Density functional theory investigation of Pr adsorption on the anatase TiO2(101) surface for photovoltaic applications

We present first-principles density functional theory calculations for the structural, electronic, and optical properties for the Pr-doped anatase TiO2(101) surface. The DFT+U formalism is used to describe the strong correlations arising from the localized Ti 3d and Pr 4f orbitals. The incorporation of Pr into the surface results in the impurity states fall into the band gap, improving the optical activity of the TiO2(101) surface both in the UV–visible and the near-IR range. In addition, we probe the adsorbate–dopant interaction using benzoic acid, a prototypical dye molecule as an example. Molecular adsorption energies as well as the optical properties are improved as a result of the inclusion of Pr.