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-59
Subject Impact of Donor and Acceptor Substitution on the Thermally Activated Delayed Fluorescence Properties in the Ortho–Carbazole-Appended Triarylboron Derivatives
Authors Young Hoon Lee, Heechai Lee, Juhee Kim, Min Hyung Lee*
Department of Chemistry, University of Ulsan, Korea
Abstract In this work, we report on the synthesis and photophysical investigation of a series of highly efficient blue TADF materials based on the ortho–carbazole-linked triarylboron compounds (1–5) including carbazoyl unit as a donor (D) and triarylboron as an acceptor (A), respectively. The emission color of these donor-acceptor TADF emitters were finely tuned by introducing electron-donating tertiary butyl (Bu) substituents on the donor and methyl (Me) or methoxy (OMe) substituents on the acceptor units, respectively. X-ray crystal structure analysis of BuCzoB (1) showed a highly twisted D–A structure, leading to small singlet-triplet energy splitting. Remarkably, a high EQE value over 30% at CIE color coordinates of (0.135, 0.266) was obtained using BuCzMeoB (2) as the dopant. This result is ascribed to both the high quantum efficienty of 2 in the host film (93%) and the high horizontal transition dipole ratio (Θ) of 0.76. Ultra-deep blue OLEDs with a record-high efficiency are also fabricated with a CzOMeoB (5) emitter, exhibiting an EQE of 14.9% at CIE coordinates of (0.151, 0.058).
E-mail dasis75@hanmail.net