Better together : composite plasmonic materials for enhaced upconversion and responsive metasurfaces
Abstract/Contents
- Abstract
- Composites can combine the best qualities of multiple materials. In some cases, composite materials can exhibit properties that improve upon their components -- forming a material that is greater than the sum of its parts. In this dissertation, we examine two materials systems wherein combining multiple materials at the nanoscale enhances the resultant properties. We begin by studying upconversion, the conversion of photons from lower to higher energies. Upconversion is a process that promises applications ranging from high-efficiency photovoltaic and photocatalytic cells to background-free bioimaging and therapeutic probes. Existing upconverting materials, however, remain too inefficient for viable implementation. Here, we describe the significant improvements in upconversion efficiency that can be achieved by combining upconverting materials with metallic nanostructures. We review both theoretical underpinnings and experimental demonstrations of plasmon-enhanced upconversion, and elucidate design strategies for optimal enhancements. Then, we demonstrate how plasmonic materials can add new function to upconverting materials by making a transparent upconverting electrode which enhances upconversion emission by 4x. Next, we consider optical materials with dynamic refractive index. Such materials could be transformative, enabling active camouflage, tunable holograms, and novel colorimetric medical sensors. We draw inspiration from chameleons and cephalopods, experts at changing their color, pattern, and reflectivity in response to their environment. Here, we demonstrate a chemically tunable, large-area metasurface with a strong magnetic response. By combining plasmonic nanoantennas with an elastomeric substrate, we can reversibly tune the material's refractive index from positive to negative values. Such a material may provide a new path towards programmable optical elements and responsive light routing.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2016 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Wu, Di Meng |
|---|---|
| Associated with | Stanford University, Department of Chemistry. |
| Primary advisor | Dionne, Jennifer Anne |
| Primary advisor | Salleo, Alberto |
| Thesis advisor | Dionne, Jennifer Anne |
| Thesis advisor | Salleo, Alberto |
| Thesis advisor | Kanan, Matthew William, 1978- |
| Advisor | Kanan, Matthew William, 1978- |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Di Meng Wu. |
|---|---|
| Note | Submitted to the Department of Chemistry. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2016. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2016 by Di Meng Wu
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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