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arXiv · 1209.3703

Role of electronic localization in the phosphorescence of iridium sensitizing dyes

Burak Himmetoglu·Alex Marchenko·Ismaila Dabo·Matteo Cococcioni
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Abstract

In this work we present a systematic study of three representative iridium dyes, namely, Ir(ppy)3, FIrpic and PQIr, which are commonly used as sensitizers in organic optoelectronic devices. We show that electronic correlations play a crucial role in determining the excited-state energies in these systems, due to localization of electrons on Ir d orbitals. Electronic localization is captured by employing hybrid functionals within time-dependent density-functional theory (TDDFT) and with Hubbard-model corrections within the delta-SCF approach. The performance of both methods are studied comparatively and shown to be in good agreement with experiment. The Hubbard-corrected functionals provide further insight into the localization of electrons and on the charge-transfer character of excited-states. The gained insight allows us to comment on envisioned functionalization strategies to improve the performance of these systems. Complementary discussions on the delta-SCF method are also presented in order to fill some of the gaps in the literature.

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Burak Himmetoglu, Alex Marchenko, Ismaila Dabo, Matteo Cococcioni. 2012-09-17. Role of electronic localization in the phosphorescence of iridium sensitizing dyes. https://doi.org/10.1063/1.4757286

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