"SPECIAL CONDENSED MATTER SEMINAR: Challenges for in-silico design of organic semiconductors"

 

 

ABSTRACT:

 

The evaluation of organic materials for use in electronic devices relies on unraveling the dynamics of excitations in realistic morphologies. 

Following the link from molecular electronic structure via local and global morphology to device-scale properties, e.g. charge mobility, is the key challenge for the in-silico design of organic semiconductors [1]. Zooming in on the behavior of electrons and molecules and bridging
micro- and macroscopic worlds can be achieved using multiscale simulation schemes that combine electronic structure theory with classical molecular dynamics approaches and kinetic Monte-Carlo simulations.

 

In this talk, I will give an overview of the multiscale methodology used in our modeling approach as implemented in the VOTCA software [2]. The workflow will be illustrated for the case of a prototypical small-molecule organic solar cell formed from acceptor-substituted
oligothiophenes and C60 [3]. This will also allow me to highlight the challenges such methods face when aiming at quantitative predictions, such as an accurate description of electron-hole pair excitations [4], the proper treatment of long-range electrostatics, or size-limitations [5].

 

[1] Baumeier, May, Lennartz, Andrienko, J. Mater. Chem. 22, 10971-10976 (2012).

[2] Ruehle, Lukyanov, May, Schrader, Vehoff, Kirkpatrick, Baumeier, Andrienko, J. Chem. Theory Comput. 7, 3335-3345 (2011).

[3] Fitzner et al., Adv. Func. Mater 21, 897-910 (2011). 

[4] Baumeier, Andrienko, Rohlfing, J. Chem. Theory Comput. 8, 2790 (2012).

[5] Baumeier, Stenzel, Poelking, Andrienko, Schmidt, Phys. Rev. B 86, 184202 (2012).