Klein, Marius and Rau, Nicholas and Wende, Mirco and Sundermeyer, Joerg and Cheng, Gang and Che, Chi-Ming and Schinabeck, Alexander and Yersin, Hartmut (2020) Cu(I) and Ag(I) Complexes with a New Type of Rigid Tridentate N,P,P-Ligand for Thermally Activated Delayed Fluorescence and OLEDs with High External Quantum Efficiency. CHEMISTRY OF MATERIALS, 32 (24). pp. 10365-10382. ISSN 0897-4756, 1520-5002
Full text not available from this repository. (Request a copy)Abstract
Neutral Cu(I) and Ag(I) complexes with a new rigid tridentate N,P,P ligand (dmpzpp, 3,5-dimethyl-1-(2-((2-(di-o-tolyl)-phosphanyl) (o-tolyI)-phosphanyl)phenyl)-1H-pyrazole), giving Cu-(dmpzpp)Cl 6, Cu(dmpzpp)Br 7, Cu(dmpzpp)I 8, Cu(dmpzpp)SPh 9, and Ag(dmpzpp)I 10 with SPh = thiophenylato, were prepared and their crystal structures, TD-DFT electronic structures, and phosphorescence and thermally activated delayed fluorescence (TADF) properties were studied in detail. The photoluminescence quantum yields Phi(PL) of neat powder materials lie between 70 and 90% with emission colors from blue to yellow. Compound 9, with bulky ligands showing 0,, = 90%, was used for detailed emission studies from T = 1.7 to 300 K. Up to T approximate to 70 K, 9 shows only long-lived phosphorescence with a radiative decay time of T-1 of tau(r)(phos) = 1 ms because of weak spin-orbit coupling. Accordingly, the zerofield splittings of T-1 in three substates are < 1 cm(-1) (0.1 meV). Individual decay times of 2400, 2250, and 292 mu s are estimated. Presumably, the phosphorescence is essentially induced by spin-vibronic mechanisms. Up to T = 300 K, the radiative decay time decreases by more than two orders of magnitude to T(TADF) = 5.6 mu s because of the TADF effect. This short decay time is determined by the small gap of Delta E(S-1-T-1) = 600 cm(-1) (74 meV) and the fast radiative S-1 -> S-0 rate of 1.1 x 10(7) s(-1) (91 ns). For fabrication of OLED devices, we applied sublimable 8 and 9 using cohost device structures. For example, with a concentration of 2 wt % of 8, a green-emitting OLED showing CIE coordinates of (0.33; 0.52), a high external quantum efficiency of up to EQE = 16.4%, and a high luminance of almost 10,000 cd m(-2) could be fabricated. Strategies for designing compounds giving higher EQE are presented.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | LIGHT-EMITTING-DIODES; PHOTOINDUCED STRUCTURAL-CHANGE; ZETA VALENCE QUALITY; AUXILIARY BASIS-SETS; COPPER(I) COMPLEXES; EXCITED-STATE; CHARGE-TRANSFER; PHOTOPHYSICAL PROPERTIES; MOLECULAR-STRUCTURE; TRIPLET EMITTERS; |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie > Chair of Chemistry III - Physical Chemistry (Molecular Spectroscopy and Photochemistry) Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie > Chair of Chemistry III - Physical Chemistry (Molecular Spectroscopy and Photochemistry) > Prof. Dr. Hartmut Yersin |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 05 Mar 2021 07:30 |
| Last Modified: | 05 Mar 2021 07:30 |
| URI: | https://pred.uni-regensburg.de/id/eprint/43100 |
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