Fluorine-doping in titanium dioxide by ion implantation technique

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Vol. 206; pp. 254 - 258
• Main Authors: Yamaki, T., Umebayashi, T., Sumita, T., Yamamoto, S., Maekawa, M., Kawasuso, A., Itoh, H.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-05-2003
• Subjects: Anion doping; Electronic structure; Ion implantation; Positron annihilation; RBS/channeling; Titanium dioxide (TiO 2); Ion implantation; Electronic structure; 61.72.−y; 85.40.Ry; Titanium dioxide (TiO 2); 71.55.−i; RBS/channeling; 61.80.Jh; Anion doping; Positron annihilation
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/S0168-583X(03)00735-3

We implanted 200 keV F
+ in single crystalline titanium dioxide (TiO
2) rutile at a nominal fluence of 1
×
10
16 to 1
×
10
17 ions
cm
−2 and then thermally annealed the implanted sample in air. The radiation damage and its recovery process during the annealing were analyzed by Rutherford backscattering spectrometry in channeling geometry and variable-energy positron annihilation spectroscopy. The lattice disorder was completely recovered at 1200 °C by the migration of point defects to the surface. According to secondary ion mass spectrometry analysis, the F depth profile was shifted to a shallower region along with the damage recovery and this resulted in the formation of an F-doped layer where the impurity concentration steadily increased toward the surface. The F doping proved to provide a modification to the conduction-band edge of TiO
2, as assessed by theoretical band calculations.