Understanding structure-property relationships in thermoelectric materials
Abstract/Contents
- Abstract
- Thermoelectric materials have the ability to convert thermal energy into electrical energy. Successful development of thermoelectric technologies could have a significant impact on the current energy landscape, where much of the energy consumed is wasted as low-grade heat. However, progress in increasing the efficiency of thermoelectric materials has been hampered by the difficulty of optimizing competing material properties, such as thermal conductivity, electrical conductivity, and carrier concentration. Each of these properties is fundamentally driven by the underlying material structure, with defects and dopants playing an especially important role. So in order to optimize a material's thermoelectric properties, it is first necessary to understand the material's crystal structure. In this work, I focus on understanding the structure-property relationships in a specific thermoelectric alloy material, Cu2xHg2−xGeTe4, which has proven to be an interesting case study in the field of thermoelectrics. To analyze the structure side of the structure-property relationship, I have primarily relied on the use of a technique known as resonant energy X-ray diffraction to provide a holistic view of the material structure and to quantify the presence of anti-site defects. Cu-Hg anti-site defects are found to be the dominating force in controlling the material's carrier concentration. The effect of these Cu-Hg anti-site defects is also explored using inelastic neutron scattering, which provides insight on the phonon density of states of a material. The results indicate that Cu-Hg anti-site defects not only control the carrier concentration of Cu2xHg2−xGeTe4, but also impact the behavior of phonon dynamics within the system. In turn, this has implications on other relevant thermoelectric properties, such as the lattice thermal conductivity. The findings and processes established in this dissertation can contribute to future efforts for characterizing structure-property relationships, not only in the field of thermoelectrics, but for semiconductors in general.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2022; ©2022 |
| Publication date | 2022; 2022 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Levy-Wendt, Benjamin Louis |
|---|---|
| Degree supervisor | Toney, Michael Folsom |
| Degree supervisor | Zheng, Xiaolin, 1978- |
| Thesis advisor | Toney, Michael Folsom |
| Thesis advisor | Zheng, Xiaolin, 1978- |
| Thesis advisor | Kenny, Thomas William |
| Degree committee member | Kenny, Thomas William |
| Associated with | Stanford University, Department of Mechanical Engineering |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Benjamin Louis Levy-Wendt. |
|---|---|
| Note | Submitted to the Department of Mechanical Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2022. |
| Location | https://purl.stanford.edu/bn787qf3254 |
Access conditions
- Copyright
- © 2022 by Benjamin Louis Levy-Wendt
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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