Flexible diphenylsulfone versus rigid dibenzothiophene-dioxide as acceptor moieties in donor-acceptor-donor TADF emitters for highly efficient OLEDs

被引：12

作者：

Gudeika D. ^{[1
,2
]}

Lee J.H. ^{[3
]}

Lee P.-H. ^{[3
]}

Chen C.-H. ^{[3
]}

Chiu T.-L. ^{[4
]}

Baryshnikov G.V. ^{[5
,6
]}

Minaev B.F. ^{[5
]}

Ågren H. ^{[5
,7
]}

Volyniuk D. ^{[1
]}

Bezvikonnyi O. ^{[1
]}

Grazulevicius J.V. ^{[1
]}

机构：

[1] Department of Polymer Chemistry and Technology, Kaunas University of Technology, Radvilenu pl. 19, LT-50254, Kaunas

[2] Institute of Solid State Physics, University of Latvia, 8 Kengaraga St., LV-1063, Riga

[3] Graduate Institute of Photonics and Optoelectronics, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei

[4] Department of Electrical Engineering, Yuan Ze University, 135 Yuan-Tung Road, Taoyuan

[5] Division of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Stockholm

[6] Department of Chemistry and Nanomaterials Science, Bohdan Khmelnytsky National University, Cherkasy

[7] College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan

来源：

Grazulevicius, Juozas V. (juozas.grazulevicius@ktu.lt) | 1600年 / Elsevier B.V., Netherlands卷 / 83期

基金：

欧盟地平线“2020”;

关键词：

Bipolar charge transport; di-tert-butyldimethyldihydroacridine; Dibenzothiophene dioxide; Diphenylsulfone; Thermally activated delayed fluorescence;

D O I：

10.1016/j.orgel.2020.105733

中图分类号：

学科分类号：

摘要：

Flexible versus rigid molecular structures of donor-acceptor-donor type compounds are investigated with respect to efficiency of thermally activated delayed fluorescence (TADF) by theoretical and experimental approaches. Three highly efficient TADF emitters based on flexible diphenylsulfone and rigid dibenzothiophene-dioxide as acceptor units and di-tert-butyldimethyldihydroacridine as donor moiety were designed and synthesized. Despite they showed similar singlet-triplet splitting (0.01–0.02 eV) and high photoluminescence quantum yields in appropriate hosts, maximum external quantum efficiencies as different as 24.1 and 15.9/19.4% were obtained for organic light emitting devices based on these emitters with, respectively, flexible and rigid molecular structures. The high efficiency of the light-emitting compounds with the flexible molecular structure could be traced to the bi-configurational nature of the lowest singlet and triplet states resulting in higher spin-orbit coupling than for molecules with rigid structures. All derivatives showed bipolar charge transport character. High device efficiency with electron mobility of 3 × 10−5 cm2V−1s−1 and hole mobility of 1.3 × 10−4 cm2V−1s−1 at the electric field of 5 × 105 Vcm−1 was recorded for the layer of para-disubstituted diphenylsulfone with flexible molecular structure. This TADF emitter showed an excellent performance in the organic light emitting device, exhibiting a maximum current efficiency, power efficiency, and external quantum efficiency of 61.1 cdA-1, 64.0 lmW−1, and 24.1%, respectively. © 2020 Elsevier B.V.

引用

共 48 条

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