Lowbandgap 2017

Grenzflächeneigenschaften und elektronische Struktur von neuen organischen Low-Bandgap Materialien

01/10/2017 to 30/09/2020

Low band gap (LBG) polymers are promising candidates for active
organic layers in opto-electronic devices, such as organic solar cells
or light emitting diodes. The properties of these materials in devices
are strongly influenced by their morphology and ability for selforganization
in thin-films. It was already shown within the first funding
period that (additional) alkyl-thiophene moieties can improve distinctly
film forming properties in thin films of LBG polymers. A systematic
investigation of the influence of the introduction of thienylene spacer
units with different substitution pattern in LBG polymer structures on
both electronic properties and the ability for self-organization is the
first goal of this proposal. The second focus of the joint project is the
synthesis and characterization of new diketopyrrolopyrrole (DPP)-
based donor-acceptor co-polymers with a varying degree of
ladderization. We will investigate how the degree of
planarization/ladderization influences the ordering and electronic
properties in thin films. The experimental investigations of thin films
and interfaces will be carried out using a variety of complementary
spectroscopic and microscopic techniques that shall provide wide and
detailed information on both (interfacial) electronic structure and
organization in thin films. That includes photoemission and various
optical spectroscopies in addition to atomic force and electron
microscopy.