Leakage current and polarization domains in ferroelectric nanogenerators for energy harvesting

Energy harvesting based on the transformation of mechanical into electrical energy is under investigation. Mechanical deformations from ambient parasitic vibrations serve as energy source for our nanogenerator concept with barium titanate as ferroelectric material. The energy harvesting process is enabled by the designed polarization domain topology. Due to the deformation in the ferroelectric film, the polarization domains reorder resulting alternating charge density within electrodes. Defects and other impurities in the single crystal turn the ferroelectric film into a semiconductor. We account for leakage current mechanisms in our finite element phase field model phenomenologically. Ohm's law (OL) and space‐charge‐limited‐ current (SCLC) are presented by linear or quadratic functions for the current density, respectively. The distance between the electrodes as well as the ferroelectric film thickness have an immense influence on the leakage current density. Further investigations focus on the influence of polarization domain topology on the leakage current.