Xu Yincai, Wang Qingyang, Cai Xinliang, Li Chenglong, Wang Yue
State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China.
Jihua Laboratory, 28 Huandao South Road, Foshan, Guangdong Province, 528200, P. R. China.
Adv Mater. 2021 May;33(21):e2100652. doi: 10.1002/adma.202100652. Epub 2021 Apr 17.
Purely organic fluorescent materials that concurrently exhibit high efficiency, narrowband emission, and circularly polarized luminescence (CPL) remain an unaddressed issue despite their promising applications in wide color gamut- and 3D-display. Herein, the CPL optical property and multiple resonance (MR) effect induced thermally activated delayed fluorescence (MR-TADF) emission are integrated with high color purity and luminous efficiency together. Two pairs of highly efficient green CP-MR-TADF enantiomers, namely, (R/S)-OBN-2CN-BN and (R/S)-OBN-4CN-BN, are developed. The enantiomer-based organic light-emitting diodes (OLEDs) exhibit pure green emission with narrow full-width at half-maximums (FWHMs) of 30 and 33 nm, high maximum external quantum efficiencies (EQEs) of 29.4% and 24.5%, and clear circularly polarized electroluminescence (CPEL) signals with electroluminescence dissymmetry factors (g ) of +1.43 × 10 /-1.27 × 10 and +4.60 × 10 /-4.76 × 10 , respectively. This is the first example of a highly efficient OLED that exhibits CPEL signal, narrowband emission, and TADF concurrently.
尽管纯有机荧光材料在广色域和3D显示中有广阔应用前景，但同时具备高效率、窄带发射和圆偏振发光（CPL）的纯有机荧光材料仍是一个未解决的问题。在此，将CPL光学性质和多共振（MR）效应诱导的热激活延迟荧光（MR-TADF）发射结合在一起，实现了高色纯度和发光效率。开发了两对高效的绿色CP-MR-TADF对映体，即（R/S）-OBN-2CN-BN和（R/S）-OBN-4CN-BN。基于对映体的有机发光二极管（OLED）发出纯绿色光，半高宽分别为30和33nm，最大外量子效率（EQE）分别高达29.4%和24.5%，并且具有清晰的圆偏振电致发光（CPEL）信号，电致发光不对称因子（g）分别为+1.43×10 /-1.27×10和+4.60×10 /-4.76×10。这是首个同时展现出CPEL信号、窄带发射和TADF的高效OLED实例。
