Thermally activated delayed fluorescence host materials based on triphenylphosphine oxide derivatives. (24th May 2019)

• Record Type: Journal Article
• Authors: Choi, Dong Ho; Kim, Young Sik
• Is Part Of: Molecular crystals and liquid crystals. Volume 685(2019)
• Page Start: 71
• Page End: 77
• Publication Date: 2019-05-24
• Subjects: density functional theory (DFT) -- time-dependent density functional theory (TD-DFT) -- organic light-emitting diode (OLED) -- thermally activated delayed fluorescence (TADF); Molecular crystals -- Periodicals; Liquid crystals -- Periodicals; Liquid crystals; Molecular crystals; Periodicals; 548
• DOI: 10.1080/15421406.2019.1645463
• Languages: English
• ISSNs: 1542-1406

Abstract

Abstract: Novel thermally activated delayed fluorescence (TADF) host molecules for blue electrophosphorescence were developed by combining the electron donor acridine derivatives with the electron acceptor triphenylphosphine oxide unit in a single molecule based on density functional theory. We obtained the energies of the first excited singlet (S1 ) and triplet (T1 ) states of the TADF materials by performing procedures in accordance with density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations to the ground state using dependence on the charge transfer amounts for the optimal Hartree-Fock percentage in the exchange-correlation of TD-DFT. Using DFT and TD-DFT calculations, the significant separation between the HOMO and LUMO caused a small difference in energy (ΔEST ) between the S1 and T1 states. The host molecules retained high triplet energy and showed great potential for use in blue phosphorescent organic light-emitting diodes. The results also showed that these molecules are promising TADF host materials because they demonstrate a low barrier to hole and electron injection, balanced charge transport for both holes and electrons, and small ΔEST .