Shafikov, Marsel, Daniels, Ruth, Pander, Piotr, Dias, Fernando, Williams, Gareth and Kozhevnikov, Valery (2019) Dinuclear Design of a Pt(II) Complex Affording Highly Efficient Red Emission: Photophysical Properties and Application in Solution-Processible OLEDs. ACS Applied Materials & Interfaces, 11 (8). pp. 8182-8193. ISSN 1944-8244
Full text not available from this repository. (Request a copy)Abstract
The light-emitting efficiency of luminescent materials is invariably compromised on moving to the red and near-infrared regions of the spectrum due to the transfer of electronic excited-state energy into vibrations. We describe how this undesirable “energy gap law” can be sidestepped for phosphorescent organometallic emitters through the design of a molecular emitter that incorporates two platinum(II) centers. The dinuclear cyclometallated complex of a substituted 4,6-bis(2-thienyl)pyrimidine emits very brightly in the red region of the spectrum (λmax = 610 nm, Φ = 0.85 in deoxygenated CH2Cl2 at 300 K). The lowest-energy absorption band is extraordinarily intense for a cyclometallated metal complex: at λ = 500 nm, ε = 53 800 M–1 cm–1. The very high efficiency of emission achieved can be traced to an unusually high rate constant for the T1 → S0 phosphorescence process, allowing it to compete effectively with nonradiative vibrational decay. The high radiative rate constant correlates with an unusually large zero-field splitting of the triplet state, which is estimated to be 40 cm–1 by means of variable-temperature time-resolved spectroscopy over the range 1.7 < T < 120 K. The compound has been successfully tested as a red phosphor in an organic light-emitting diode prepared by solution processing. The results highlight a potentially attractive way to develop highly efficient red and NIR-emitting devices through the use of multinuclear complexes.
Item Type: | Article |
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Uncontrolled Keywords: | electroluminescence, near-infrared emission, deep-red luminescence, triplet harvesting, dinuclear platinum complex |
Subjects: | F200 Materials Science |
Department: | Faculties > Health and Life Sciences > Applied Sciences |
Depositing User: | Elena Carlaw |
Date Deposited: | 01 Mar 2019 16:34 |
Last Modified: | 10 Oct 2019 21:15 |
URI: | http://nrl.northumbria.ac.uk/id/eprint/38266 |
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