866206-35-1Relevant articles and documents
Efficient light harvesting by using green Zn-porphyrin-sensitized nanocrystalline TiO2 films
Wang, Qing,Campbell, Wayne M.,Bonfantani, Edia E.,Jolley, Kenneth W.,Officer, David L.,Walsh, Penny J.,Gordon, Keith,Humphry-Baker, Robin,Nazeeruddin, Mohammad K.,Graetzel, Michael
, p. 15397 - 15409 (2008/10/09)
A series of novel intense green porphyrins containing carboxylate anchoring groups have been shown to have potential as light sensitizers in TiO2 solar cells. The electrochemical, photophysical, and photoelectrochemical properties of a series of novel green Zn porphyrins as well as density functional theory (DFT) and time-dependent DFT (TDDFT) calculations on zinc tetraphenylporphyrin (ZnTPP), cyano-3-(2′-(5′,10′,15′,20′ttet raphenylporphyrinato zinc(II)yl)-acrylic acid (ZN-3), and 3-(trans-2′-(5′,10′15′,20′-tetr aphenylporphyrinato zinc(II)yl)-acrylic acid (Zn-5). DFT and TDDFT calculations showed that the presence of electron-withdrawing moieties on the substituent modulates the electronic absorption spectrum through stabilization of the energies of the LUMO and LUMO + 2. The extension of the LUMO and LUMO + 2 onto the substituent implied that occupation of these molecular orbitals offers the possibility of electron transfer from the substituent to the TiO2 surface. The ground- and excited-state redox potentials showed that the porphyrins possess suitable potentials to inject electrons into the TiO2 substrate, yielding 85% incident-to-electron conversion efficiencies (IPCE). Among the reported porphyrins, the green Zn-3 showed the highest power conversion efficiency obtained so far in nanocrystalline films.
