In a recent study published in Angewandte Chemie ("Electrically Switchable Circularly Polarized Light Detection in Optically Active Ferroelectric"), a team led by Prof. LUO Junhua and Prof. LI Lina from the Fujian Institute of Research on the Structure of Matter of the Chinese Academy of Sciences developed an optically active hybrid perovskite ferroelectric, BnA2MA2Pb3Br10 that enables self-powered and electrically switchable circularly polarized light (CPL) detection.
CPL detection is important for advancing photonic and quantum technologies, including applications in quantum communication, chiral sensing, and high-density optical information storage. Conventional CPL detection relies on semiconductors combined with bulky optical components, while chiral semiconductors can directly sense CPL through intrinsic chiroptical anisotropy.
However, electrically reconfigurable CPL detection remains largely unexplored, limiting its application in intelligent systems that demand flexible encoding, secure transmission, and multi-state multiplexing.
In this study, the research team designed BnA2MA2Pb3Br10 by combining ordered organic cations with a distorted inorganic framework to break inversion symmetry. Single-crystal structural analysis revealed that the material belongs to the optically active mm2 point group, with spontaneous polarization along the c-axis. Ferroelectric measurements further confirmed its switchable polarization.
Benefiting from its ferroelectricity and bulk photovoltaic effect, BnA2MA2Pb3Br10 exhibited a photovoltaic response under 405 nm illumination, with an open-circuit voltage of approximately 0.25 V. The device achieved a responsivity of 18.3 mA W-1 and a detectivity of 3.2×1011 Jones at 2.2 μW cm-2. Upon ferroelectric polarization reversal, both the photovoltage and photocurrent direction reversed, showing that the photovoltaic response can be electrically controlled through polarization switching.
Further measurements revealed a clear difference in photocurrent between left- and right-handed CPL at 0 V, yielding an anisotropy factor of up to 0.62. After positive and negative poling, the relative photocurrent responses to left- and right-handed CPL were reversed. This demonstrates that ferroelectric switching enables electrical inversion of CPL selectivity.
According to the researchers, this study demonstrates that ferroelectric polarization reversal allows the CPL detection preference to be reversibly switched, providing dynamic electrical control over the chiroptical response.
The findings provide a strategy for developing self-powered and electrically reconfigurable polarization-sensitive optoelectronic devices, they said.
Read the original article on Chinese Academy of Sciences.
