Ferroelectric Polarization‐Assisted Sensitive and High‐Power Photodetector in Broad Ultraviolet‐to‐Visible Range

Light‐sensitive electronic devices based on semiconductor P–N junctions have been widely used as photodetectors and solar cells. In order to improve the overall performance of such photosensitive devices, new yet simple design is required. In this work, a simple sandwich structure is proposed by combining a new ferroelectric oxide Bi₆FeCoTi₃O₁₈ with graphene. A highly sensitive photodetector is then realized benefiting from the ferroelectric polarization assisted charge separation, as well as from the unique features of graphene such as the extreme sensibility, ballistic transportation, and broadband absorption. The new device has a remarkable on–off response as high as 2 × 10³% under a Xe light‐source irradiation. The ferroelectric polarization enhances the photoresponse by about 2 × 10⁴% when compared with a reference sample. Additionally, the new device is sensitive to a wide‐spectrum from visible to ultraviolet, and is tolerant to high power of the incident light. This unique design opens up a new way to develop next‐generation photoelectric devices that can be both proficient and cost effective.