Polarized Ferroelectric Field-Enhanced Self-Powered Perovskite Photodetector

The hybrid organic-inorganic perovskites have been considered as promising candidates for high-performance photodetectors. However, how to fabricate self powered broadband perovskite photodetectors with tunable photoresponse is still challenging. Herein, we design, for the first time, a ferroelectric semiconductor SrTiO3 (STO) and perovskite film hybrid structure based photodetector. After applying appropriate poled bias, the hybrid photodetector exhibits higher responsivity and faster response speed as compared to an unpoled device and a device without an STO ferroelectric interlayer. By optimizing the STO interlayer density, the positively poled photocurrent and response speed are enhanced to 0.956 mA and 0.1 s at zero bias, respectively. The corresponding responsivity is as high as 0.73A/W at a wavelength of 550 nm, which is much higher than that of the device without an STO interlayer. The improved performance is attributed to the fact that positively polarized STO layers can provide a built-in potential and promote the band bending at the semiconductor surface to facilitate the separation and transportation of the photogenerated charge carriers. Our work provides a promising route to design high-performance ferroelectric-perovskite photodetectors.