Download DFT characterization of molecular properties of pigments relevant to dye-sensitized solar cells”

Appunti di Fisica ‘10
18 marzo ore 15.30, aula A
Dip. di Fisica della Materia e Ingegneria Elettronica
DFT characterization of molecular properties
of pigments relevant to dye-sensitized solar cells
Dr. Alessandro Sinopoli
Dyes sensitized solar cells (DSSCs) are devices devoted to the conversion of solar
energy into electricity based on a large band gap nanocrystalline semiconductor
sensitized by a dye which is chemically linked to the semiconductor surface and has
substantial absorption in the visible range. Only little is known about dye-sensitizers
molecular properties relevant to the electron injection process. Ground state
geometries, electronic transition energies, and oxidation potentials of several natural
and artificial sensitizers are reported here. The HOMO->LUMO transition describes
all lowest singlet excited states. The computed alignments of the molecular orbitals
of the different molecules, with the band edges of a model TiO2 nanoparticle, provide
additional insights into electronic factors governing the efficiency of dye-sensitized
solar cell devices. Finally we report on several applications of Density Functional
Theory to simulate IR or Raman spectra, electron densities or structural properties.