ИСТИНА

Organic molecules used in OLED devices (1st fluorescent, 2nd phosphorescent or 3rd TADF generations) consist of a large number of atoms, are flexible and, as a result, their properties are highly dependent on the environment. On the other hand, explicit quantum mechanical treatment of the environment of the active center is prohibitively expensive. Also, the available polarizable continuum models (PCMs) do not provide any reliable description of inhomogeneous environment. However, the multiscale approach allows high accuracy calculations of various properties for these compounds without requiring huge computational resources. In this work, the structures of the dopants with host or exciplexes, formed at interfaces, with its environment were generated using molecular dynamics. The spectra of the dopants or exciplexes were calculated using TD-DFT method. The environment of the chromophores was modelled as a QM/MM approach (Fig. 1a), and as effective fragment potentials (EFP) method (Fig. 2a). It was found that EFP provides the best description of the environment, making it possible to include both structural effects and molecular polarizability.