Universität zu Köln

Gildemeister, Nora ORCID: 0009-0004-6779-0251 (2024). Modelling Charge Transport across Regimes in Merocyanine Single Crystals. PhD thesis, Universität zu Köln.

PDF Dissertation_Nora_Gildemeister_Feb_2024.pdf Download (26MB)

Abstract

Merocyanines are highly dipolar pi-conjugated molecules, consisting of electronic donor (D) and acceptor (A) subunits connected via a methine bridge. They exhibit unique self-assembly and tuneable opto-electronic properties, making them optimal active materials for organic electronic applications. Recent experiments on single-crystal OFETs revealed hole mobilities up to 2 cm²V⁻¹s⁻¹, setting them on a competitive stage with respect to other organic semiconductors. Charge transport properties of various merocyanines have been investigated, encompassing different donor acceptor moieties with varying lateral groups, resulting in different crystal packing, and clear structure-property relationships have been drawn. Furthermore, different levels of theory across various transport regimes have been merged, ranging from non-adiabatic (hopping) transport to intermediate polaron transfer. Within the non-adiabatic regime, the impact of static (electrostatic and polarization effects) and thermal (electron-phonon coupling) disorder have been modelled and rationalised in details, thus providing a unified description of hole transport in merocyanine single crystals. Overall this is the first computational investigation modelling all aspects concerning charge transport, from intra- to intermolecular properties for the class of merocyanines, as well as modelling charge transport across regimes, while analysing the impact of static and thermal disorder effects.

Item Type:	Thesis (PhD thesis)
Creators:	Creators Email ORCID ORCID Put Code Gildemeister, Nora gildemeisternora@yahoo.de orcid.org/0009-0004-6779-0251 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-744242
Date:	2024
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Chemistry > Institute of Physical Chemistry
Subjects:	Chemistry and allied sciences
Uncontrolled Keywords:	Keywords Language charge transport, organic semiconductors, merocyanine, hopping transport, organic electronics, computational chemistry, hole transport material English
Date of oral exam:	10 April 2024
Referee:	Name Academic Title Meerholz, Klaus Professor Engels, Bernd Professor
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/74424