Hyper-sensitive piezophotovoltaic effects in ferroelectric nanocylinders

Photocurrent system of the ferroelectric nanocylinder (FNC), including nanodisks, nanorods, and nanowires, sandwiched between metal electrodes with the short-circuit boundary conditions has been designed and investigated. Taking into account the polarization charge screening in the electrodes and near-surface inhomogeneous polarization distribution, a theoretical model for investigating the photoinduced current of the FNC under the illumination of light was established. Our results show that the photocurrent of the FNC can be totally controlled by adjusting its size and states of the polarization up and down. Especially, reversing an applied stress can obviously change the photocurrent of the FNC, which is particularly significant near the stress-dependent para/ferroelectric phase transition. This piezophotovoltaic effect may have good potential for applications in high-sensitivity photomechanical sensors, memories, switchable nanodevices, or other photovoltaic nanodevices. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3428477]