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

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.

4 pages, 4 figues

Cited by in corpus (1)

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