TY - JOUR
T1 - 5H-Benzo[d]Benzo[4,5]Imidazo[2,1-b][1,3]Thiazine as a Novel Electron-Acceptor Cored High Triplet Energy Bipolar Host Material for Efficient Solution-Processable Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes
AU - Godumala, Mallesham
AU - Yoon, Jiwon
AU - Park, Seo Yeon
AU - Lee, Chiho
AU - Kim, Youngseo
AU - Jeong, Ji Eun
AU - Park, Sungnam
AU - Woo, Han Young
AU - Cho, Min Ju
AU - Choi, Dong Hoon
N1 - Funding Information:
The authors acknowledge the financial support from the National Research Foundation of Korea (NRF2019R1A2C2002647, NRF2019R1A6A1A11044070) and also thanks to the Korea Basic Science Institute in Seoul for allowing us to use MALDI-TOF MS instrument.
Funding Information:
The authors acknowledge the financial support from the National Research Foundation of Korea (NRF2019R1A2C2002647, NRF2019R1A6A1A11044070) and also thanks to the Korea Basic Science Institute in Seoul for allowing us to use MALDI-TOF MS instrument. Funding. The authors declare that this study received funding from LG Display Co. Limited (2019). The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication.
Funding Information:
The authors declare that this study received funding from LG Display Co. Limited (2019). The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication.
Publisher Copyright:
© Copyright © 2020 Godumala, Yoon, Park, Lee, Kim, Jeong, Park, Woo, Cho and Choi.
PY - 2020/2/7
Y1 - 2020/2/7
N2 - Organic entities that can transport electrons are seldom available to develop adequate bipolar host materials applicable for solution-processable thermally activated delayed fluorescence (TADF)-organic light-emitting diodes (OLEDs). Therefore, the introduction of new electron-affine entities that plausibly demonstrate high triplet energy (ET) is of urgent need. In this contribution, we introduced benzimidazo[1,2-a][3,1]benzothiazine (BBIT) as a novel electron-affine entity and developed two new bipolar host materials, CzBBIT and 2CzBBIT. Both host materials exhibit high ET of 3.0 eV, superior thermal robustness with the thermal decomposition temperature of up to 392°C, a glass transition temperature of up to 161°C, and high solubility in common organic solvents. Consequently, the solution-processable OLEDs fabricated using a recognized IAcTr-out as the green TADF emitter doped into CzBBIT as the host, realized a maximum external quantum efficiency (EQE) of 23.3%, while the 2CzBBIT:IAcTr-out blend film-based device displayed an EQE of 18.7%. These outcomes corroborated that this work could shed light on the scientific community on the design of new electron-affine entities to establish the effective use of bipolar host materials toward proficient solution-processable TADF-OLEDs.
AB - Organic entities that can transport electrons are seldom available to develop adequate bipolar host materials applicable for solution-processable thermally activated delayed fluorescence (TADF)-organic light-emitting diodes (OLEDs). Therefore, the introduction of new electron-affine entities that plausibly demonstrate high triplet energy (ET) is of urgent need. In this contribution, we introduced benzimidazo[1,2-a][3,1]benzothiazine (BBIT) as a novel electron-affine entity and developed two new bipolar host materials, CzBBIT and 2CzBBIT. Both host materials exhibit high ET of 3.0 eV, superior thermal robustness with the thermal decomposition temperature of up to 392°C, a glass transition temperature of up to 161°C, and high solubility in common organic solvents. Consequently, the solution-processable OLEDs fabricated using a recognized IAcTr-out as the green TADF emitter doped into CzBBIT as the host, realized a maximum external quantum efficiency (EQE) of 23.3%, while the 2CzBBIT:IAcTr-out blend film-based device displayed an EQE of 18.7%. These outcomes corroborated that this work could shed light on the scientific community on the design of new electron-affine entities to establish the effective use of bipolar host materials toward proficient solution-processable TADF-OLEDs.
KW - bipolar hosts
KW - new electron-acceptor core
KW - organic light emitting diodes
KW - solution process
KW - thermally activated delayed fluorescence
UR - http://www.scopus.com/inward/record.url?scp=85079780085&partnerID=8YFLogxK
U2 - 10.3389/fchem.2020.00061
DO - 10.3389/fchem.2020.00061
M3 - Article
AN - SCOPUS:85079780085
SN - 2296-2646
VL - 8
JO - Frontiers in Chemistry
JF - Frontiers in Chemistry
M1 - 61
ER -