2010/03/31 by Letizia Chiodo, J. M. Garcı́a-Lastra, Juan Maria Garcia-Lastra +6 · 5 citations
Chemistry · Materials Science · Physics and Astronomy · #Ab initio #Anatase #Band gap #Chemistry #Condensed matter physics #Copper-based nanomaterials and applications #Density functional theory #Electronic and Structural Properties of Oxides #Electronic structure #Energy (signal processing) #Exciton #Materials science #Optical spectra #Perturbation theory (quantum mechanics) #Physics #Quantum Dots Synthesis And Properties #Quantum mechanics #Spectral line #Statistical physics #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.82.045207
33 pages, 7 figures
arxiv created 2010/03/31 · openalex publication_date 2010/07/22 · arxiv updated 2015/05/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We present a unified ab initio study of electronic and optical properties of TiO2 rutile and anatase phases with a combination of density-functional theory and many-body perturbation-theory techniques. The consistent treatment of exchange and correlation, with the inclusion of many-body one-particle and two-particles effects in self-energy and electron-hole interaction, produces a high-quality description of electronic and optical properties, giving, for some quantities, the first available estimation for this compound. In particular, we give a quantitative estimate of the electronic and direct optical gaps, clarifying their role with respect to previous measurements obtained by various experimental techniques. We obtain a description for both electronic gap and optical spectra that is consistent with experiments by analyzing the role of different contributions to the experimental optical gap and relating them to the level of theory used in our calculations. We also show the spatial properties of excitons in the two crystalline phases, highlighting the localization character of different optical transitions. This paper aims at understanding and firmly establishing electro-optical bulk properties, yet to be clarified, of this material of fundamental and technological interest for green energy applications.