2002/05/31 by J. R. Simpson, H. D. Drew, S. R. Shinde +4
Chemistry · Materials Science · Physics and Astronomy · #Absorption (acoustics) #Absorption edge #Analytical Chemistry (journal) #Anatase #Band gap #Chemistry #Condensed matter physics #Copper-based nanomaterials and applications #Coulomb #Doping #Electronic and Structural Properties of Oxides #Impurity #Materials science #Optical conductivity #Optics #Photocatalysis #Physics #ZnO doping and properties #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.69.193205
5 pages, 4 figures, 1 table; Version 2 - major content revision
arxiv created 2003/08/27 · openalex publication_date 2004/05/28 · arxiv updated 2013/05/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report on the optical properties of magnetic cobalt-doped anatase phase titanium dioxide Ti_1\ensuremath-xCoxO_2\ensuremath-\ensuremathδ films for low doping concentrations, 0<~x<~0.02, in the spectral range 0.2<~\ensuremath\Elzxh\ensuremathω<5eV. For well oxygenated films (\ensuremathδ\ensuremath≪1) the optical conductivity is characterized by an absence of optical absorption below an onset of interband transitions at 3.6 eV and a blueshift of the optical band edge with increasing Co concentration. The absence of below band gap absorption is inconsistent with theoretical models which contain midgap magnetic impurity bands and suggests that strong on-site Coulomb interactions shift the O band to Co-level optical transitions to energies above the gap.