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Designing molecules to bypass the singlet-triplet bottleneck in the electroluminescence of organic light-emitting-diode materials

M. W. C. Dharma-wardana·Marek Z. Zgierski
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Abstract

Electroluminescence in organic light emitting diode (OLED) materials occurs via the recombination of excitonic electrons-hole pairs Only the singlet excitons of commonly used OLED materials, e.g., Aluminum trihydroxyquinoline (AlQ$_3$), decay radiatively, limiting the external quantum efficiency to a maximum 25%. Thus 75% of the energy is lost due to the triplet bottleneck for radiative recombination. We consider molecules derived from AlQ$_3$ which bypass the triplet bottleneck by designing structures which contain strong spin-orbit coupling. As a first stage of this work, groundstate energies and vertical excitation energies of Al-arsenoquinolines and Al-boroarsenoquinolines are calculated. It is found that the substitution of N by As leads to very favourable results, while the boron substitution leads to no advantage.

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M. W. C. Dharma-wardana, Marek Z. Zgierski. 2002-08-19. Designing molecules to bypass the singlet-triplet bottleneck in the electroluminescence of organic light-emitting-diode materials. https://doi.org/10.1088/1464-4258%2F4%2F6%2F367

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