Multicolor Fully\nLight-Modulated Artificial Synapse\nBased on P‑MoSe<sub>2</sub>/P<sub><i>x</i></sub>O<sub><i>y</i></sub> Heterostructured Memristor

Developing brain-inspired neuromorphic paradigms is imperative\nto breaking through the von Neumann bottleneck. The emulation of synaptic\nfunctionality has motivated the exploration of optoelectronic memristive\ndevices as high-performance artificial synapses, yet the realization\nof such a modulatory terminal capable of full light-modulation, especially\nnear-infrared stimuli, remains a challenge. Here, a fully light-modulated\nsynaptic memristor is reported on a P-MoSe<sub>2</sub>/P<sub><i>x</i></sub>O<sub><i>y</i></sub> heterostructure formed\nby a facile one-step selenization process. The results demonstrate\nsuccessful achievement of multiwavelength (visible 470 nm to near-infrared\n808 nm) modulated switching operations (reset in 0.21–0.97\nV) and diverse synaptic behaviors, including postsynaptic current,\npaired-pulse facilitation, short- and long-term memory (STM and LTM),\nand learning–forgetting. Notably, the device can exhibit a\n3.42 μA PSC increase under six identical 655 nm stimuli, a 11.90–46.24\nμA PSC modulation by changing 808 nm light intensity from 6\nto 14 mW/cm<sup>2</sup>, and a transition from STM to LTM lasting\nbetween 2.47 and 4.27 s by a prolonged 808 nm pulse from 1 to 30 s.\nA novel\npossible light-induced switching mechanism in such a heterostructure\nis proposed. Furthermore, brain-like light-stimulated memory behavior\nand Pavlov’s classical conditioning demonstrate the device’s\ncapacity for processing complex inputs. The study presents a design\ntoward a multiwavelength modulated artificial visual system for color\nrecognition.