Optical properties of nanostructured TiO2

V.C. FUERTES; C.F.A. NEGRE; F. Y. OLIVA; C.G. SÁNCHEZ

Conferencia; Pan-American Advanced Studies Institutes (PASI) on Electronic Properties of Complex Systems”; 2011

The properties of nanomaterials differ from bulk due to their large surface/volume ratio. In the case of semiconductors, reduction in size causes a drastic change in their electronic structure [1]. Nanostructured semiconductors have encountered applications in electrochemistry, catalysis, dye sensitized solar cells, etc. precisely because of these novel properties. Many other applications are based on their singular optical properties arising from quantum confinement. In this work we simulate the absorption spectra of a series of TiO2 nanospheres of different radii and crystalline structure. These simulations were performed within a full quantum dynamics framework, by considering the electronic response of the system to an initial electromagnetic pulse. The electronic structure representation was carried out with a DFT based Tigth-Binding Hamiltonian. This method has been already successfully applied to calculate the absorption spectra of metallic NPs and photosynthetic pigments [2, 3]. [1] F. Chen, J. Hihath, Z. Huang, X. Li, y N. J. Tao. Annu. Rev. Phys. Chem., 20 58, 535–564. [2] C. F. A. Negre y C. G. Sánchez. J. Chem. Phys., 2008, 129, 034710. [3] M. B. Oviedo, C. F. A. Negre, y C. G. Sánchez. Phys. Chem. Chem. Phys., 20 12, 6706–11.