Kolloquien
URL zum ICS-Kalender dieses Seminars
Kirchhoff-Institut für Physik, Otto-Haxel-Hörsaal
freitags 17:15
Vorträge
5.11.2021 17:00
INF 308, Hörsaal 1
Man-made organic materials allow to tailor functional device properties in an
unprecedented manner. A prerequisite is the fundamental understanding of the
underlying physics. In this seminar, I will introduce some of our recent work, in which
we investigate the fundamentals of charge motion in carbon-based molecular materials
and use the gained insights to develop novel electronic functionality. Examples will
include ongoing work on organic solar cells, where I will show how far-from-equilibrium
phenomena can be used to make major improvements to device characteristics,
including power conversion efficiency. Another research direction that I will touch upon
are hybrid semiconducting-dipolar materials that show a strong coupling between
ferroelectric polarization and conductivity, that might find application in conventional or
neuromorphic memories. The figure shows the design principle of this type of material:
a planar molecule with a pi-conjugated core (here a simple benzene ring) and dipolar
moieties (here amides) forms helical stacks that are stabilized through hydrogen
bonding. The hexagonal packing of multiple stacks in a thin-film geometry results in a
material with a bistable electrical polarization that can be flipped by an external electric
field. Charge transport along and against the polarization are not equivalent, leading
to resistance differences.