Development of conjugated materials for organic electronics applications
File(s)
Author(s)
Rimmele, Martina
Type
Thesis
Abstract
Organic semiconductors, comprised of carbon-containing compounds, are vital in electronics, notably in applications like organic solar cells, OLEDs, and OFETs due to their flexibility and lightweight nature. Synthesising these materials is complex due to varied chemical structures, demanding precise control over molecular architecture to achieve desired electronic properties.
This thesis explores simple methods for preparing polymer systems for organic electronics, focusing on a two-step protocol from benzo[c][1,2,5]thiadiazole, yielding eleven polymers which properties were studied. Looking into the influence small structural changes have on the characteristics of the materials, we also investigated the photovoltaic properties. One donor emerged as especially high performing in organic photovoltaics, namely FO6-T, and this led to further investigations into this structure. By changing the acceptor unit in the donor-acceptor structure of the polymer, incorporating different heteroatoms, changes on the polymer properties and investigating organic photodetectors and organic field effect transistor devices were explored.
The investigation also delves into altering polymer properties through post-polymerisation functionalisation. Efficient and selective reactions are crucial to prevent complex mixtures or permanent defects. Three graft copolymers with poly(styrene) were prepared, and their optical properties were explored.
Additionally, the study examines conjugated macrocycles, highlighting their intriguing optoelectronic properties and intermolecular interactions. A series of macrocycles with varying electron densities were prepared, revealing intriguing effects on crystal structure. Overall, this research contributes to understanding and enhancing the properties of organic semiconductors through tailored synthesis methods and exploration of diverse molecular architectures.
This thesis explores simple methods for preparing polymer systems for organic electronics, focusing on a two-step protocol from benzo[c][1,2,5]thiadiazole, yielding eleven polymers which properties were studied. Looking into the influence small structural changes have on the characteristics of the materials, we also investigated the photovoltaic properties. One donor emerged as especially high performing in organic photovoltaics, namely FO6-T, and this led to further investigations into this structure. By changing the acceptor unit in the donor-acceptor structure of the polymer, incorporating different heteroatoms, changes on the polymer properties and investigating organic photodetectors and organic field effect transistor devices were explored.
The investigation also delves into altering polymer properties through post-polymerisation functionalisation. Efficient and selective reactions are crucial to prevent complex mixtures or permanent defects. Three graft copolymers with poly(styrene) were prepared, and their optical properties were explored.
Additionally, the study examines conjugated macrocycles, highlighting their intriguing optoelectronic properties and intermolecular interactions. A series of macrocycles with varying electron densities were prepared, revealing intriguing effects on crystal structure. Overall, this research contributes to understanding and enhancing the properties of organic semiconductors through tailored synthesis methods and exploration of diverse molecular architectures.
Version
Open Access
Date Issued
2023-12-07
Date Awarded
01/03/2024
License URL
Advisor
Heeney, Martin
Sponsor
Engineering and Physical Sciences Research Council
Grant Number
EP/R513052/1
Publisher Department
Chemistry
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)