Dual-Bidirectional Optoelectronic Bi2O2Se Single Crystal Enabled by Site-Selective O-Se Substitution for Self-Contained Scene Perception-Recognition-Interaction System

Simultaneous integration of electrical bipolarity and bidirectional photoresponse enables enhanced dynamic scene perception, recognition, and interaction within a single device, represents a formidable yet actively pursued challenge, motivated by applications in intelligent autonomous driving, augmented reality, and related advanced technologies. Here, we report a site-selective O-Se substitution strategy, yielding, for the first time, enables electrically and optically bipolar charge transport in a single-crystalline Bi 2 O 2 Se 2D semiconductor. Their-based filed-effect transistors (FETs) show balanced ambipolar (P/N-type) carrier transport with a record-level of I ON / I OFF ratio over 6000, and broadband positive and negative photoconductivity (PPC/NPC) from 300 to 1400 nm selectively activated under opposite polarity bias conditions. This dual-bidirectional optoelectronic performance is attributable to a wavelength-dependent oxygen adsorption–desorption process that dynamically modulates the electronic band structure and charge transport characteristics. Moreover, we successfully demonstrate its integrated applications in high-dimensional secure optical communication, round-the-clock motion detection and recognition (MDR), and context-aware interaction to dynamic events. The result demonstrates seamless integration of multi-wavelength spectral sensing, in-sensor computing, and hardware-rooted secure communication within such Bi 2 O 2 Se devices, establishing a foundation for next-generation optoelectronic technologies.