Controlling light at the nanoscale for broadband metamaterials, efficient solar cells, and subwavelength 3D imaging
Abstract/Contents
- Abstract
- The iridescent wings of a butterfly, the vivid colors of a stained glass window, the mesmerizing rainbow in a soap bubble - all of these beautiful optical phenomena are made possible by the interaction of light with nanoscale materials. Beyond brilliant colors, rational control of the unique and often surprising ways in which light interacts with materials at extremely small length scales has enabled novel optical phenomena, devices, and characterization techniques. In this thesis, we discuss three such applications of nanophotonic engineering: metamaterials, solar cells, and nanoscale optical tomography. First, we describe the design of a metamaterial - a composite material with a tunable refractive index spanning positive, zero, and negative values - that operates over a broad spectral range. While metamaterials have made possible previously unthinkable phenomena including invisibility cloaking and sub-diffraction-limited imaging, designing a metamaterial with a broad operational bandwidth at visible frequencies is an outstanding challenge. Here we demonstrate theoretically a broadband metamaterial presenting negative indices across hundreds of nanometers in the visible and near-infrared, more than doubling previous record bandwidths. Second, we discuss optical methods for increasing photocurrent from solar cells by making use of low energy subbandgap photons. Upconversion - the process of converting low energy light to high energy light - promises to be an economical solution to this problem, but existing upconverting materials require substantial improvements to become viable. Here we describe the realistic improvements achievable with an upconverter enhanced solar cell and propose a nanophotonic system to improve the efficiency of the upconversion process itself. Last, we introduce a new method for probing light-matter interactions with nano\-meter scale resolution in three dimensions. Our technique, called cathodoluminescence tomography, extends sub-diffraction limited imaging from two to three spatial dimensions, while also revealing spectral information across visible and near infrared frequencies. This new imaging capability could be used, for example, to probe the distribution of defect states in photovoltaics, or locate recombination centers in light emitting diodes.
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 | Atre, Ashwin Alexander Coors |
|---|---|
| Associated with | Stanford University, Department of Materials Science and Engineering. |
| Primary advisor | Dionne, Jennifer Anne |
| Thesis advisor | Dionne, Jennifer Anne |
| Thesis advisor | Brongersma, Mark L |
| Thesis advisor | McGehee, Michael |
| Advisor | Brongersma, Mark L |
| Advisor | McGehee, Michael |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Ashwin Alexander Coors Atre. |
|---|---|
| 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 Ashwin C Atre
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