Chromenopyrazole-Based Bipolar Blue Host Materials for Highly Efficient Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes

Mallesham Godumala, Suna Choi, Seo Yeon Park, Min Ju Cho, Hyung Jong Kim, Dae Hyun Ahn, Ji Su Moon, Jang Hyuk Kwon, Dong Hoon Choi

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

New electron-acceptor cores are necessary for developing highly efficient bipolar hosts, particularly for blue thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs). Herein, chromenopyrazole (CP) was used for the first time as an electron-acceptor core to design and synthesize two novel blue bipolar hosts, viz., 8-(9H-carbazol-9-yl)-3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-one (CzCP) and 8-(9H-[3,9′-bicarbazol]-9-yl)-3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-one (2CzCP). The influence of donor strength on the photophysical, electrochemical, and electroluminescent performances was systematically investigated. CzCP and 2CzCP both maintain high triplet energy (∼3.0 eV), appropriate highest occupied and lowest unoccupied energy levels (HOMO/LUMO), and bipolar nature. Consequently, OLEDs containing CzCP as a host in the emissive layer exhibited state-of-the-art performance with external quantum efficiency of 27.9% and CIE color coordinates of (0.15, 0.21), thus achieving excellent performance among all reported blue host materials in TADF-OLEDs. This work highlights the importance of the CP unit in developing new host materials and paves the way for the realization of high-efficiency blue TADF-OLEDs.

Original languageEnglish
Pages (from-to)5005-5012
Number of pages8
JournalChemistry of Materials
Volume30
Issue number15
DOIs
Publication statusPublished - 2018 Aug 14

Fingerprint

Organic light emitting diodes (OLED)
Fluorescence
Electrons
Quantum efficiency
Electron energy levels
Color

ASJC Scopus subject areas

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

Cite this

Chromenopyrazole-Based Bipolar Blue Host Materials for Highly Efficient Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes. / Godumala, Mallesham; Choi, Suna; Park, Seo Yeon; Cho, Min Ju; Kim, Hyung Jong; Ahn, Dae Hyun; Moon, Ji Su; Kwon, Jang Hyuk; Choi, Dong Hoon.

In: Chemistry of Materials, Vol. 30, No. 15, 14.08.2018, p. 5005-5012.

Research output: Contribution to journalArticle

Godumala, Mallesham ; Choi, Suna ; Park, Seo Yeon ; Cho, Min Ju ; Kim, Hyung Jong ; Ahn, Dae Hyun ; Moon, Ji Su ; Kwon, Jang Hyuk ; Choi, Dong Hoon. / Chromenopyrazole-Based Bipolar Blue Host Materials for Highly Efficient Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes. In: Chemistry of Materials. 2018 ; Vol. 30, No. 15. pp. 5005-5012.
@article{b9eac421799342939e3c844705cb9d24,
title = "Chromenopyrazole-Based Bipolar Blue Host Materials for Highly Efficient Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes",
abstract = "New electron-acceptor cores are necessary for developing highly efficient bipolar hosts, particularly for blue thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs). Herein, chromenopyrazole (CP) was used for the first time as an electron-acceptor core to design and synthesize two novel blue bipolar hosts, viz., 8-(9H-carbazol-9-yl)-3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-one (CzCP) and 8-(9H-[3,9′-bicarbazol]-9-yl)-3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-one (2CzCP). The influence of donor strength on the photophysical, electrochemical, and electroluminescent performances was systematically investigated. CzCP and 2CzCP both maintain high triplet energy (∼3.0 eV), appropriate highest occupied and lowest unoccupied energy levels (HOMO/LUMO), and bipolar nature. Consequently, OLEDs containing CzCP as a host in the emissive layer exhibited state-of-the-art performance with external quantum efficiency of 27.9{\%} and CIE color coordinates of (0.15, 0.21), thus achieving excellent performance among all reported blue host materials in TADF-OLEDs. This work highlights the importance of the CP unit in developing new host materials and paves the way for the realization of high-efficiency blue TADF-OLEDs.",
author = "Mallesham Godumala and Suna Choi and Park, {Seo Yeon} and Cho, {Min Ju} and Kim, {Hyung Jong} and Ahn, {Dae Hyun} and Moon, {Ji Su} and Kwon, {Jang Hyuk} and Choi, {Dong Hoon}",
year = "2018",
month = "8",
day = "14",
doi = "10.1021/acs.chemmater.8b01207",
language = "English",
volume = "30",
pages = "5005--5012",
journal = "Chemistry of Materials",
issn = "0897-4756",
publisher = "American Chemical Society",
number = "15",

}

TY - JOUR

T1 - Chromenopyrazole-Based Bipolar Blue Host Materials for Highly Efficient Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes

AU - Godumala, Mallesham

AU - Choi, Suna

AU - Park, Seo Yeon

AU - Cho, Min Ju

AU - Kim, Hyung Jong

AU - Ahn, Dae Hyun

AU - Moon, Ji Su

AU - Kwon, Jang Hyuk

AU - Choi, Dong Hoon

PY - 2018/8/14

Y1 - 2018/8/14

N2 - New electron-acceptor cores are necessary for developing highly efficient bipolar hosts, particularly for blue thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs). Herein, chromenopyrazole (CP) was used for the first time as an electron-acceptor core to design and synthesize two novel blue bipolar hosts, viz., 8-(9H-carbazol-9-yl)-3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-one (CzCP) and 8-(9H-[3,9′-bicarbazol]-9-yl)-3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-one (2CzCP). The influence of donor strength on the photophysical, electrochemical, and electroluminescent performances was systematically investigated. CzCP and 2CzCP both maintain high triplet energy (∼3.0 eV), appropriate highest occupied and lowest unoccupied energy levels (HOMO/LUMO), and bipolar nature. Consequently, OLEDs containing CzCP as a host in the emissive layer exhibited state-of-the-art performance with external quantum efficiency of 27.9% and CIE color coordinates of (0.15, 0.21), thus achieving excellent performance among all reported blue host materials in TADF-OLEDs. This work highlights the importance of the CP unit in developing new host materials and paves the way for the realization of high-efficiency blue TADF-OLEDs.

AB - New electron-acceptor cores are necessary for developing highly efficient bipolar hosts, particularly for blue thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs). Herein, chromenopyrazole (CP) was used for the first time as an electron-acceptor core to design and synthesize two novel blue bipolar hosts, viz., 8-(9H-carbazol-9-yl)-3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-one (CzCP) and 8-(9H-[3,9′-bicarbazol]-9-yl)-3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-one (2CzCP). The influence of donor strength on the photophysical, electrochemical, and electroluminescent performances was systematically investigated. CzCP and 2CzCP both maintain high triplet energy (∼3.0 eV), appropriate highest occupied and lowest unoccupied energy levels (HOMO/LUMO), and bipolar nature. Consequently, OLEDs containing CzCP as a host in the emissive layer exhibited state-of-the-art performance with external quantum efficiency of 27.9% and CIE color coordinates of (0.15, 0.21), thus achieving excellent performance among all reported blue host materials in TADF-OLEDs. This work highlights the importance of the CP unit in developing new host materials and paves the way for the realization of high-efficiency blue TADF-OLEDs.

UR - http://www.scopus.com/inward/record.url?scp=85049643448&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85049643448&partnerID=8YFLogxK

U2 - 10.1021/acs.chemmater.8b01207

DO - 10.1021/acs.chemmater.8b01207

M3 - Article

AN - SCOPUS:85049643448

VL - 30

SP - 5005

EP - 5012

JO - Chemistry of Materials

JF - Chemistry of Materials

SN - 0897-4756

IS - 15

ER -