Effects Of Oxygen And Illumination On The Photovoltaic Properties Of Organic Solar Cells Based On Phtalocyanine : Fullerene Bulk Heterojunction

The authors report factors that limit the photovoltaic parameters of organic solar cells based on phtalocyanine:fullerene bulk heterojunction. They show that the device photovoltaic properties and their stability are strongly influenced by O-2 impurities. Oxygen affects mostly the photoelectrical properties of the fullerene and the state of the interface between phtalocyanine and fullerene domains. The illumination of the devices, especially in the wavelength range < 570 nm, induces photodiffusion of the oxygen into fullerene material and promotes formation of O-2-fullerene dipoles and additional recombination levels due to C-O reactions that accelerate the device degradation. (c) 2007 American Institute of Physics.