Rapid laser-induced ambient synthesis of highly crystalline Ag@Cu₂O nanowire networks for reconfigurable photoelectrochemical logic and hardware-encrypted communication

Photoelectrochemical (PEC) photodetectors with switchable photocurrent polarity offer a promising route toward secured optical communication. However, achieving high-performance bipolar response typically demands complex hetrostructure fabrication under stringent conditions. Here, we report the rapid, ambient laser-induced assembly of highly crystalline Ag@Cu₂O core-shell nanowire networks driven by a ligand-to-metal charge transfer (LMCT) mechanism. Distinct from conventional thermal growth, this non-equilibrium photochemical strategy promotes kinetically controlled nucleation, establishing intimate semiconductor-metal interfaces with superior charge collection efficiency. PEC devices based on these networks operate in self-powered mode and display broad-spectrum photoresponse. Notably, the photocurrent polarity is reversibly switched not by structural redesign, but by simply tuning the redox potential of the electrolyte through controlled addition of NaHCO₃. This electrolyte-tuned bipolarity enables zero-bias, reconfigurable optical logic gates (AND, NAND, NOT) and a hardware-encrypted communication system based on the Alternate Mark Inversion (AMI) protocol, where the specific electrolyte composition serves as a physical key. Unauthorized interception yields invalid unipolar signals, ensuring physically secured data transmission. This work bridges high-quality materials synthesis, interfacial charge engineering, and functional optoelectronic applications in a single, scalable platform.