122nd General Meeting of the KCS

Type Poster Presentation
Area Inorganic Chemistry
Room No. Grand Ballroom
Time 10월 19일 (금요일) 11:00~12:30
Code INOR.P-58
Subject Tuning the Delayed Fluorescent Properties of ortho-carbazole-appended triarylboron compounds
Authors Ajay Kumar, Surendran Sujith, Hanif Mubarok, Min Hyung Lee*
Department of Chemistry, University of Ulsan, Korea
Abstract Thermally activated delayed fluorescence (TADF) is one of the effective approaches to harvest the emissive singlet state from a triplet state via reverse intersystem crossing (RISC). Thus, by harvesting both singlet and triplet excitons, an IQE of nearly 100% can be achieved. A very small singlet-triplet energy difference (¡âEST) is required to facilitate efficient RISC. This is usually accomplished by constructing TADF emitters with a twisted donor−acceptor structure, allowing for an effective reduction in the spatial overlap between HOMO and LUMO. Recently, our group reported ortho-donor-appended triarylboron TADF emitters possessing a twisted donor−acceptor structure. In particular, the carbazole donor containing compound (CzoB) exhibited excellent efficiency in pure blue OLED. In this report, we present a series of ortho-carbazole-appended triarylboron compounds (CzRoB, Cz = 9H-carbazolyl, R = electron-withdrawing groups) where the substituents (R) were introduced to the phenylene ring of the triarylboron acceptor moiety to control LUMO level. It was shown that gradual bathochromic shifts in emission wavelength could be attained with increasing the electron-withdrawing strength of R substituent due to the stabilization of LUMO level. All of the compounds exhibit high quantum efficiency (ΦPL) in oxygen-free toluene.
E-mail ajaychem14@gmail.com