2024/10/28 by Zenghua Cai, Chunlan Ma, Cai, Zenghua +1 · 1 citation
Engineering · Materials Science · #Advancements in Solid Oxide Fuel Cells #Computational Physics (physics.comp-ph) #Electronic and Structural Properties of Oxides #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Semiconductor materials and devices
paper · pdf · doi:10.48550/arxiv.2410.20946
openalex publication_date 2024/10/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
SrTiO3 (STO) displays a broad spectrum of physical properties, including superconductivity, ferroelectricity, and photoconductivity, making it a standout semiconductor material. Despite extensive researches, the oxygen partial pressure-dependent conductivity in STO has re-mained elusive. This study leverages first-principles calculations, and systematically investigates the intrinsic defect properties of STO. The results reveal that VO, VSr, and TiSr are the dominant intrinsic defects, influencing STO's conductivity under varying O chemical potentials (oxygen partial pressures). Under O-poor condition, VO is the predominant donor, while VSr is the main acceptor. As the oxygen pressure increases, TiSr emerges as a critical donor defect under O-rich condition, significantly affecting conductivity. Additionally, the study elucidates the abnormal phenomenon where VTi, typically an acceptor, exhibits donor-like behavior due to the formation of O-trimer. This work offers a comprehensive understanding of how intrinsic defects tune the Fermi level, thereby altering STO's conductivity from metallic to n-type, and eventually to p-type across different O chemical potentials. These insights resolve the long-standing issue of oxygen partial pressure-dependent conductivity and explain the observed metallic conductivity in oxygen-deficient STO.