High Photocurrent Anisotropy in Domain‐Engineered Ferroelectrics for Visible‐Light Polarization Detection

Abstract Visible‐light polarization detection is a critical challenge for next‐generation light communication and imaging technologies. While low‐dimensional nanomaterials exhibit polarization‐dependent photocurrents originating from their anisotropic absorption, ferroelectric photovoltaics provide a photocurrent derived from spatial inversion symmetry breaking. Here, it is reported that domain‐engineered ferroelectrics are promising materials for visible‐light polarization detection. Polarization angle‐resolved photocurrent measurements demonstrate that the introduction of domain walls in ferroelectric BiFe_0.95Mn_0.05O₃ films increases the photocurrent anisotropy ratio up to 7.9 under visible light with hν = 2.4 eV (λ = 515 nm), which is much higher than that of typical nanomaterials (≈2–3). Simulations of polarization‐dependent photocurrents show that the domain walls provide an additional degree of freedom for designing ferroelectrics with quite high photocurrent anisotropy. This study opens up the possibility of developing ferrophotovoltaic‐based visible‐light polarization detectors with simple device structures.