Precisely Tailoring Ferroelectric Photocurrent via Magnetic Spin Chain toward Efficient Self-Powered UV Photodetectors

The study of Aurivillius multiferroic films has become increasingly prevalent in the contents of solar energy and light-sensitive detectors. In principle, the characters of photocarrier separation driven by ferroelectric polarization can be candidates for self-powered photodetectors. In this work, magnetic Fe doping is proposed for constructing Fe–O–Fe spin chain structures, which not only serve as a scaffold for electron transport but also combine ferroelectric polarization and magnetic exchange in Bi4Ti3–x Fe x O12 (x = 0, 0.5, 0.7, 0.8, 0.9, and 1.0) multiferroic UV photodetector. Using this approach, the precise control of the photocurrent and the performance improvement of the photoelectric readout are then realized, with a noise equivalent power of 9.8 × 10–14 W and detectivity D* ∼ 7.2 × 1012 Jones. Furthermore, the outstanding energy conversion of ∼3.7% under AM 1.5 G irradiation is significant for future practical self-powered detection.