HOPV12 - Blogs

4 th Hybrid and Organic Photovoltaic Conference -Uppsala 2012 222
C94 - Computational study of porphyrin sensitizers for solar cells: molecular design
and binding mechanisms
Negar Ashari Astani, Basile F. E. Curchod, Ivano Tavernelli, Ursula Roethlisberger
EPFL, EPFL SB ISIC LCBC BCH 4118 (Bâtiment de chimie UN, Lausanne, 1004, CH
An extensive computational study on porphyrin-based dyes including the design of dyes
with optimal optical properties and the study of their chemisorption on the TiO2 substrate has
been performed. These bioinspired porphyrin-based dyes have very similar key characteristics
of the electron transfer processes as the best performing more conventional Ru-based
sensitizers[1]. Furthermore, they exhibit strong Soret and long-wave length Q-band absorption
spectra. In this work, we systematically explored substitutions at the four meso and eight β
positions available for functionalization, to tune the UV-visible absorption spectra of these
promising dyes.
Time dependent density functional theory (TDDFT) calculations were carried out to
determine the vertical absorption spectra. Results of these calculations revealed several new
dyes with better absorption in the red. The additional practical problem of insufficiently strong
anchoring of the dyes on the TiO2 substrate was also addressed.
© SEFIN 2012