High-performance self-powered amorphous-BaTiO3/p-Si heterojunction photodetector controlled by ferroelectric effect

Abstract

The coupling of ferroelectric and photoelectric effects provides a promising alternative for enhancing the performance of the photodetectors. Here, a high-performance self-powered UV–visible photodetector enhanced by the ferroelectric effect has been demonstrated on amorphous BaTiO3/p-Si heterojunction. When the depolarization field in the ferroelectric BaTiO3 layer is in the same direction as the built-in field at the heterojunction, the responsivities of the device at 0 V can be significantly improved to 14 mA/W, 27 mA/W, and 223 mA/W at 254 nm, 365 nm, and 600 nm, respectively, which is superior to any other reported BaTiO3-based self-driven photodetectors. In addition, the device possesses a quick response speed with rising/fall times of 450 µs/460 µs at 254 nm and 80 µs/140 µs at 600 nm. Moreover, due to the defect-assistant recombination of photogenerated carriers at the amorphous BaTiO3/p-Si interface and grain boundaries in amorphous BaTiO3, the spike of transient photocurrent can be visualized under 254 nm illumination. This work presents a novel strategy for the design and research of high-performance self-powered photodetectors.