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Descriptors for Electron and Hole Charge Carriers in Metal Oxides

preprint
submitted on 26.11.2019 and posted on 03.12.2019 by Daniel Davies, Christopher Savory, Jarvist Moore Frost, David Scanlon, Benjamin Morgan, Aron Walsh

Metal oxides can act as insulators, semiconductors or metals depending on their chemical composition and crystal structure. Metal oxide semiconductors, which support equilibrium populations of electron and hole charge carriers, have widespread applications including batteries, solar cells, and display technologies. It is often difficult to predict in advance whether these materials will exhibit localized or delocalized charge carriers upon oxidation or reduction. We combine data from first-principles calculations of the electronic structure and dielectric response of 214 metal oxides to predict the energetic driving force for carrier localization and transport. We assess descriptors based on the carrier effective mass, static polaron binding energy, and Frohlich electron–phonon coupling. Numerical analysis allows us to assign p and n type transport of a metal oxide to three classes: (i) band transport with high mobility; (ii) small polaron transport with low mobility; and (iii) intermediate behaviour. The results of this classification agree with observations regarding carrier dynamics and lifetimes and are used to predict 10 candidate p-type oxides.

History

Email Address of Submitting Author

d.davies16@imperial.ac.uk

Institution

Imperial College London

Country

United Kingdom

ORCID For Submitting Author

0000-0003-4094-5992

Declaration of Conflict of Interest

No conflict of interest.

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