Efficient Sky‐Blue Organic Light‐Emitting Diodes Using a Highly Horizontally Oriented Thermally Activated Delayed Fluorescence Emitter. Issue 23 (23rd October 2020)

• Record Type: Journal Article
• Authors: Zhang, Zhen; Crovini, Ettore; dos Santos, Paloma L.; Naqvi, Bilal A.; Cordes, David B.; Slawin, Alexandra M. Z.; Sahay, Prakhar; Brütting, Wolfgang; Samuel, Ifor D. W.; Bräse, Stefan; Zysman‐Colman, Eli
• Is Part Of: Advanced optical materials. Volume 8:Issue 23(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-10-23
• Subjects: acceptor–donor–acceptor emitters -- blue emitters -- horizontal orientation -- indolocarbazole -- organic light‐emitting diodes -- out‐coupling effect -- thermally activated delayed fluorescence emitters -- triazine; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.202001354
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: Organic thermally activated delayed fluorescent (TADF) materials can harvest 100% of the electrically generated excitons as a result of their small singlet–triplet energy difference. However, maximizing the external quantum efficiency (EQE) of a device also requires enhancing the light out‐coupling efficiency. This work presents a new acceptor–donor–acceptor (ADA) emitter employing an indolocarbazole donor and diphenyltriazine acceptors that show nearly‐completely horizontal orientation regardless of the host matrix, leading to a sky‐blue organic light‐emitting diode (λEL = 483 nm, CIE coordinates of 0.17, 0.32) with EQEMAX of 22.1%, a maximum luminance of 7800 cd m −2, and blue emission. Abstract : A bright sky‐blue acceptor–donor–acceptor thermally activated delayed fluorescence emitter that shows near horizontal orientation in doped films is reported. The organic light‐emitting diode shows a maximum external quantum efficiency of 22.1%.