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

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 BiFe0.95Mn0.05O3 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.