Engineering contact layers in metal halide perovskite solar cells using atomic layer deposition
Abstract/Contents
- Abstract
- Solar energy is an attractive, renewable energy source because of its massive abundance and its capacity for distributed generation. Photovoltaics (PV) allow us to convert this solar energy directly into usable electricity. Metal halide perovskite solar cells are a new, thin film PV technology on the cusp of commercialization; however, more research is needed to improve their power conversion efficiency and long-term stability, as well as to scale-up their manufacturing. Contact layers and their interfaces with the perovskite absorber are an important component in each of these facets of research. Engineering these contact layers to improve the collection of photogenerated charge carriers often requires precise control over their film properties, such as thickness, composition, and crystallinity. Atomic layer deposition is a versatile, nanoscale synthesis tool that is well-suited for these applications. In this dissertation, we develop low temperature (< 100 C) ALD processes to grow metal oxide contact layers above the perovskite absorber. We focus primarily on vanadium oxide and tin oxide, which are hole- and electron-selective contact materials, respectively. Conformal ALD vanadium oxide contacts enable the fabrication of semi-transparent devices which have potential applications as the wide band gap subcell in tandem solar cells. Tuning the organic hole contact in these devices also leads to improvements in device photocurrent. We show that the ALD vanadium oxide is morphologically stable at temperatures (70 C) relevant to solar cell operation in the field, resulting in devices with good long-term stability. The growth behavior of ALD contacts also has important implications for overall solar cell performance and stability. We find that functionalizing the ALD growth surface to help initiate film growth leads to more compact ALD tin oxide contacts that extend the lifespan of perovskite solar cells. Lastly, we investigate strategies to limit adverse reactions between ALD metal-organic precursor molecules and the perovskite that lead to a poor interface for charge extraction from the solar cell.
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 | 2021; ©2021 |
| Publication date | 2021; 2021 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Raiford, James Andrew |
|---|---|
| Degree supervisor | Bent, Stacey |
| Thesis advisor | Bent, Stacey |
| Thesis advisor | Bao, Zhenan |
| Thesis advisor | Tarpeh, William |
| Degree committee member | Bao, Zhenan |
| Degree committee member | Tarpeh, William |
| Associated with | Stanford University, Department of Chemical Engineering |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | James Andrew Raiford. |
|---|---|
| Note | Submitted to the Department of Chemical Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2021. |
| Location | https://purl.stanford.edu/ss510dw2825 |
Access conditions
- Copyright
- © 2021 by James Andrew Raiford
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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