ABSTRACT
Ladungstransportstudien an realistischen, organischen Halbleitersystemen: Theoretische Modellierung von Experimenten zur Etablierung von in silico Materialdesign
Sebastian Radke, Technische Universität Dresden
In a theoretical study combining molecular dynamics simulations,quantum-chemical calculations, and Marcus theory-based charge migration
simulations, I investigate the electronic structure and the charge transport of
three members of a promising class of organic near-infrared absorber materials:
aza-BODIPYs, which are partially already successfully used as the donor material
in organic solar cells.[1] The local character of the frontier molecular
orbitals and their coupling to the intramolecular dynamics significantly
influence the size of the total charge carrier mobility and determine whether a
material has a higher electron or hole conductance. These effects depend also on
the molecular packing and correspondingly on steric effects causing differences
in the ratio between the electron and the hole mobility of highly ordered
materials. Interestingly, the fluctuations of the transfer integrals
can influence both the total value of the charge carrier mobility as well as
its anisotropy. This demonstrates that both local and non-local energetic
disorder effects have to be considered to formulate design rules for the class
of aza-BODIPY derivatives to help to further improve the
efficiency of organic solar cells.
[1] T. Mueller et al. Solar Energy Materials & Solar Cells 99, 176-181 (2012).
