Defects in Bismuth Vanadate: Insights from First Principles
Licentiate thesis, 2022

Photoelectrochemical water splitting is an attractive technique for sustainable hydrogen production, but its efficiency is heavily dependent on the properties of the semiconducting photoelectrodes used in the process. These properties are intimately connected to the presence of point defects in the materials, and understanding this relationship is a key step towards the development of better photoabsorbers. The effects of single impurities are challenging to probe using experimental techniques, but the use of computer modelling makes it possible to study modifications on the level of individual atoms. This thesis investigates native point defects in bismuth vanadate using hybrid density functional theory. The fundamentals of water splitting and the properties of the material are reviewed. Additionally, the theoretical foundations of the applied computational methods are described. The calculations performed within the thesis highlight the structural complexity of native point defects in bismuth vanadate and the important role that charge localization plays in its defect chemistry. In addition, it is found that oxygen vacancies induce significant lattice distortions at realistic concentrations. Simulated powder X-ray diffraction patterns reveal that this makes phase identification difficult.

defects

oxides

semiconductors

density functional theory

PJ-salen
Opponent: Prof. Itai Panas, Department of Chemistry, Chalmers University of Technology, Sweden

Author

Nicklas Österbacka

Chalmers, Physics, Condensed Matter and Materials Theory

Influence of Oxygen Vacancies on the Structure of BiVO<inf>4</inf>

Journal of Physical Chemistry C,;Vol. 125(2021)p. 1200-1207

Journal article

Charge Localization in Defective BiVO<inf>4</inf>

Journal of Physical Chemistry C,;Vol. 126(2022)p. 2960-2970

Journal article

Roots

Basic sciences

Infrastructure

C3SE (Chalmers Centre for Computational Science and Engineering)

Subject Categories

Materials Chemistry

Condensed Matter Physics

Areas of Advance

Materials Science

Publisher

Chalmers

PJ-salen

Opponent: Prof. Itai Panas, Department of Chemistry, Chalmers University of Technology, Sweden

More information

Latest update

3/23/2022