Electron transport engineering in photon-enhanced thermionic energy converters
Abstract/Contents
- Abstract
- A new physical mechanism for direct conversion of solar energy to electricity, called photon-enhanced thermionic emission (PETE), has attracted significant attention as a technology with the promise of very high power conversion efficiencies. The PETE mechanism involves thermionic emission of photoexcited electrons from a high temperature semiconductor cathode, followed by collection at a lower temperature, low work function anode. Due to its combination of photovoltaic and thermal processes, PETE has the potential to achieve efficiencies far above the fundamental limits for single-junction photovoltaics. In this work, two approaches to engineering electron transport in PETE energy converters are presented. A triode device with an electron-transparent gate electrode can be used to overcome space charge limitations that may reduce PETE converter efficiency. Graphene is considered as a candidate gate material, and SEM-based experimental measurements of its transparency to low energy (down to ~5 eV) electrons are reported. Even with an effective gate, the PETE process requires emission of electrons into vacuum, posing significant challenges to realizing efficient converters. To overcome this challenge, a solid-state PETE device structure is proposed, in which the vacuum gap is replaced by semiconductor nanowires that bridge the electrodes. These nanowires provide a path for electron transport while minimizing thermal conduction between the electrodes. Theoretical efficiencies for this device architecture are reported, and the implications of these results for realizing solid-state PETE converters are discussed.
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 | Rosenthal, Samuel James |
|---|---|
| Associated with | Stanford University, Department of Materials Science and Engineering. |
| Primary advisor | Melosh, Nicholas A |
| Thesis advisor | Melosh, Nicholas A |
| Thesis advisor | Howe, Roger Thomas |
| Thesis advisor | Salleo, Alberto |
| Advisor | Howe, Roger Thomas |
| Advisor | Salleo, Alberto |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Samuel James Rosenthal. |
|---|---|
| Note | Submitted to the Department of Materials Science and Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2016. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2016 by Samuel James Rosenthal
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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