Photophysics of OLED Materials with Emitters Exhibiting Thermally Activated Delayed Fluorescence and Used in Hole/Electron Transporting Layer from Optimally Tuned Range-Separated Density Functional Theory

2018 ◽  
Vol 123 (1) ◽  
pp. 746-761 ◽  
Author(s):  
Mojtaba Alipour ◽  
Zahra Safari
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Delayed Fluorescence ◽  
Functional Theory ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Electron Transporting Layer

Potential thermally activated delayed fluorescence properties of a series of 2,3-dicyanopyrazine based compounds

2018 ◽  
Vol 3 (7) ◽  
Author(s):  
Ayşegül Gümüş ◽  
Selçuk Gümüş
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Delayed Fluorescence ◽  
Basis Sets ◽  
Functional Theory ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Structural And Electronic Properties ◽  
Donor Acceptor ◽  
Almost All

Abstract 2,3-Dicyanopyrazine based acceptor was combined with a series of well studied donors to obtain donor-acceptor type potential thermally activated delayed fluorescence emitters. Their structural and electronic properties were computed theoretically at the level of density functional theory and time dependent density functional theory with the application of two different hybrid functionals and various basis sets. Almost all of the designed structures were computed to have the potential of being TADF compounds since they possess very narrow singlet-triplet gaps. Indeed, acridine-pyrazine (9) derivative was calculated to be the best candidate for the purpose among them.

Computational study on thermally activated delayed fluorescence of donor–linker–acceptor network molecules

RSC Advances ◽  
2016 ◽  
Vol 6 (43) ◽  
pp. 37203-37211 ◽  
Author(s):  
Talapunur Vikramaditya ◽  
Mukka Saisudhakar ◽  
Kanakamma Sumithra
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Organic Molecules ◽  
Computational Study ◽  
Delayed Fluorescence ◽  
Structure Property ◽  
Functional Theory ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Structure Property Relationships

Using density functional theory we have investigated the structure–property relationships of organic molecules with a donor–linker–acceptor (DLA) framework, which can be used as precursors of OLED materials.

Theoretical Study on Benzazole Derivatives for Use in Blue Thermally Activated Delayed Fluorescence Emitters

2015 ◽  
Vol 15 (10) ◽  
pp. 7819-7822 ◽  
Author(s):  
Dong Yuel Kwon ◽  
Geon Hyeong Lee ◽  
Young Sik Kim
Keyword(s):  
Density Functional Theory ◽  
Molecular Orbital ◽  
Density Functional ◽  
Light Emitting Diode ◽  
Energy Difference ◽  
Delayed Fluorescence ◽  
Functional Theory ◽  
Thermally Activated Delayed Fluorescence ◽  
Organic Light Emitting Diode ◽  
Thermally Activated

Four novel thermally activated delayed fluorescence (TADF) materials with 9,10-dihydro-9,9- dimethylacridine (DMAC) and phenylindolo(2,3-a)carbazole (PIC) as electron donors and benzazole derivatives (BO, and BT) as electron acceptors (DMAC-BO, DMAC-BT, PIC-BO, and PIC-BT) were designed and theoretically investigated for use as a blue organic light emitting diode (OLED) emitter. Using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations, we calculated the electron distribution of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), and the energy of the lowest singlet (S1) and the lowest triplet (T1) excited states. All the dyes had a small spatial overlap between the HOMO and LUMO because of the relatively large dihedral angle between the phenyl ring and the acceptor moiety. In terms of the energy difference (ΔEST) between the S1 state and the T1 state, DMAC-BO and DMAC-BT showed the small ΔEST (0.18 eV and 0.21 eV, respectively). However, PIC-BO and PIC-BT showed the large ΔEST (0.62 eV and 0.61 eV, respectively). Among the TADF materials, we showed that DMAC-BO would have the best TADF properties in terms of small ΔEST and blue OLED emitters

scholarly journals Solution-Processed OLEDs Based on Thermally Activated Delayed Fluorescence Copper(I) Complexes with Intraligand Charge-Transfer Excited State

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1125
Author(s):  
Teng Teng ◽  
Jinfan Xiong ◽  
Gang Cheng ◽  
Changjiang Zhou ◽  
Xialei Lv ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Density Functional ◽  
Delayed Fluorescence ◽  
Quantum Yields ◽  
Functional Theory ◽  
Solution Processed ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Thermally Activated ◽  
Wide Range

A new series of tetrahedral heteroleptic copper(I) complexes exhibiting efficient thermally-activated delayed fluorescence (TADF) in green to orange electromagnetic spectral regions has been developed by using D-A type N^N ligand and P^P ligands. Their structures, electrochemical, photophysical, and electroluminescence properties have been characterized. The complexes exhibit high photoluminescence quantum yields (PLQYs) of up to 0.71 at room temperature in doped film and the lifetimes are in a wide range of 4.3–24.1 μs. Density functional theory (DFT) calculations on the complexes reveal the lowest-lying intraligand charge-transfer excited states that are localized on the N^N ligands. Solution-processed organic light emitting diodes (OLEDs) based on one of the new emitters show a maximum external quantum efficiency (EQE) of 7.96%.

