Abstract
has appealing properties as an electrode for photoelectrochemical water splitting, yet its practical performance is severely limited by inefficient charge extraction at the interface. Using hybrid DFT calculations, we investigate carrier capture processes by oxygen vacancies () in the experimentally observed ( reconstruction of the dominant (111) surface. Our results show that these are doubly ionized and that associated defects states strongly suppress electron transport. In particular, the excited electronic state of a singly charged plays a crucial role in the nonradiative electron capture process with a capture coefficient of about /s and a lifetime of 0.04 ps, explaining the experimentally observed ultrafast carrier relaxation. These results highlight that engineering the surface chemistry will be a crucial step in optimizing for photoelectrode applications.
- Received 17 March 2021
- Revised 24 August 2021
- Accepted 3 December 2021
DOI:https://doi.org/10.1103/PhysRevResearch.3.043219
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
Published by the American Physical Society