OLEDs - Ifor Samuel: TADF Emitters for OLEDs
Samuel, I. (PI)
EPSRC
1/03/17 → 28/02/20
Project: Standard

New Thermally Activated Delayed Fluorescence Emitters and Room-Temperature Organic Long-Persistent Luminescence (thesis data)
Li, W. (Creator) & Samuel, I. D. W. (Supervisor), University of St Andrews, 23 Jan 2024
DOI: 10.17630/24c82e40-099d-4bbd-9a3d-6f76a1c7593c
Dataset: Thesis dataset

File
1,3,4-Oxadiazole-based Deep-blue Thermally Activated Delayed Fluorescence Emitters for Organic Light Emitting Diodes (dataset)
Li, Z. (Creator), Li, W. (Creator), Keum, C. (Creator), Archer, E. (Creator), Zhao, B. (Creator), Slawin, A. M. Z. (Creator), Huang, W. (Creator), Gather, M. C. (Creator), Samuel, I. D. W. (Creator) & Zysman-Colman, E. (Creator), University of St Andrews, 2019
DOI: 10.17630/6f373a42-75cf-438b-bd90-6e0a429142cc
Dataset

File

New thermally activated delayed fluorescence emitters and room-temperature organic long-persistent luminescence
Li, W. (Author), Samuel, I. D. W. (Supervisor), 28 Jun 2021
Student thesis: Doctoral Thesis (PhD)

Cite this

@article{e8e65a4e6cc74cf29586168fe1b49749,

title = "1,3,4-oxadiazole-based deep-blue thermally activated delayed fluorescence emitters for organic light emitting diodes",

abstract = "A series of four 1,3,4-oxadiazole-based thermally activated delayed fluorescence (TADF) derivatives are reported as emitters for organic light emitting diodes (OLEDs). As a function of the nature of the substituent on the weak 1,3,4-oxadiazole acceptor their emission color could be tuned from green-blue to blue. The highly twisted conformation between carbazoles and oxadiazoles results in effective separation of the HOMO and the LUMO resulting in a small singlet-triplet splitting. The corresponding singlet-triplet energy gaps (∆EST) range from 0.22 to 0.28 eV resulting in an efficient reverse intersystem crossing (RISC) process and moderate to high photoluminescence quantum yields (ΦPL), ranging from 35 to 70\% in a DPEPO matrix. Organic light-emitting diodes (OLEDs) based on i-2CzdOXD4CF3Ph achieve maximum external quantum efficiency (EQEmax) of up to 12.3\% with a sky-blue emission at CIE of (0.18, 0.28) while the device based on i-2CzdOXDMe shows blue emission at CIE of (0.17, 0.17) with a maximum EQE of 11.8\%.",

keywords = "Oxadiazole, TADF, OLED, Orientation, Transition dipole, Blue emitter",

author = "Zhaoning Li and Wenbo Li and Changmin Keum and Emily Archer and Baomin Zhao and Slawin, \{Alexandra Martha Zoya\} and Wei Huang and Gather, \{Malte Christian\} and Samuel, \{Ifor David William\} and Eli Zysman-Colman",

note = "We are grateful to the EPSRC for financial support (grants EP/P010482/1, EP/J01771X, EP/J00916 and EP/R035164/1). We gratefully acknowledge funding through the EPSRC NSF- CBET lead agency agreement (EP/R010595/1, 1706207) and a Leverhulme Trust Research Grant (RPG-2017-231). We thank the EPSRC UK National Mass Spectrometry Facility at Swansea University for analytical services. Z.L. and W. L. thank the China Scholarship Council (grant numbers 201703780004 and 201708060003)",

year = "2019",

month = oct,

day = "10",

doi = "10.1021/acs.jpcc.9b08479",

language = "English",

volume = "123",

pages = "24772--24785",

journal = "Journal of Physical Chemistry",

issn = "0022-3654",

publisher = "American Chemical Society (ACS)",

number = "40",

}

TY - JOUR

T1 - 1,3,4-oxadiazole-based deep-blue thermally activated delayed fluorescence emitters for organic light emitting diodes

