Color-stable all-fluorescent WOLEDs with single bipolar host based on a red TADF emitter

4th International Conference on Applied Materials and Manufacturing Technology

材料科学;机械制造

Dong, He^1,2 ; Jiang, Hai-Peng^2 ; Wang, Jin^2 ; Gao, Xin^1

State Key Laboratory of High Power Semiconductor Laser, Changchun University of Science and Technology, Changchun

130000, China^1

Key Laboratory of Functional Materials Physics and Chemistry, Ministry of Education, College of Information Technology, Jilin Normal University, Siping

136000, China^2

关键词: Color rendering index;    Exciton recombination zones;    Fluorescent emitters;    High color rendering index;    Stable emissions;    Thermally activated delayed fluorescences;    White emissions;    White organic light-emitting devices;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/423/1/012145/pdf
DOI  :  10.1088/1757-899X/423/1/012145

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

High color rendering index and color-stable all-fluorescent white organic light-emitting devices (WOLEDs) with a red thermally activated delayed fluorescence(TADF) emitter using 2,3,5,6-tetrakis(3,6-diphenylcarbazol-9-yl)-1,4-dicyanobenzene (4CzTPN-Ph) and a blue fluorescent emitter (DSA-Ph) doped in a bipolar host emitter were fabricated. Extended exciton recombination zone by a bipolar host emitter contributes to balance the distribution of carriers in the emitting layer. The device exhibits high color stable white emission with a slight Commission International de l'Eclairage (CIE) coordinates variation of (0.002, 0.001) at a luminance ranging from 500 cd m-2 to 5000 cd m-2, the CIE coordinate of (0.40, 0.38) and the CRI up to 74. These results indicate that the application of a single bipolar host, a spacer-free layer structure, and a TADF emitter has a significant effect on achieving spectrally stable emission, improving the color rendering index, and reducing the efficiency roll-off of the fluorescent WOLEDs.