  The mechanism of negative capacitance, e.g. inductance, induced by a
sufficient electrical field in the organic device is investigated. The cations
in organic bulk are proposed to be driven by the applied voltage and to
accumulate at the interface, and further to generate the surface states or
media states. These states result in a larger junction current through the
device, indicating the negative capacitances which are simulated in three
situations: impedance spectrum, capacitance measurement and current response.
This simple kinetic model may be helpful to understand why the negative
capacitance phenomenon is observed in various organic devices.
