Self-powered visible light photodetector based on Bi_xFeO₃ film

In this study, the self-powered photodetector based on photovoltaic effect was obtained from Bi_xFeO₃ (x = 1, 1.3, 1.5, 1.7) films. In order to study the origin of the photovoltaic effect, the self-polarized structure and defect distribution of the films were characterized by x-ray diffraction, x-ray photoelectron spectroscopy, and piezoelectric force microscopy. In addition, the responsivity (1515 μA/W) and detectivity (1.35Χ10¹¹ Jones) are achieved in the Bi_1.5FeO₃ film at zero bias after receiving 0.2 mW/cm² of irradiation light in the wavelength of 500 nm. The rise and decay time of the photocurrent without bias reaches ∼6 ms and ∼15 ms respectively, and did not weaken after a 11 min cycling test. The self-polarized structure and defect dipoles play an important role in the photovoltaic effect of Bi_xFeO₃ self-powered photodetector. This work lays a foundation for applications in Bi_xFeO₃ self-powered photodetection.