Charge transport in semiconducting polymers : connecting microstructure to electronic properties

Placeholder Show Content

Abstract/Contents

Abstract
Organic semiconductors have emerged as an alternative to conventional silicon-based electronics in a number of large-area applications including lighting, displays, and sensors. Their ease of processing and compatibility with solution-based deposition techniques makes them attractive for low-cost, roll-to-roll production processes. However, despite significant progress in recent years, the electronic performance of these materials remains modest relative to silicon, limiting their potential applications. In order for organic semiconductors to truly flourish in industry, electronic figures of merit such as charge carrier mobility must be improved further. The material microstructure is one of the key determinants of charge carrier mobility in organic semiconductors. While many new microstructure characterization tools have been developed and our understanding of the relationship between microstructure and electronic properties has greatly improved, significant questions remain, limiting our ability to rationally design and process new materials with improved performance. The focus of this dissertation has been in attempting to improve this understanding. In this dissertation, I discuss several ways in which the microstructure of semiconducting polymers affects their electronic properties. First, I present a procedure for determining the precise thin-film structure of a semiconducting polymer using two-dimensional grazing incidence X-ray diffraction. These packing structures can then be used in a variety of electronic structure calculations. Next, I discuss the role of molecular weight distribution as well as the impact of film confinement on the microstructure and electronic properties of two semicrystalline polythiophenes. I show how disorder, crystallinity, and chain orientation are strongly influenced by these factors and quantify their impact on charge carrier mobility. Finally, I describe our latest understanding of the factors governing charge transport in state-of-the-art materials. I suggest that disorder is an inextricable feature of semiconducting polymers that need not be highly detrimental to charge transport if it is embraced and planned for by designing materials which are resilient to this disorder.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2015
Issuance monographic
Language English

Creators/Contributors

Associated with Himmelberger, Scott
Associated with Stanford University, Department of Materials Science and Engineering.
Primary advisor Salleo, Alberto
Thesis advisor Salleo, Alberto
Thesis advisor McGehee, Michael
Thesis advisor Toney, Michael Folsom
Advisor McGehee, Michael
Advisor Toney, Michael Folsom

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Scott Himmelberger.
Note Submitted to the Department of Materials Science and Engineering.
Thesis Thesis (Ph.D.)--Stanford University, 2015.
Location electronic resource

Access conditions

Copyright
© 2015 by Scott Himmelberger
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

Also listed in

Loading usage metrics...