Chiara Ricca^1,2*, Ulrich Aschauer^1,2*, Lisa Grad³, Matthias Hengsberger³, Jürg Osterwalder³

1 Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland

2 National Centre for Computational Design and Discovery of Novel Materials (MARVEL), Switzerland

3 Department of Physics, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland

* Corresponding authors emails: chiara.ricca@dcb.unibe.ch, ulrich.aschauer@dcb.unibe.ch

DOI10.24435/materialscloud:rr-2n [version v1]

Publication date: Mar 05, 2021

How to cite this record

Chiara Ricca, Ulrich Aschauer, Lisa Grad, Matthias Hengsberger, Jürg Osterwalder, Importance of surface oxygen vacancies for ultrafast hot carrier relaxation and transport in Cu2O, Materials Cloud Archive 2021.39 (2021), doi: 10.24435/materialscloud:rr-2n.

Description

Cu2O has appealing properties as an electrode for photo-electrochemical 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 (VO) in the experimentally observed (√3×√3)R30° reconstruction of the dominant (111) surface. Our results show that these VO are doubly ionized and that associated defects states strongly suppress electron transport. In particular, the excited electronic state of a singly charged VO plays a crucial role in the non-radiative electron capture process with a capture coefficient of about 10^-9 cm3/s and a lifetime of 0.04 ps, explaining the experimentally observed ultrafast carrier relaxation. These results highlight that engineering the surface VO chemistry will be a crucial step in optimizing Cu2O for photoelectrode applications.

Materials Cloud sections using this data

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File name	Size	Description
README.txt MD5md5:9679fc355c860b050a2558bb7bb5e942	3.3 KiB	The README file contains information on the notebooks and data stored in the archive.
paper_Cu2O.tar.gz MD5md5:0a40299a6a831c3e9296708f10f27781	2.6 GiB	The compressed file contains the python and bash scripts, and the folders with the data used in the Jupiter notebooks to produce the plots and tables found in the publication.

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External references

Keywords

hybrid DFT Cu2O carrier capture surface reconstruction oxygen vacancies 2PPE SNSF CSCS