Direct visualization of ultrafast lattice ordering via resonant electron-phonon coupling in 2D hybrid perovskites
| dc.contributor.advisor | Mohite, Aditya D. | en_US |
| dc.creator | Zhang, Hao | en_US |
| dc.date.accessioned | 2021-08-27T18:45:09Z | en_US |
| dc.date.available | 2022-02-01T06:01:12Z | en_US |
| dc.date.created | 2021-08 | en_US |
| dc.date.issued | 2021-08-25 | en_US |
| dc.date.submitted | August 2021 | en_US |
| dc.date.updated | 2021-08-27T18:45:09Z | en_US |
| dc.description.abstract | Understanding and tracing the dynamic interactions between charge carriers and crystal lattice has remained a challenge in photo-excited semiconductors. Specifically, a direct visualization of carrier-lattice interactions (electron-phonon coupling) provides crucial insights in such as hot-carrier lifetime and recombination rates, which are key factors for device fabrications. In this study, we’ve monitored the transient structural response of two-dimensional perovskites (2DPKs) by tracking the evolution of the wavevector-resolved electron diffraction patterns, through femtosecond ultrafast electron diffraction (UED). Analysis of the Bragg peak intensities reveals a unique positive response, suggesting an ultrafast lattice ordering resulting from a resonant transfer from hot-carriers to perovskite lattice. Simulated structural response and calculation of vibrational modes may reveal the presence of non-polar optical phonons, which induces in-plane octahedral tilts and a reduction of distortion toward symmetrized phase, consistent with the predicted electron-phonon interactions through optical deformation potential via non-polar modes. Finally, we show the strength and the dynamics of the reported electron-phonon coupling process can be further tailored via alternating the organic layers of 2D perovskites, resulting in difference in mechanical rigidity and intrinsic distortions. This study on the structural dynamics of 2D perovskites may provide fundamental information on tailoring specific electron-phonon coupling channels, paving a pathway for the design of efficient perovskite-based opto-electronic devices. | en_US |
| dc.embargo.terms | 2022-02-01 | en_US |
| dc.format.mimetype | application/pdf | en_US |
| dc.identifier.citation | Zhang, Hao. "Direct visualization of ultrafast lattice ordering via resonant electron-phonon coupling in 2D hybrid perovskites." (2021) Master’s Thesis, Rice University. <a href="https://hdl.handle.net/1911/111340">https://hdl.handle.net/1911/111340</a>. | en_US |
| dc.identifier.uri | https://hdl.handle.net/1911/111340 | en_US |
| dc.language.iso | eng | en_US |
| dc.rights | Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder. | en_US |
| dc.subject | two-dimensional perovskites | en_US |
| dc.subject | ultrafast diffraction | en_US |
| dc.subject | electron-phonon coupling | en_US |
| dc.title | Direct visualization of ultrafast lattice ordering via resonant electron-phonon coupling in 2D hybrid perovskites | en_US |
| dc.type | Thesis | en_US |
| dc.type.material | Text | en_US |
| thesis.degree.department | Applied Physics | en_US |
| thesis.degree.discipline | Natural Sciences | en_US |
| thesis.degree.grantor | Rice University | en_US |
| thesis.degree.level | Masters | en_US |
| thesis.degree.major | Material Physics | en_US |
| thesis.degree.name | Master of Science | en_US |
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