Effect of doping content of Pr ions on oxygen vacancies in SrTiO3 films

• Fabrication of Sr1−xPrxTiO3 films (x = 0–0.075) by MOD method.
• The oscillating variation of OVs was shown with increasing Pr content.
• The variable valence and doping position of Pr ions are key factor by XPS analysis.

Both undoped and Pr-doped STO films are fabricated on (1 1 1) Pt/Ti/SiO2/Si by metal organic deposition. The influence of Pr dopant on oxygen vacancies is studied using X-ray photoelectron spectroscopy and X-ray diffraction. It is found that the concentration of oxygen vacancies is not decreases with the increase of the content of higher valence Pr ions, but decreases and increases alternatively. These results are associated with the variable valence and doping position of Pr ions, and the possible causes of which are discussed.