Circularly Polarized White Organic Light‐Emitting Diodes Based on Spiro‐Type Thermally Activated Delayed Fluorescence Materials. Issue 23 (5th April 2022)

• Record Type: Journal Article
• Authors: Zhang, Yi‐Pin; Mao, Meng‐Xi; Song, Shi‐Quan; Wang, Yi; Zheng, You‐Xuan; Zuo, Jing‐Lin; Pan, Yi
• Is Part Of: Angewandte Chemie international edition. Volume 61:Issue 23(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-04-05
• Subjects: Circularly Polarized Luminescence -- Spiro Compounds -- Thermally Activated Delayed Fluorescence -- White CP-OLEDs; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202200290
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: In this study, we report the first circularly polarized white organic light‐emitting diodes (CP‐WOLEDs) based on all thermally activated delayed fluorescence (TADF) materials. Two pairs of spiro‐type TADF enantiomers, ( R / S )‐SPOCN (5, 5′‐((2, 2′, 3, 3′‐tetrahydro‐1, 1′‐spirobi[indene]‐7, 7′‐diyl)bis(oxy))bis(4‐(10 H ‐phenoxazin‐10‐yl)phthalonitrile)) and ( R / S )‐OSFSO (2′‐(trifluoromethyl)‐spiro[quinolino[3, 2, 1‐ kl ]phenoxazine‐9, 9′‐thioxanthene]‐10′, 10′‐dioxide), serve as emitters with complementary emission. The CP‐OLEDs exhibit warm white emission with a CIE coordinate of (0.35, 0.46). Besides, decent device performances are observed with an external quantum efficiency of up to 21.6 % at maximum and 11.8 % at 1000 cd m −2 . Obvious circularly polarized electroluminescence signals are detected with a dissymmetry factor | g EL | of around 3.0×10 −3 . This is the first report of CP‐WOLEDs that can harvest both singlet and triplet excitons, which provides a feasible strategy for the development of CP‐WOLEDs with remarkable device performances. Abstract : Circularly polarized white organic light‐emitting diodes that can harvest both singlet and triplet excitons have been developed by combining two pairs of spiro‐type circularly polarized delayed fluorescence enantiomers with complementary emissions as chiral emissive layers. Remarkable device performances are observed, with an external quantum efficiency of up to 21.6 % and intense circularly polarized luminescence having a | g EL | factor of 3.0×10 −3 .