High-efficiency diphenylsulfon derivatives-based organic light-emitting diode exhibiting thermally activated delayed fluorescence

TL;DR

This study theoretically investigates novel TADF materials based on diphenyl sulfone with different donors, demonstrating potential for efficient blue OLED emission due to small singlet-triplet energy gaps and suitable emission wavelengths.

Contribution

It introduces a new theoretical approach to designing TADF materials with optimized donor-acceptor structures for blue OLED applications.

Findings

TMC-DPS has a small ΔEST of 0.094 eV, favorable for TADF.

TMC-DPS exhibits a blue emission at 439.9 nm.

Theoretical calculations suggest TMC-DPS as a promising blue OLED emitter.

Abstract

Novel thermally activated delayed fluorescence (TADF) material with diphenyl sulfone (DPS) as an electron acceptor and 3,6-dimethoxycarbazole (DMOC) and 1,3,6,8-Tetramethyl-9H-carbazole (TMC) as electron donors were investigated theoretically for a blue organic light emitting diode (OLED) emitter. We calculate the energies of the first singlet (S1) and first triplet (T1)-excited states of TADF materials by performing density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations on the ground state using a dependence on charge transfer amounts for the optimal Hartree-Fock percentage in the exchange-correlation of TD-DFT. The calculated {\Delta}EST values of TMC-DPS (0.094 eV) was smaller than DMOC-DPS (0.386 eV) because of the large dihedral angles between the donor and accepter moieties. We show that TMC-DPS would have a suitable blue OLED emitter, because it has a large dihedral angle that creates a small spatial overlap between the HOMO and the LUMO and, consequently, the small {\Delta}EST and the emission wavelength of 2.82 eV (439.9 nm).