Towards Self-assembling Multichromophoric Materials for Organic Semiconductors
Abstract
Organic semiconductors are generally lightweight, flexible materials that can be solution processed. These properties make them an economical alternative to inorganic semiconductors, as they can be more easily manufactured and integrated into existing infrastructure. However, organic electronic devices have seen only marginal improvements in charge carrying ability over the last few decades due to a compromise between ease of manufacturing and efficient charge transport.
The field of organic electronics has been developing new molecular systems with attention to the electronic properties of the individual molecules, in addition to understanding the self-assembly of these molecules in the solid state. The goal of this thesis was to investigate the molecular and supramolecular properties of novel multichromophoric molecules as organic semiconductors, which could be an alternative to the bimolecular systems that are commonly used in electronic devices.
First, phenothiazine derivatives were synthesized and optical and electrochemical properties were studied as potential electron donor chromophores. These phenothiazine derivatives were found to have large Stokes shifts associated with a large geometry change upon excitation.
Second, analogous acridone derivatives were synthesized and investigated to explore the differences in optical properties. They did not exhibit a large geometry change upon excitation but underwent intramolecular charge transfer, enhancing the absorption properties compared to phenothiazine.
Lastly, a multichromophoric triad comprised of a naphthalene diimide core flanked by two phenothiazine derivatives separated by an alkyl spacer was synthesized. The optical and electrochemical properties of the triad in solution were investigated as well as self-assembly and photocurrent responses in films. It was demonstrated that the chromophores in the triad behaved independently both optically and electrochemically. In the solid state, the triad formed ordered films and generated small currents upon exposure to light, which are encouraging preliminary results towards the development of new multichromophoric photoactive materials.
Description
Keywords
Chemistry--Organic
Citation
Thériault, K. (2016). Towards Self-assembling Multichromophoric Materials for Organic Semiconductors (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/28487