李久艳

个人信息Personal Information

教授

博士生导师

硕士生导师

性别:女

毕业院校:中科院理化所

学位:博士

所在单位:化工学院

学科:应用化学. 有机化学

办公地点:化工实验楼E202

联系方式:jiuyanli@dlut.edu.cn

电子邮箱:jiuyanli@dlut.edu.cn

扫描关注

论文成果

当前位置: 中文主页 >> 科学研究 >> 论文成果

Universal Host Materials for High-Efficiency Phosphorescent and Delayed-Fluorescence OLEDs

点击次数:

论文类型:期刊论文

发表时间:2015-12-02

发表刊物:ACS APPLIED MATERIALS & INTERFACES

收录刊物:SCIE、EI、PubMed、Scopus

卷号:7

期号:47

页面范围:26206-26216

ISSN号:1944-8244

关键字:phosphorescent organic light-emitting diodes (OLEDs); thermally activated delayed fluorescence (TADF); bipolar host; universal host materials; pyrazole

摘要:A series of bipolar hosts, namely, 5-(2-(9H-carbazol-9-yl)-phenyl)-1,3-dipyrazolbenzene (o-CzDPz), 5-(3-(9H-carbazol-9-yl)-phenyl)-1,3-dipyrazolbenzene (m-CzDPz), 5-(9-phenyl-9H-carbazol-3-yl)-1,3-dipyrazolbenzene (3-CzDPz), and 5-(3,5-di(9H-carbazol-9-yl)-phenyl)-1,3-dipyrazolbenzene (mCPDPz), are developed for phosphorescent and thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs). They are designed by selecting pyrazole as n-type unit and carbazole as p-type one. The triplet energy (E-T), the frontier molecular orbital level, and charge transporting abilities, are adjusted by varying the molar ratio of pyrazole to carbazole and the linking mode between them. They have high E-T values of 2.76-3.02 eV. Their electroluminescence performance is evaluated by fabricating both phosphorescent and TADF devices with blue or green emitters. The m-CzDPz hosted blue phosphorescent OLEDs achieves high efficiency of 48.3 cd A(-1) (26.8%), the 3-CzDPz hosted green phosphorescent device exhibits 91.2 cd A(-1) (29.0%). The blue and green TADF devices with 3-CzDPz host also reach high efficiencies of 26.2 cd A(-1) (15.8%) and 41.1 cd A(-1) (13.3%), respectively. The excellent performance of all these OLEDs verifies that these pyrazole-based bipolar compounds are capable of being universal host materials for OLED application. The influence of molar ratio of n-type unit to p-type one and the molecular conformation of these hosts on their device performance is discussed and interpreted.