Organic Molecule - Fullerene Mixture for a High Efficiency Photovoltaic Device: Theoretical Study
H, Mizuseki, K. Niimura, C. Majumder and Y. Kawazoe
Institute for Materials Research, Tohoku University, JP
Keywords: phthalocyanine-fullerene supramolecule, molecular device, guest-host system, organic solar cell, photocurrent generation, simulation
The current general trend in research and development of photovoltaic elements is aimed at producing lower cost devices. An encouraging breakthrough in the development of highly efficient materials has been achieved by mixing electron-donor type polymers with suitable electron acceptors. Many fullerene-based supramolecules have been proposed as potential organic photovoltaic devices, because these materials have a large and flexible absorption combined with electrical properties similar to an inorganic semiconductor. We investigated the geometric and electronic structure of pi-conjugated molecule - fullerene complex using an ab initio quantum mechanical calculations. The electron transport of the molecules was analyzed based on spatial distribution of their frontier orbitals (HOMO and LUMO). It was found that the HOMO’s were localized on the donor sub-unit and the LUMO’s were localized on the acceptor sub-unit. The localization of the LUMO state on the donor moiety depended on excess electrons and the acceptor group.
NSTI Nanotech 2003 Conference Technical Program Abstract