Ultrahigh-performance self-powered photodetectors based on hexagonal YbMnO3 ferroelectric thin films by the polarization-induced ripple effect

The use of ferroelectric materials is believed to be a viable way to construct self-powered photodetectors based on the ferroelectric photovoltaic effect. However, the low photocurrent density of ferroelectric materials is a serious drawback that restricts their photo-detection applications. Herein, ultrahigh photo-detection performances are achieved in hexagonal YbMnO3-based self-powered photodetectors by optimizing the macroscopic polarization. The responsivity (R) and detectivity (D*) can reach 0.18/0.15 A W−1 and 6.73 × 1011/5.76 × 1011 Jones under monochromatic light with a wavelength of 365/700 nm when the YbMnO3 thin film [YbMnO3(1040)] is sintered at 1040 °C. These excellent photo-detection performances are attributed to the high short-circuit current density which reaches 10.9 mA cm−2 under 1 sun illumination. A systematic structure and photo-electric characteristic analysis suggests that the formation of a strong domain and the distortion of the crystal structure lead to an enhanced macroscopic polarization in YbMnO3(1040) without changing the bandgap. The enhanced polarization causes a ripple positive effect, which increases the driving force of photo-generated carrier separation and restrains recombination, leading to a high dissociation efficiency. This work demonstrates that the ferroelectric YbMnO3 thin film has great potential in the photo-detection field.