Small polarons and point defects in barium cerate
Date
2015-12-28
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Publisher
American Physical Society
Abstract
Barium cerate (BaCeO3) is a well-known ionic conductor of both hydrogen and oxygen. In applications, it
is frequently doped (for instance with Y) to increase stability and promote diffusion. However, the effects of
doping and native defects are not fully understood. Computational studies have been stymied by the nature
of the conduction band, which is made up of cerium 4f states. These states present a challenge to ab initio
techniques based on density functional theory within the standard approximations for exchange and correlation.
Using a hybrid functional, we investigate the effects of hydrogen impurities and native defects on the electrical
and optical properties of BaCeO3. We discuss the tendency of excess electrons or holes to localize in the form
of small polarons. We also explore the interactions of polarons with hydrogen impurities and oxygen vacancies,
and their impact on luminescence properties.
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Citation
Swift, Michael, Anderson Janotti, and Chris G. Van de Walle. "Small polarons and point defects in barium cerate." Physical Review B 92.21 (2015): 214114.