AU - Li, Zhaoning

AU - Li, Wenbo

AU - Keum, Changmin

AU - Archer, Emily

AU - Zhao, Baomin

AU - Slawin, Alexandra Martha Zoya

AU - Huang, Wei

AU - Gather, Malte Christian

AU - Samuel, Ifor David William

AU - Zysman-Colman, Eli

N1 - We are grateful to the EPSRC for financial support (grants EP/P010482/1, EP/J01771X, EP/J00916 and EP/R035164/1). We gratefully acknowledge funding through the EPSRC NSF- CBET lead agency agreement (EP/R010595/1, 1706207) and a Leverhulme Trust Research Grant (RPG-2017-231). We thank the EPSRC UK National Mass Spectrometry Facility at Swansea University for analytical services. Z.L. and W. L. thank the China Scholarship Council (grant numbers 201703780004 and 201708060003)

PY - 2019/10/10

Y1 - 2019/10/10

N2 - A series of four 1,3,4-oxadiazole-based thermally activated delayed fluorescence (TADF) derivatives are reported as emitters for organic light emitting diodes (OLEDs). As a function of the nature of the substituent on the weak 1,3,4-oxadiazole acceptor their emission color could be tuned from green-blue to blue. The highly twisted conformation between carbazoles and oxadiazoles results in effective separation of the HOMO and the LUMO resulting in a small singlet-triplet splitting. The corresponding singlet-triplet energy gaps (∆EST) range from 0.22 to 0.28 eV resulting in an efficient reverse intersystem crossing (RISC) process and moderate to high photoluminescence quantum yields (ΦPL), ranging from 35 to 70% in a DPEPO matrix. Organic light-emitting diodes (OLEDs) based on i-2CzdOXD4CF3Ph achieve maximum external quantum efficiency (EQEmax) of up to 12.3% with a sky-blue emission at CIE of (0.18, 0.28) while the device based on i-2CzdOXDMe shows blue emission at CIE of (0.17, 0.17) with a maximum EQE of 11.8%.

AB - A series of four 1,3,4-oxadiazole-based thermally activated delayed fluorescence (TADF) derivatives are reported as emitters for organic light emitting diodes (OLEDs). As a function of the nature of the substituent on the weak 1,3,4-oxadiazole acceptor their emission color could be tuned from green-blue to blue. The highly twisted conformation between carbazoles and oxadiazoles results in effective separation of the HOMO and the LUMO resulting in a small singlet-triplet splitting. The corresponding singlet-triplet energy gaps (∆EST) range from 0.22 to 0.28 eV resulting in an efficient reverse intersystem crossing (RISC) process and moderate to high photoluminescence quantum yields (ΦPL), ranging from 35 to 70% in a DPEPO matrix. Organic light-emitting diodes (OLEDs) based on i-2CzdOXD4CF3Ph achieve maximum external quantum efficiency (EQEmax) of up to 12.3% with a sky-blue emission at CIE of (0.18, 0.28) while the device based on i-2CzdOXDMe shows blue emission at CIE of (0.17, 0.17) with a maximum EQE of 11.8%.

KW - Oxadiazole

KW - TADF

KW - OLED

KW - Orientation

KW - Transition dipole

KW - Blue emitter

U2 - 10.1021/acs.jpcc.9b08479

DO - 10.1021/acs.jpcc.9b08479

M3 - Article

SN - 0022-3654

VL - 123

SP - 24772

EP - 24785

JO - Journal of Physical Chemistry

JF - Journal of Physical Chemistry

IS - 40

ER -

1,3,4-oxadiazole-based deep-blue thermally activated delayed fluorescence emitters for organic light emitting diodes

Abstract

Keywords

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Projects

Chemistry EPSRC-JSPS: EPSRC-JSPS Core-to-Core Grant Application

TADF Emitters for OLEDs - Eli Zysman: TADF Emitters for OLEDs

TADF Emitters for OLEDs - Ifor Samuel: TADF Emitters for OLEDs

Datasets

New Thermally Activated Delayed Fluorescence Emitters and Room-Temperature Organic Long-Persistent Luminescence (thesis data)

1,3,4-Oxadiazole-based Deep-blue Thermally Activated Delayed Fluorescence Emitters for Organic Light Emitting Diodes (dataset)

Student theses

New thermally activated delayed fluorescence emitters and room-temperature organic long-persistent luminescence

Cite this