The calculated band edge positions of 3d and 4d transition metal-doped TiO2. The black line is taken as the condition that neglects the impurity levels, and the red line represents the condition that considers the impurity levels. The black line with double arrow is the band gap energy of pure TiO2 corrected by scissors operator. The blue dashed lines represent the CB/VB edge potential of pure TiO2.
Wang et al. Nanoscale Research Letters 2014 9:46 doi:10.1186/1556-276X-9-46