Fundamental and applied studies of organic photovoltaic systems

Simple item page
dc.contributorBakker, Martin G.
dc.contributorSzulczewski, Gregory J.
dc.contributorBonizzoni, Marco
dc.contributorKung, Patrick
dc.contributor.advisorPan, Shanlin
dc.contributor.authorHill, Caleb M.
dc.contributor.otherUniversity of Alabama Tuscaloosa
dc.date.accessioned2017-03-01T17:09:49Z
dc.date.available2017-03-01T17:09:49Z
dc.date.issued2014
dc.descriptionElectronic Thesis or Dissertationen_US
dc.description.abstractPresented here are applied and fundamental studies of model organic photovoltaic (OPV) systems. Graphene oxide (GO) nanosheets were investigated as a potential electron acceptor in bulk heterojunction organic solar cells which employed poly[3-hexylthiophene] (P3HT) as an electron donor. GO nanosheets were transferred into organic solution through a surfactant-assisted phase transfer method. Electron transfer from P3HT to GO in solutions and thin films was established through fluorescence spectroscopy. Bulk heterojunction solar cells containing P3HT, P3HT-GO, and P3HT-phenyl-C<sub>61</sub>-butyric acid methyl ester (PCBM, a prototypical elector acceptor employed in polymer solar cells) were constructed and evaluated. Single molecule fluorescence spectroscopy was employed to study charge transfer between conjugated polymers and TiO<sub>2</sub> at the single molecule level. The fluorescence of individual chains of the conjugated polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) at TiO<sub>2</sub> surfaces was shown to exhibit increased intermittent (on/off "blinking") behavior compared to molecules on glass substrates. Single molecule fluorescence excitation anisotropy measurements showed the conformation of the polymer molecules did not differ appreciably between glass and TiO<sub>2</sub> substrates. The similarities in molecular conformation suggest that the observed differences in blinking activity are due to charge transfer between MEH-PPV and TiO<sub>2</sub>, which provides additional pathways between states of high and low fluorescence quantum efficiency. The electrodeposition of individual Ag nanoparticles (NPs), which can be used to enhance light harvesting in organic photovoltaic systems, was studied <italic>in situ</italic> via dark field scattering (DFS) microscopy. The scattering at the surface of an indium tin oxide (ITO) working electrode was measured during a potential sweep. Utilizing Mie scattering theory and high resolution scanning electron microscopy (SEM), the scattering data were used to calculate current-potential curves depicting the electrodeposition of individual Ag NPs. The oxidation of individual presynthesized and electrodeposited Ag NPs was also investigated using fluorescence and DFS microscopies.en_US
dc.format.extent207 p.
dc.format.mediumelectronic
dc.format.mimetypeapplication/pdf
dc.identifier.otheru0015_0000001_0001650
dc.identifier.otherHill_alatus_0004D_12079
dc.identifier.urihttps://ir.ua.edu/handle/123456789/2103
dc.languageEnglish
dc.language.isoen_US
dc.publisherUniversity of Alabama Libraries
dc.relation.hasversionborn digital
dc.relation.ispartofThe University of Alabama Electronic Theses and Dissertations
dc.relation.ispartofThe University of Alabama Libraries Digital Collections
dc.rightsAll rights reserved by the author unless otherwise indicated.en_US
dc.subjectPhysical chemistry
dc.subjectAnalytical chemistry
dc.subjectMaterials science
dc.titleFundamental and applied studies of organic photovoltaic systemsen_US
dc.typethesis
dc.typetext
etdms.degree.departmentUniversity of Alabama. Department of Chemistry
etdms.degree.disciplineChemistry
etdms.degree.grantorThe University of Alabama
etdms.degree.leveldoctoral
etdms.degree.namePh.D.

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
file_1.pdf
Size:
16.61 MB
Format:
Adobe Portable Document Format
Download

Collections

Theses and Dissertations
Theses and Dissertations - Department of Chemistry & Biochemistry