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

• Published in: Advanced optical materials 2022-11, Vol.10 (21), p.n/a
• Main Authors: Matsuo, Hiroki, Noguchi, Yuji
• Format: Article
• Language: English
• Subjects: Anisotropy; Broken symmetry; domain engineering; Domain walls; Ferroelectric materials; Ferroelectricity; ferroelectrics; Materials science; Nanomaterials; Optical communication; Optics; photocurrent anisotropy; Photoelectric effect; Photoelectric emission; Photovoltaic cells; photovoltaic effects; Polarization; polarization detection; visible light
• ISSN: 2195-1071; 2195-1071
• DOI: 10.1002/adom.202201280

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. Ferroelectric Mn‐doped BiFeO3 thin films with engineered domain structures exhibit a large photocurrent anisotropy ratio of 7.9 under visible‐light irradiation. Photovoltaic tensor analyses show that the domain‐wall photovoltaic effect activated by Mn doping provides the large anisotropy. Photocurrent simulations indicate that the anisotropy can be further increased by increasing the domain‐wall density. Ferroelectrics are possible candidates for visible‐light polarization detection.