Photovoltaic–Pyroelectric Coupled Effect Based Nanogenerators for Self‐Powered Photodetector System

Abstract Ferroelectric material BiFeO 3 with narrow bandgap of 2.67 eV can be more suitable to fabricate photodetectors instead of solar energy harvesters because of low energy conversion efficiency. Herein, a BiFeO 3 film‐based self‐powered photodetector is reported by using the photovoltaic–pyroelectric coupled effect to enable a fast sensing of 450 nm light illumination. Compared with photovoltaic effect, the photosensitivity parameters including photoconductive gain, responsivity, and specific detectivity can be enhanced by more than 9.7 times at light intensity of 0.86 mW cm −2 by utilizing light‐induced photovoltaic–pyroelectric coupled effect. Moreover, a self‐powered photodetector array system is achieved to detect 450 nm light by analyzing the real‐time recorded output voltage signals as a mapping figure. In this work a new route to realize the performance enhancement of photodetector via photovoltaic–pyroelectric coupled effect on ferroelectric materials, which has great significance in extending the field of self‐powered photodetectors is described.