Donor defects and small polarons on the TiO2(110) surface

Autor(en)

P.G. Moses, Anderson Janotti, Cesare Franchini, Georg Kresse, Chris G. Van de Walle

Abstrakt

The role of defects in the chemical activity of the rutile TiO2(110) surface remains a rich topic of research, despite the rutile (110) being one of the most studied surfaces of transition-metal oxides. Here, we present results from hybrid functional calculations that reconcile apparently disparate views on the impact of donor defects, such as oxygen vacancies and hydrogen impurities, on the electronic structure of the (110) rutile surface. We find that the bridging oxygen vacancy and adsorbed or substitutional hydrogen are actually shallow donors, which do not induce gap states. The excess electrons from these donor centers tend to localize in the form of small polarons, which are the factual cause of the deep states ∼1 eV below the conduction band, often observed in photoelectron spectroscopy measurements. Our results offer a new framework for understanding the surface electronic structure of TiO2 and related oxides.

Organisation(en)

Computergestützte Materialphysik

Externe Organisation(en)

University of California, Santa Barbara

Journal

Journal of Applied Physics

Band

119

Anzahl der Seiten

5

ISSN

0021-8979

DOI

https://doi.org/10.1063/1.4948239

Publikationsdatum

2016

Peer-reviewed

Ja

ÖFOS 2012

103025 Quantenmechanik, 103036 Theoretische Physik, 103015 Kondensierte Materie, 103009 Festkörperphysik

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/2ed71ebc-b9cc-4eba-8061-161f8696c2b0