Donor–acceptor materials exhibiting deep blue emission and thermally activated delayed fluorescence with tris(triazolo)triazine

2021 ◽  
Author(s):  
Ryoga Hojo ◽  
Don M. Mayder ◽  
Zachary M. Hudson
Keyword(s):  
Blue Emission ◽  
Delayed Fluorescence ◽  
Fluorescence Properties ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Two Photon ◽  
Deep Blue ◽  
Donor Acceptor ◽  
Two Photon Fluorescence ◽  
Photon Fluorescence

Five emitters with the tris(triazolo)triazine acceptor core are reported, with emission from deep blue to green. These emitters show promising thermally activated delayed fluorescence and/or two-photon fluorescence properties.

scholarly journals (Deep) blue through-space conjugated TADF emitters based on [2.2]paracyclophanes

2018 ◽  
Vol 54 (67) ◽  
pp. 9278-9281 ◽  
Author(s):  
Eduard Spuling ◽  
Nidhi Sharma ◽  
Ifor D. W. Samuel ◽  
Eli Zysman-Colman ◽  
Stefan Bräse
Keyword(s):  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Deep Blue ◽  
Donor Acceptor

The first examples of through-space conjugated thermally activated delayed fluorescence (TADF) emitters based on a [2.2]paracyclophane (PCP) skeleton with stacked (coplanar) donor–acceptor groups have been synthesized.

scholarly journals Efficient Deep-Blue Electroluminescence Employing Heptazine-Based Thermally Activated Delayed Fluorescence

Photonics ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 293
Author(s):  
Jie Li ◽  
Jincheng Zhang ◽  
Heqi Gong ◽  
Li Tao ◽  
Yanqing Wang ◽  
...  
Keyword(s):  
High Performance ◽  
Light Emitting Diode ◽  
Blue Emission ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Thermally Activated ◽  
Deep Blue ◽  
Blue Emitters

We report an efficient deep-blue organic light-emitting diode (OLED) based on a heptazine-based thermally activated delayed fluorescent (TADF) emitter, 2,5,8-tris(diphenylamine)-tri-s-triazine (HAP-3DPA). The deep-blue-emitting compound, HAP-3DPA, was designed and synthesized by combining the relatively rigid electron-accepting heptazine core with three electron-donating diphenylamine units. Due to the rigid molecular structure and intramolecular charge transfer characteristics, HAP-3DPA in solid state presented a high photoluminescence quantum yield of 67.0% and obvious TADF nature with a short delayed fluorescent lifetime of 1.1 μs. Most importantly, an OLED incorporating HAP-3DPA exhibited deep-blue emission with Commission Internationale de l’Eclairage (CIE) coordinates of (0.16, 0.13), a peak luminance of 10,523 cd/m−2, and a rather high external quantum efficiency of 12.5% without any light out-coupling enhancement. This finding not only reports an efficient deep-blue TADF molecule, but also presents a feasible pathway to construct high-performance deep-blue emitters and devices based on the heptazine skeleton.

scholarly journals Pyrimidine-based twisted donor–acceptor delayed fluorescence molecules: a new universal platform for highly efficient blue electroluminescence

2017 ◽  
Vol 8 (2) ◽  
pp. 953-960 ◽  
Author(s):  
In Seob Park ◽  
Hideaki Komiyama ◽  
Takuma Yasuda
Keyword(s):  
High Efficiency ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Highly Efficient ◽  
Deep Blue ◽  
Donor Acceptor

High-efficiency deep blue thermally activated delayed fluorescence (TADF) emitters consisting of acridan–pyrimidine donor–acceptor motifs are developed.

scholarly journals Exploring the possibility of using fluorine-involved non-conjugated electron-withdrawing groups for thermally activated delayed fluorescence emitters by TD-DFT calculation

2021 ◽  
Vol 17 ◽  
pp. 210-223
Author(s):  
Dongyang Chen ◽  
Eli Zysman-Colman
Keyword(s):  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Delayed Fluorescence ◽  
Type I ◽  
Type Ii ◽  
Triplet Energy ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Deep Blue ◽  
Donor Acceptor

The trifluoromethyl group has been previously explored as a non-conjugated electron-withdrawing group in donor–acceptor thermally activated delayed fluorescence (TADF) emitters. In the present study, we investigate computationally the potential of other fluorine-containing acceptors, trifluoromethoxy (OCF3), trifluoromethylthio (SCF3), and pentafluorosulfanyl (SF5), within two families of donor–acceptor TADF emitters. Time-dependent density functional theory calculations indicate that when only two ortho-disposed carbazole donors are used (Type I molecules), the lowest-lying triplet state possesses locally excited (LE) character while the lowest-lying singlet state possesses charge-transfer character. When five carbazole donors are present in the emitter design (Type II molecules), now both S1 and T1 states possess CT character. For molecules 2CzOCF 3 and 5CzOCF 3 , the singlet energies are predicted to be 3.92 eV and 3.45 eV; however, the singlet-triplet energy gaps, ΔE STs, are predicted to be large at 0.46 eV and 0.37 eV, respectively. The compounds 2CzCF 3 , 2CzSCF 3 , and 2CzSF 5 , from Type I molecules, show significant promise as deep blue TADF emitters, possessing high calculated singlet energies in the gas phase (3.62 eV, 3.66 eV, and 3.51 eV, respectively) and small, ΔE STs, of 0.17 eV, 0.22 eV, and 0.07 eV, respectively. For compounds 5CzSCF 3 and 5CzSF 5 , from Type II molecules, the singlet energies are stabilized to 3.24 eV and 3.00 eV, respectively, while ΔE STs are 0.27 eV and 0.12 eV, respectively, thus both show promise as blue or sky-blue TADF emitters. All these six molecules possess a dense number of intermediate excited states between S1 and T1, thus likely leading to a very efficient reverse intersystem crossing in these compounds.

Frustrated Lewis pairs with thermally activated delayed fluorescence properties: activation of formaldehyde

2020 ◽  
Vol 49 (38) ◽  
pp. 13198-13201
Author(s):  
Young Hoon Lee ◽  
Eun Bi Nam ◽  
Junseong Lee ◽  
Sang Uck Lee ◽  
Min Hyung Lee
Keyword(s):  
Delayed Fluorescence ◽  
Fluorescence Properties ◽  
Frustrated Lewis Pairs ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Donor Acceptor ◽  
Lewis Pairs

Activation of formaldehyde (FA) by frustrated Lewis pairs (FLPs) consisting of bulky phosphines with a donor–acceptor unit and B(C6F5)3 led to the formation of FLP–FA adducts that exhibit a thermally activated delayed fluorescence.

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