Theoretical Study of Phenoxaphosphine-Based Blue Organic Light-Emitting Diode Exhibiting Thermally Activated Delayed Fluorescence

2020 ◽  
Vol 20 (11) ◽  
pp. 7187-7190
Author(s):  
JaMin Lee ◽  
Sae Won Lee ◽  
Young Sik Kim
Keyword(s):  
Density Functional ◽  
Light Emitting Diode ◽  
Energy Difference ◽  
Delayed Fluorescence ◽  
Functional Theory ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Thermally Activated ◽  
Organic Light

We designed novel thermally activated delayed fluorescence (TADF) materials by combining the electron donors spiro[acridine-9,9′-fluorene] (D1) and 9,9-diphenyl acridan (PAC) with the electron acceptor phenoxaphosphine (OPO) unit (2D1-OPO and 2PAC-OPO) and used those property to compare it with that of the reference material using dimethylacridan (Ac) as an electron donor (Ac-OPO) for blue organic light-emitting diodes (OLEDs). To calculate electron distribution of highest occupied molecular orbitals (HOMO), lowest occupied molecular orbital (LUMO), lowest singlet (S1) energy and lowest triplet (T1) excitation states, density functional theory (DFT) and time-dependent DFT calculation have been used. The calculated energy difference (ΔEST) between the S1 and T1 states of 2D1-OPO (0.125 eV) and 2PAC-OPO (0.153 eV) were as small as that of Ac-OPO (0.127 eV). The results showed that 2D1-OPO is a good candidate for blue OLED emitter because it has an emission wavelength of 441.0 nm as well as a sufficiently small ΔEST value and large oscillator intensity value.

Highly Charge Transport Thermally Activated Delayed Fluorescence Host Materials Based on Benzimidazole-Acridine Derivatives

2020 ◽  
Vol 20 (8) ◽  
pp. 5070-5074
Author(s):  
Ja Min Lee ◽  
Sae Won Lee ◽  
Young Sik Kim
Keyword(s):  
Dft Calculations ◽  
Charge Transport ◽  
Density Functional ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Host Molecules ◽  
Acridine Derivatives ◽  
Host Materials ◽  
Td Dft

We designed novel thermally activated delayed fluorescence (TADF) host molecules for blue electrophosphorescence by combining the electron acceptor benzimidazole (BI) unit and the electron donor acridine derivatives into a single molecular unit based on density functional theory (DFT). We obtained the energies of the first singlet (S1) and the first triplet (T1) excited states of the TADF materials by performing DFT and time-dependent DFT (TD-DFT) calculations to the ground state using dependence on charge transfer amounts for the optimal Hartree-Fock percentage in the exchange-correlation of TD-DFT. Using DFT and TD-DFT calculations, the large 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 showed that these molecules are promising TADF host materials because they have a low barrier to hole and electron injection, balanced charge transport for both holes and electrons, and a small ΔEST.

scholarly journals Lock-and-Key Exciplexes for Thermally Activated Delayed Fluorescence

2020 ◽  
Vol 02 (01) ◽  
pp. 001-010
Author(s):  
Constantin-Christian A. Voll ◽  
Georgios Markopoulos ◽  
Tony C. Wu ◽  
Matthew Welborn ◽  
Jens U. Engelhart ◽  
...  
Keyword(s):  
Density Functional ◽  
Materials Science ◽  
Visible Spectrum ◽  
Density Functional Theory Calculations ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting Devices ◽  
Thermally Activated ◽  
Emission Color ◽  
Exciplex Emission

We combine synthetic supramolecular chemistry and materials science to develop novel exciplexes for thermally activated delayed fluorescence. Our approach starts from a bowl-shaped acceptor molecule for which we synthesize tailor-made donors that bind in a lock-and-key fashion. The donor design is guided by extensive density functional theory calculations of three independent donor families. The investigation of a large number of custom-synthesized donors allows us to derive empirical relationships for the prediction of the exciplex emission color. Incorporated within organic light-emitting devices, the lock-and-key exciplexes yield external quantum efficiencies of up to 5.4%, with potentially tunable emission color across the blue and green visible spectrum.

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