Device engineering for efficient dye-sensitized solar cells
Abstract/Contents
- Abstract
- Dye-sensitized solar cells (DSCs) offer a variety of advantages to typical silicon and thin film solar cells. And while the advantages of ease-of-processing and fabrication from low-cost, earth-abundant materials make DSCs an attractive technology, the efficiency of DSCs (13%) is still too low to compete with the current inorganic incumbents. Hence, new 'outside-of-the-box' strategies must be used to render DSCs competitive with current commercial technologies. This thesis describes my work on identifying losses in DSCs and 2 strategies to improve the efficiency of DSCs: the use of highly-soluble energy relay days to broaden the spectral response of DSCs, and the fabrication of semi-transparent solid-state DSCs to help improve the efficiency of inorganic devices in a tandem solar cell. Solid-state dye-sensitized solar cells (ssDSCs) have historically lagged behind their liquid-electrolyte counterparts in efficiency. To gain a better understanding of why this is so, we have developed accurate internal quantum efficiency (IQE) measurements for ssDSCs. By analyzing the IQE, it is found that while charge collection is efficient in ssDSCs, often charge injection is not. This analysis also shows that parasitic absorption by the Spiro-OMeTAD is an important loss mechanism in ssDSCs and suggests that stronger absorbing sensitizers are the most promising path to higher efficiencies. In DSCs, the roles of absorbing light, injecting charge, and blocking recombination are all given to the sensitizing dye, resulting in a myriad of design rules for DSC sensitizers. An energy relay dye (ERD) is a second dye that helps relax these design rules by providing complementary absorption and then transferring energy to a sensitizing dye. However, such ERDs come with their own design rules, including the need for high solubility for full light absorption, and high photoluminescence for efficient energy transfer. We have designed and synthesized two such dyes, and characterized them as ERDs in DSCs, yielding a 65% increase in efficiency. Finally, even if DSCs are unable to reach efficiencies that render them competitive against traditional inorganic solar cells, DSCs can be used in conjunction with an inorganic solar cell in a hybrid tandem photovoltaic (HTPV). High open-circuit voltages and cheap processing render DSCs attractive top cells in HTPVs, and such devices can exceed efficiencies of 20%. However, in order to be used in HTPVs, a DSC must be fabricated such that below bandgap light can pass through the device and be absorbed by the inorganic bottom cell. Toward that end, we have developed a transparent top contact for solid-state dye-sensitized solar cells that renders ssDSCs attractive candidates for HTPVs.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2013 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Margulis, George Yan |
|---|---|
| Associated with | Stanford University, Department of Applied Physics. |
| Primary advisor | Fisher, Ian R. (Ian Randal) |
| Primary advisor | McGehee, Michael |
| Thesis advisor | Fisher, Ian R. (Ian Randal) |
| Thesis advisor | McGehee, Michael |
| Thesis advisor | Bent, Stacey |
| Advisor | Bent, Stacey |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | George Yan Margulis. |
|---|---|
| Note | Submitted to the Department of Applied Physics. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2013. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2013 by George Yan Margulis
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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