De Novo Calculation of the Charge Carrier Mobility in Amorphous Small Molecule Organic Semiconductors

Simon Kaiser; Tobias Neumann; Franz Symalla; Tobias Schlöder; Artem Fediai; Pascal Friederich; Wolfgang Wenzel

doi:10.3389/fchem.2021.801589

De Novo Calculation of the Charge Carrier Mobility in Amorphous Small Molecule Organic Semiconductors

Front Chem. 2021 Dec 24:9:801589. doi: 10.3389/fchem.2021.801589. eCollection 2021.

Authors

Simon Kaiser¹, Tobias Neumann², Franz Symalla², Tobias Schlöder¹, Artem Fediai¹, Pascal Friederich^{1

3}, Wolfgang Wenzel¹

Affiliations

¹ Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
² Nanomatch GmbH, Karlsruhe, Germany.
³ Institute of Theoretical Informatics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.

Abstract

Organic semiconductors (OSC) are key components in applications such as organic photovoltaics, organic sensors, transistors and organic light emitting diodes (OLED). OSC devices, especially OLEDs, often consist of multiple layers comprising one or more species of organic molecules. The unique properties of each molecular species and their interaction determine charge transport in OSCs-a key factor for device performance. The small charge carrier mobility of OSCs compared to inorganic semiconductors remains a major limitation of OSC device performance. Virtual design can support experimental R&D towards accelerated R&D of OSC compounds with improved charge transport. Here we benchmark a de novo multiscale workflow to compute the charge carrier mobility solely on the basis of the molecular structure: We generate virtual models of OSC thin films with atomistic resolution, compute the electronic structure of molecules in the thin films using a quantum embedding procedure and simulate charge transport with kinetic Monte-Carlo protocol. We show that for 15 common amorphous OSC the computed zero-field and field-dependent mobility are in good agreement with experimental data, proving this approach to be an effective virtual design tool for OSC materials and devices.

Keywords: KMC; de novo; mobility; multiscale workflow; organic semiconductor.