Marked Enhancement of Photoconductivity and Quenching of Luminescence in Poly(2,5-dialkoxy-p-phenylene vinylene) upon C₆₀ Doping

Abstract

The absorption spectrum and electrical conductivity of poly(2,5-dioctyloxy- p -phenylene vinylene) (OO-PPV) are hardly influenced by doping of a small amount of C 60 , suggesting that C 60 is not an effective dopant for OO-PPV. On the other hand, photoluminescence has been markedly quenched and photoconductivity has been enhanced by several orders of magnitude upon introduction of several mol% of C 60 , suggesting photo-induced charge transfer between OO-PPV and C 60 . These results are discussed in terms of relative electronic energy states of OO-PPV and C 60 . The photoexcited exciton-polaron (Ex-P) is speculated to migrate along 50∼100 monomer units of the polymer main chain in its lifetime and dissociate when encountered with C 60 .