Power Efficiency Enhancement of Organic Light-Emitting Diodes Due to the Favorable Horizontal Orientation of a Naphthyridine-Based Thermally Activated Delayed Fluorescence Luminophore

被引：4

作者：

Keruckiene, Rasa ^{[3
]}

Vijaikis, Eimantas ^{[3
]}

Chen, Chia-Hsun ^{[1
]}

Lin, Bo-Yen ^{[4
]}

Huang, Jing-Xiang ^{[1
]}

Chu, Chun-Chieh ^{[1
]}

Dzeng, YiChung ^{[5
]}

Chen, Chi ^{[5
]}

Lee, Jiun-Haw ^{[1
]}

Chiu, Tien-Lung ^{[2
]}

Macionis, Simas ^{[3
]}

Keruckas, Jonas ^{[3
]}

Butkute, Rita ^{[3
]}

Grazulevicius, Juozas Vidas ^{[3
]}

机构：

[1] Natl Taiwan Univ, Grad Inst Photon & Optoelect, Dept Elect Engn, Mat Sci & Engn & Phys, Taipei 10617, Taiwan

[2] Yuan Ze Univ, Dept Elect Engn, Chungli 32003, Taiwan

[3] Kaunas Univ Technol, Dept Polymer Chem & Technol, LT-50254 Kaunas, Lithuania

[4] Natl Dong Hwa Univ, Dept Optoelect Engn, Hualien 974301, Taiwan

[5] Acad Sinica, Res Ctr Appl Sci, Taipei 11529, Taiwan

来源：

ACS APPLIED ELECTRONIC MATERIALS | 2023年 / 5卷 / 02期

关键词：

naphthyridine; angle-dependent photoluminescence; grazing-incidence small-angle X-ray scattering; thermally activated delayed fluorescence; molecular orientation; OLED; EMISSION; EMITTERS;

D O I：

10.1021/acsaelm.2c01529

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

Four emitters based on the naphthyridine acceptor moiety and various donor units exhibiting thermally activated delayed fluorescence (TADF) were designed and synthesized. The emitters exhibited excellent TADF properties with a small Delta EST and a high photoluminescence quantum yield. A green TADF organic light-emitting diode based on 10-(4-(1,8-naphthyridin-2-yl)phenyl)-10H-phenothiazine exhibited a maximum external quantum efficiency of 16.4% with Commission Internationale de L'eclairage coordinates of (0.368, 0.569) as well as a high current and power efficiency of 58.6 cd/A and 57.1 lm/W, respectively. The supreme power efficiency is a record-high value among the reported values of devices with naphthyridine-based emitters. This results from its high photoluminescence quantum yield, efficient TADF, and horizontal molecular orientation. The molecular orientations of the films of the host and the host doped with the naphthyridine emitter were explored by angle-dependent photoluminescence and grazing-incidence small-angle X-ray scattering (GIWAXS). The orientation order parameters (Theta(ADPL)) were found to be 0.37, 0.45, 0.62, and 0.74 for the naphthyridine dopants with dimethylacridan, carbazole, phenoxazine, and phenothiazine donor moieties, respectively. These results were also proven by GIWAXS measurement. The derivative of naphthyridine and phenothiazine was shown to be more flexible to align with the host and to show the favorable horizontal molecular orientation and crystalline domain size, benefiting the outcoupling efficiency and contributing to the device efficiency.

引用

页码：1013 / 1023

页数：11

共 36 条

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