dc.contributor.advisor |
Wong, Cathy |
|
dc.contributor.author |
Crawford, Michael |
|
dc.date.accessioned |
2022-10-26T17:07:09Z |
|
dc.date.issued |
2022-10-26 |
|
dc.identifier.uri |
https://scholarsbank.uoregon.edu/xmlui/handle/1794/27780 |
|
dc.description.abstract |
Nanocrystals (NCs) of mixed-halide perovskite materials offer great potential for solar cells and light-emitting devices owing to their unusual defect tolerance and the tunability of their bandgap via size and halide composition. However, widespread adoption of these mixed-halide perovskite materials is prevented by bandgap instability due to segregation of the halides upon exposure to light or electrical current. This segregation creates regions with a narrower bandgap than the well-mixed phase, redshifting the emission spectrum. In this work I describe efforts to prevent this process by chemical treatment of methylammonium lead iodide-bromide (MAPbIxBr3−x) NCs using a mixture of small, stronglybinding ligands. I use transient absorption (TA) spectroscopy to collect dynamics information during halide segregation, informing a computational model used to extract mechanistic information about the halide segregation process. Using this model, I determine that the observed spectroscopic trends are best explained by iodide anions preferentially segregating into a region within the NC, rather than directly toward the NC surface. The mechanistic insight provided by this work will contribute to future approaches to stabilizing the bandgap in mixed-halide perovskite NCs. |
en_US |
dc.language.iso |
en_US |
|
dc.publisher |
University of Oregon |
|
dc.rights |
All Rights Reserved. |
|
dc.subject |
Core-Shell Heterostructure |
en_US |
dc.subject |
Global Fitting Analysis |
en_US |
dc.subject |
Halide Segregation |
en_US |
dc.subject |
Nanocrystal |
en_US |
dc.subject |
Perovskite |
en_US |
dc.subject |
Transient Absorption |
en_US |
dc.title |
Influencing Halide Segregation in Perovskite Nanocrystals via Surface Treatment |
|
dc.type |
Electronic Thesis or Dissertation |
|
dc.description.embargo |
2023-04-17 |
|
thesis.degree.name |
Ph.D. |
|
thesis.degree.level |
doctoral |
|
thesis.degree.discipline |
Department of Chemistry and Biochemistry |
|
thesis.degree.grantor |
University of Oregon |
|