Manipulating light absorption in ultrathin semiconductor layers for optoelectronic applications
Abstract/Contents
- Abstract
- The achievement of strong light absorption in ultrathin layers of material has been of great scientific and practical interest for many years. The realization of ultra-thin strongly-absorbing layers can increase performance, reduce fabrication and materials cost of many thin-film optoelectronic device applications, including next generation solar cells, solar fuel generation and ultrathin photodetectors. In this thesis, we have demonstrated how to attain strong light absorption in the ultrathin layer of active materials in both theory and experiment. We have achieved this goal by harnessing two fundamentally different skills of light trapping based on the ray optics or wave optics. The first approach of ray optics utilizes geometric light traps that configure the substrate into the form of V groove and increase optical path length. We briefly mentioned this skill in chapter 2 by applying it to the organic solar cells to improve device efficiency. The second approach of wave optics relies on the resonance effect of nanostructure to concentrate light in the nano-scaled volume of material. We assembled these resonant building blocks into the form of array configuration to realize ultrathin strongly absorbing layer. The second approach is explained in most part of this thesis with detailed sub-skills. Specifically, we exhibited two different designing strategies for wave optics light trapping, the wavelength scaled design (in chapter 3) and the subwavelength scaled design (in chapter 4 & 5). We analyzed the two designing strategies in terms of their conceptual and physical differences and applied each to particular applications. The first designing strategy is applied to the solar fuel generation by nanostructuring photocatalysts materials to facilitate hydrogen generation rate. And the second strategy is demonstrated by designing germanium metafilm absorber for general optoelectronic applications. In addition to the specific examples demonstrated above, these light absorption methods can be used in the more general ultrathin optoelectronic applications such as diverse solar energy harvesting devices, photodetectors, and even light emitting devices by efficiently extracting light.
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 | Kim, Soo Jin |
|---|---|
| Associated with | Stanford University, Department of Electrical Engineering. |
| Primary advisor | Brongersma, Mark L |
| Thesis advisor | Brongersma, Mark L |
| Thesis advisor | Fan, Shanhui, 1972- |
| Thesis advisor | Miller, Dave A |
| Advisor | Fan, Shanhui, 1972- |
| Advisor | Miller, Dave A |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Soo Jin Kim. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2015. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2015 by Soo Jin Kim
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
Also listed in
Loading usage metrics...