Theoretically elucidating high photoluminescence performance of dimethylacridan-based blue-color thermally activated delayed fluorescent materials

Abstract

Organic donor-acceptor (D-A) type thermally activated delayed fluorescence (TADF) materials exhibit high luminous quantum efficiencies and therefore attract considerable research interests as organic light-emitting diodes (OLEDs). Accurately calculating the photoluminescence...

Carbonyl (CO)/N-based thermally activated delayed fluorescent materials with high efficiency and fast reverse intersystem crossing rate: a theoretical design and study

“…In following MOMAP calculations, we adopted the molecular internal coordinates and did not consider the Duschinsky rotation effects. 7,76 In the MOMAP, the excited state properties, such as adiabatic excitation energy, TDM, SOC and reorganization energy, are crucial parameters to determining the photophysical performance of TADF molecules. 56…”

“…Organic light-emitting diodes (OLEDs) based on thermally activated delayed fluorescence (TADF) materials exhibit advantages for use in high-efficiency and low-cost displays and are considered the next-generation OLED technology. [1][2][3][4][5][6][7] The feature of TADF is the efficient conversion from the triplet-excited state to the singlet state by the reverse intersystem crossing (RISC) process and can achieve a theoretical internal quantum efficiency (IQE) of 100%. 2,[8][9][10][11] In principle, a small energy gap DE ST between the lowest singlet excited state S 1 and the lowest triplet excited state T 1 is crucial to achieving fast RISC rates and low efficiency roll-off.…”

“…The geometrical and electronic structures of TADF materials can be evaluated by using the first principles methods, 8,[50][51][52][53][54][55] while the corresponding photophysical performance can be predicted based on the excited state properties. 7,56 Moreover, the multiscale quantum mechanics and molecular mechanics (QM/MM) methods have been proposed to investigate the effects of the film environment 57 and molecular aggregation 58 on the photophysical properties. By analyzing the relationship between the excited state properties and photophysical performance, we can design new highly efficient TADF molecules with balanced transition dipole moment and DE ST .…”

Predicting and Designing Thermally Activated Delayed Fluorescence Molecules with Balanced ΔEST and Transition Dipole Moment

“…[26] Therefore, it is still a challenge to design efficient OLED materials, on the basis of the photophysical performance dependency of TADF molecules on their geometrical and electronic structures, and aggregation effects. [27,28] Recently, many efforts have been devoted to design efficient TADF molecules by engineering molecular structures based on the structure-property relationships. [6,13,29,30] Based on the triptycene skeleton linking the donor and acceptor moieties, the TADF molecules with 3D configurations can realize small ΔE ST and suppressed vibrational relaxation leading to the reduction of nonradiative rates.…”

“…[ 26 ] Therefore, it is still a challenge to design efficient OLED materials, on the basis of the photophysical performance dependency of TADF molecules on their geometrical and electronic structures, and aggregation effects. [ 27,28 ]…”