# Multiscale Simulation of Photoluminescence Quenching in Phosphorescent OLED Materials [in press]

Symalla, Franz; Heidrich, Shahriar; Friederich, Pascal; Strunk, Timo; Neumann, Tobias; Minami, Daiki; Jeong, Daun; Wenzel, Wolfgang

##### Abstract:
Bimolecular exciton-quenching processes such as triplet–triplet annihilation (TTA) and triplet–polaron quenching play a central role in phosphorescent organic light-emitting diode (PhOLED) device performance and are, therefore, an essential component in computational models. However, the experiments necessary to determine microscopic parameters underlying such processes are complex and the interpretation of their results is not straightforward. Here, a multiscale simulation protocol to treat TTA is presented, in which microscopic parameters are computed with ab initio electronic structure methods. With this protocol, virtual photoluminescence experiments are performed on a prototypical PhOLED emission material consisting of 93 wt% of 4,4ʹ,4ʺ-tris(N-carbazolyl)triphenylamine and 7 wt% of the green phosphorescent dye fac-tris(2-phenylpyridine)iridium. A phenomenological TTA quenching rate of 8.5 × 10$^{-12}$ cm$^{3}$ s$^{-1}$, independent of illumination intensity, is obtained. This value is comparable to experimental results in the low-intensity limit but differs from experimental rates at higher intensities. This discrepancy is attributed to the difficulties in accounting for fast bimolecular quenching during exciton generation in the interpretation of experimental data. ... mehr

 Zugehörige Institution(en) am KIT Institut für Nanotechnologie (INT) Publikationstyp Zeitschriftenaufsatz Publikationsjahr 2020 Sprache Englisch Identifikator ISSN: 2513-0390, 2513-0390 KITopen-ID: 1000117693 Erschienen in Advanced theory and simulations Seiten 1900222 Vorab online veröffentlicht am 24.02.2020 Nachgewiesen in Web of Science
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