Beyond Cation Disorder: Site Symmetry-Tuned Optoelectronic Properties of the Ternary Nitride Photoabsorber ZrTaN3
Journal
Advanced Energy Materials
ISSN
1614-6832
1614-6840
Date Issued
2024-07-28
Author(s)
Elise Sirotti
Laura I. Wagner
Johanna Eichhorn
Frans Munnik
Verena Streibel
Maximilian J. Schilcher
Benjamin März
Franziska S. Hegner
Matthias Kuhl
Theresa Höldrich
Knut Müller‐Caspary
David A. Egger
Ian D. Sharp
Abstract
Ternary nitrides are rapidly emerging as promising compounds for optoelectronic and energy conversion applications, yet comparatively little of this vast composition space has been explored. Furthermore, the crystal structures of these compounds can exhibit a significant amount of disorder, the consequences of which are not yet well understood. Here, the deposition of bixbyite-type ZrTaN3 thin films is demonstrated by reactive magnetron co-sputtering and observed semiconducting character, with a strong optical absorption onset at 1.8 eV and significant photoactivity, with prospective application as functional photoanodes. It is found that Wyckoff-site occupancy of cations is a critical factor in determining these beneficial optoelectronic properties. First-principles calculations show that cation disorder leads to minor deviations in the total energy but modulates the bandgap by 0.5 eV, changing orbital hybridization of valence and conduction band states. In addition to demonstrating that ZrTaN3 is a promising visible light-absorbing semiconductor and active photoanode material, the findings provide important insights regarding the role of cation ordering on the electronic structure of ternary semiconductors. In particular, it is shown that not only cation order, but also the cationic Wyckoff site occupancy has a substantial impact on key optoelectronic properties, which can guide future design and synthesis of advanced semiconductors.
Subjects
ation disorder
photoabsorber
ternary nitride
wyckoff site occupancy
Publisher
Wiley
Type
journal article