Chiara Ricca^1,2*, Ulrich Aschauer^1,2*

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

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

DOI10.24435/materialscloud:2h-ca [version v1]

Publication date: Feb 07, 2022

How to cite this record

Chiara Ricca, Ulrich Aschauer, Photochemical anisotropy and direction-dependent optical absorption properties in semiconductors, Materials Cloud Archive 2022.23 (2022), doi: 10.24435/materialscloud:2h-ca.

Description

Photochemical reactions on semiconductors are anisotropic, since they occur with different rates on surfaces of different orientation. Understanding the origin of this anisotropy is crucial to engineering more efficient photocatalysts. In this work, we use hybrid density functional theory (DFT) to identify the surfaces associated with the largest number of photo-generated carriers in different semiconductors. For each material we create a spherical heat map of the probability of optical transitions at different wave vectors. These maps allow to identify the directions associated with the majority of the photo-generated carriers and can thus be used to make predictions about the most reactive surfaces for photochemical applications. Results indicate that it is generally possible to correlate the heat maps with the anisotropy of the bands observed in conventional band-structure plots, as previously suggested. However, we also demonstrate that conventional bands-structure plots do not always provide all the informations and that taking into account the contribution of all possible transitions weighted by their transition dipole moments is crucial to obtain a complete picture.

Materials Cloud sections using this data

Files

File name	Size	Description
README.txt MD5md5:daf82f54d86a76307f2e3e43501c4783	1.8 KiB	The README file contains information on the notebooks and data stored in the archive.
paper_optical_anisotropy.tar.gz MD5md5:921c833a31a54c173de74eccb04581b7	4.6 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

DFT hybrid functionals semiconductors anisotropy optical properties photochemistry photocatalysis MARVEL/DD5 SNSF CSCS