scholarly journals Red-shifted delayed fluorescence at the expense of photoluminescence quantum efficiency – an intramolecular charge-transfer molecule based on a benzodithiophene-4,8-dione acceptor

2019 ◽  
Vol 21 (20) ◽  
pp. 10580-10586 ◽  
Author(s):  
Stephanie Montanaro ◽  
Alexander J. Gillett ◽  
Sascha Feldmann ◽  
Emrys W. Evans ◽  
Felix Plasser ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Quantum Efficiency ◽  
Intramolecular Charge Transfer ◽  
Delayed Fluorescence ◽  
Donor Acceptor ◽  
Quinone Acceptor

A donor–acceptor compound using a thiophene based quinone acceptor displays strongly red-shifted delayed emission but limited quantum efficiency.

scholarly journals Tuning of Hyperpolarizability, One- and Two-Photon Absorption of D-A and D-A-A Type Intramolecular Charge Transfer Based Sensors

2019 ◽  
Author(s):  
Pralok K. Samanta ◽  
Md Mehboob Alam ◽  
Ramprasad Misra ◽  
Swapan K. Pati
Keyword(s):  
Charge Transfer ◽  
Gas Phase ◽  
Density Functional ◽  
Intramolecular Charge Transfer ◽  
Photon Absorption ◽  
First Hyperpolarizability ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Nlo Response ◽  
Donor Acceptor

Solvents play an important role in shaping the intramolecular charge transfer (ICT) properties of π-conjugated molecules, which in turn can affect their one-photon absorption (OPA) and two-photon absorption (TPA) as well as the static (hyper)polarizabilities. Here, we study the effect of solvent and donor-acceptor arrangement on linear and nonlinear optical (NLO) response properties of two novel ICT-based fluorescent sensors, one consisting of hemicyanine and dimethylaniline as electron withdrawing and donating groups (molecule 1), respectively and its boron-dipyrromethene (BODIPY, molecule 2)-fused counterpart (molecule 3). Density functional theoretical (DFT) calculations using long-range corrected CAM-B3LYP and M06-2X functionals, suitable for studying properties of ICT molecules, are employed to calculate the desired properties. The dipole moment (µ) as well as the total first hyperpolarizability (β<sub>total</sub>) of the studied molecules in the gas phase is dominantly dictated by the component in the direction of charge transfer. The ratios of vector component of first hyperpolarizability (β<sub>vec</sub>) to β<sub>total</sub> also reveal unidirectional charge transfer process. The properties of the medium significantly affect the OPA, hyperpolarizability and TPA properties of the studied molecules. Time dependent DFT (TDDFT) calculations suggest interchanging between two lowest excited states of molecule 3 from the gas phase to salvation. The direction of charge polarization and dominant transitions among molecular orbitals involved in the OPA and TPA processes are studied. The results presented are expected to be useful in tuning the NLO response of many ICT-based chromophores, especially those with BODIPY acceptors.<br>

scholarly journals Synthesis and optoelectronic properties of benzoquinone-based donor–acceptor compounds

2019 ◽  
Vol 15 ◽  
pp. 2914-2921
Author(s):  
Daniel R Sutherland ◽  
Nidhi Sharma ◽  
Georgina M Rosair ◽  
Ifor D W Samuel ◽  
Ai-Lan Lee ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Delayed Fluorescence ◽  
Optoelectronic Properties ◽  
Donor Group ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Palladium Catalyzed ◽  
Donor Acceptor

Herein, we report a mild and efficient palladium-catalyzed C–H functionalization method to synthesize a series of benzoquinone (BQ)-based charge-transfer (CT) derivatives in good yields. The optoelectronic properties of these compounds were explored both theoretically and experimentally and correlations to their structures were identified as a function of the nature and position of the donor group (meta and para) attached to the benzoquinone acceptor. Compound 3, where benzoquinone is para-conjugated to the diphenylamine donor group, exhibited thermally activated delayed fluorescence (TADF) with a biexponential lifetime characterized by a prompt ns component and a delayed component of 353 μs.

High-performing D–π–A–π–D benzothiadiazole-based hybrid local and charge-transfer emitters in solution-processed OLEDs

2020 ◽  
Vol 8 (47) ◽  
pp. 17009-17015
Author(s):  
Indu Bala ◽  
Rohit Ashok Kumar Yadav ◽  
Manisha Devi ◽  
Joydip De ◽  
Nitya Singh ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Charge Transfer State ◽  
Solution Processed ◽  
High Performing ◽  
Donor Acceptor ◽  
Transfer State

Benzothiadiazole-based donor–acceptor emitters with hybrid local and charge transfer state exhibit high external quantum efficiency in solution-processed green OLEDs.

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