Dynamic Interfacial Charge Regulation for High-Fidelity Broadband Circularly Polarized Light Detection

Circularly polarized light (CPL) carries both chirality and polarization-state information, offering unique opportunities for optical communication, polarization imaging, and three-dimensional displays. However, high-fidelity CPL detection is often limited to relatively narrow spectral ranges, while weak chirality-dependent photocurrent can be readily obscured by dark current and noise during interface-dependent solid-state interfacial charge transport. Here, a broadband photoelectrochemical-type CPL detection platform is developed by coupling a multi-photonic-bandgap chiral polymer modulation layer with a dynamically regulated BiVO₄-RGO-MXene transducer. The stacked chiral polymer films impart wavelength- and chiral-selective optical modulation ranging from 360 to 830 nm, while the adaptive photoelectrochemical interface enables efficient conversion of the encoded optical differences into electrical outputs through dynamic interfacial charge regulation. Consequently, broadband CPL inputs are selectively gated and translated into stable electrical signals within a single compact device. This architecture combines broadband chiral optical modulation with adaptive interfacial charge transduction, alleviating trap-state interference and suppressing noise without increasing structural complexity. The present strategy provides a general route toward compact, broadband, and integration-compatible CPL photodetection. Furthermore, CNN-assisted recognition of CPL-encrypted images demonstrates the capability of the device for noise-robust and machine-readable chiroptical information decoding.