The equivalent circuit model of the heterojunction organic photovoltaic (OPV) cells consisting of 20-nm-thick zinc-octaethylporphyrin [Zn(OEP)] and 30 nm-thick C60 films respectively used as donor and acceptor layers has been determined using impedance spectroscopy under dark and illumination (100mW/cm2, AM1.5) conditions. Under dark condition, the equivalent circuit consisting of a series resistance and two-RC (R: resistance, C: capacitance) circuits corresponding to individual layers well reproduced the impedance spectra. On the other hand, the four-RC circuit model, in which the additional two RC circuits corresponded to individual films in the vicinity of the Zn(OEP)/C60 interface, could explain the impedance spectra obtained under illumination condition.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)