Surface potential measurement of fullerene/copper phthalocyanine films on indium tin oxide electrode by Kelvin probe force microscopy

摘要

Various organic semiconductor thin films were deposited on an indium tin oxide (ITO) electrode/glass substrate to simulate organic solar cells. The electrical properties at the organic/inorganic and organic/organic interfaces were evaluated by dynamic-mode atomic force microscopy (DFM) together with Kelvin probe force microscopy (KFM). By employing the frequency modulation (FM) method, the DFM/KFM system allows for not only consistent imaging over a wide scanning area, but also highly sensitive detection of the surface potential. The charge carrier behavior at the interface was clarified by simultaneously obtaining topographic and surface potential images of the same area using DFM/KFM and depicting the energy band diagram with band bending in the fullerene (C_(60)) film.