Dynamic Effects on Hole Transport in Amorphous Organic Semiconductors: a Combined QM/MM and kMC Study.

Small-molecule-based amorphous organic semiconductors (OSCs) are essential components of organic photovoltaics and organic light-emitting diodes. The charge carrier mobility of these materials is an integral and limiting factor in regard to their performance. Integrated computational models for the hole mobility, taking into account structural disorder in systems of several thousand molecules, have been the object of research in the past.

Understanding excited state properties of host materials in OLEDs: simulation of absorption spectrum of amorphous 4,4-bis(carbazol-9-yl)-2,2-biphenyl (CBP).

4,4-Bis(carbazol-9-yl)-2,2-biphenyl (CBP) is widely used as a host material in phosphorescent organic light-emitting diodes (PhOLEDs). In the present study, we simulate the absorption spectra of CBP in gas and condensed phases, respectively, using the efficient time-dependent long-range corrected tight-binding density functional theory (TD-LC-DFTB). The accuracy of the condensed-phase absorption spectra computed using the structures obtained from classical molecular dynamics (MD) and quantum mechanical/molecular mechanical (QM/MM) simulations is examined by comparison with the experimental absorption spectrum.