B3LYP and self consistent charge density functional tight binding studies of the organic dye sensitized nanocrystalline solar cell

Phenyl-conjugated oligoene sensitizers for TiO₂ solar cells was studied. Four different organic-dye photosensitizers, Y1, O1, O2, and O5, that contain a N,N-diphenylaniline moieties as the donor part and a conjugated (-CH=CH-) unit connecting with the cyano (-CN) and carboxyl (-COOH) groups as the acceptor part were studied. The binding nature of the dyes on TiO₂2 anatase model was calculated with SCC-DFTB and B3LYP method. The -COO- group preferred to bind to the TiO₂ anatase surface via bridging binding mode. The rate of electron transfer process between the dye and the TiO₂ surface was linked to the length of the conjugated (-CH=CH-) unit, and on the number of -COO- group binding to the solar cell surface. This is an abstract of a paper presented at the 231st ACS National Meeting (Atlanta, GA 3/26-30/2006).