The electronic properties and optical absorption spectrum of the photovoltaic sensitizer [(H3-tctpy)M(NCS)3]- (M = Fe, Ru and Os) in ethanol solvent are investigated using density functional theory/time-dependent density functional theory. The calculated absorption spectrum is in agreement with experiment for ruthenium complex, thus allowing an assignment of UV-visible spectral features of the dye. Red shift in the absorption spectrum is observed moving down the group from iron to osmium. The observed red shift in ruthenium and osmium complexes appears to be related to the destabilization of the occupied orbitals with t2g-NCS π* character. In osmium complex, the increase in the orbital splitting energy d (t2g-eg) is found due to the destabilization of the e g orbitals. The weak d-d transitions are observed only in iron and ruthenium complexes.
|Number of pages||6|
|Journal||Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers|
|Issue number||4 B|
|Publication status||Published - Apr 24 2007|
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)