Electrically Switchable Bipolar Polarization-Sensitive Photodetection Based on a Biaxial Ferroelectric Semiconductor

Controlling the optoelectronic properties of semiconductors by an electric field is crucial for modern electronics, information processing, computing devices, and optical communication. The electrically switchable polarization feature of ferroelectrics offers the potential for manipulating light–matter interactions. Herein, we demonstrate the electrically switchable bipolar polarization-sensitive photodetection in a biaxial ferroelectric semiconductor (4,4-DFPD)₂PbI₄ (4,4-DFPD is 4,4-difluoropiperidinium). By altering the polarization direction via an electric field, we induce corresponding changes in the anisotropic photoresponse, which is driven by the bulk photovoltaic effect. Based on this phenomenon, we put forward an encrypted optical communication model defined by biaxial ferroelectrics and successfully implement the encryption/decryption transmission process of SOS signals. This work provides new insights into the electrical control of light–matter interactions and multiaxial ferroelectric optoelectronic applications.