Alexandria Digital Research Library

Structure-Property Relationships in Semiconducting Polymers and Small Molecules Probed by Synchrotron X-ray Methods

Author:
Su, Gregory M.
Degree Grantor:
University of California, Santa Barbara. Materials
Degree Supervisor:
Michael L. Chabinyc
Place of Publication:
[Santa Barbara, Calif.]
Publisher:
University of California, Santa Barbara
Creation Date:
2015
Issued Date:
2015
Topics:
Materials science and Polymer chemistry
Keywords:
Synchrotron
Polymer
Organic semiconductors
Morphology
X-ray scattering
X-ray absorption spectroscopy
Genres:
Online resources and Dissertations, Academic
Dissertation:
Ph.D.--University of California, Santa Barbara, 2015
Description:

Organic semiconductors are an exciting class of materials that have potential to produce low-cost, printable, and flexible electronic devices. Moving to the next generation of organic semiconductors that will result in greater efficiency requires advancements in the areas of materials chemistry, molecular assembly, predictive modelling, and device optimization. Here, we focus on morphology and demonstrate how it is linked to each of these areas. Understanding the connections among chemistry, thin film microstructure, and charge transport remains a major challenge in the field. We examined materials systems relevant to organic solar cells, memory devices, and transistors, with a focus on synchrotron-based X-ray techniques. For a blend of a polymer and small molecule, applicable to solar cells, control of molecular orientation in the small molecule is especially important for non-fullerene based molecules that exhibit anisotropic charge transport. In ferroelectric-semiconductor polymer blends used in organic memory, improved control over phase separation length scales is achieved by altering the chemistry of the semiconducting polymer to tune polymer-polymer interactions. Complementary simulations can facilitate characterization of organic semiconductors. First-principles predictions of X-ray absorption spectroscopy are applied to semiconducting polymers, and prove critical for understanding complex experimental data related to molecular orientation and electronic structure in general. Overall, these studies provide insights into key factors that should be considered in the development of new organic semiconductors.

Physical Description:
1 online resource (174 pages)
Format:
Text
Collection(s):
UCSB electronic theses and dissertations
ARK:
ark:/48907/f3pg1r8w
ISBN:
9781339472140
Catalog System Number:
990046180200203776
Rights:
Inc.icon only.dark In Copyright
Copyright Holder:
Gregory Su
File Description
Access: Public access
Su_ucsb_0035D_12837.pdf pdf (Portable Document Format)