Computer Simulation of Charge Transport in Organic Semiconductors

Prof. Jochen Blumberger (JB, University College London, Department of Physics and Astronomy) has been a Hans Fischer Fellow. With his host Prof. Karsten Reuter (KR, TUM Department of Chemistry), co-host Prof. Peter Mueller-Buschbaum (PMB, TUM Department of Physics) and TUM-IAS sponsored PhD student Patrick Gütlein, he was developing and applying a novel computer programme for the simulation of charge carrier transport in materials for organic electronics and solar cells.

The central methodological aim was the development of a fast but predictive non-adiabatic molecular dynamics (NAMD) approach which will enable new fundamental insight into the nature of charge carrier transport (CT) in organic semiconductor (OS) materials. This joint investigation will benefit from the complementary know-how of JB and KR that precisely spans the range of techniques required to advance such an approach, namely JB’s expertise in the molecular computation of electron transfer reactions and that of KR’s group in the multi-scale modelling of processes from the electronic to the mesoscale. The new implementation is designed to access length and time scales unreachable with existing NAMD methods, and will so open the door for ground breaking new insight into the charge transport mechanism and open up calculations on large application-relevant systems.

The latter capability will be directly exploited in the close collaboration with PMB and his group, who has world-leading expertise in the fabrication and characterization of OS materials for use in OPV devices. Together with PMB we will investigate structure-charge transport relationships in OS. By combining theory and experiment, we would like to understand how the solid state structure, specifically crystal packing and the presence of defects and interfaces between crystalline and amorphous domains affect the charge transport in these materials. Here, a molecular scale understanding of the electronic processes that happen at organic interfaces is crucial to inform the engineering of high performance OS, and ultimately the fabrication of next-generation OPV cells with unprecedented efficiencies.

TUM-IAS funded doctoral candidate:
Patrick Gütlein, TUM Department of Chemistry