Ultralow-energy consumption SnSe/ZnO heterojunction artificial optoelectronic synaptic devices towards ultraviolet optical communication applications

Abstract

Oxide-based optoelectronic synapse (OES) devices have attracted much attention for their significant potential applications in developing next-generation artificial intelligence bionic vision systems. However, low-power devices for ultraviolet (UV) optical communication applications still face great challenges due to large operation voltages, high noise currents, and weak photoresponse. Herein, ultralow-energy consumption OES devices based on SnSe/ZnO heterojunctions are fabricated. The SnSe/ZnO heterojunctions exhibit non-volatile resistance switching behavior under photoelectric stimulation, demonstrating advanced synaptic functionalities. Owing to its unique interfacial effects and light-harvesting capabilities, the device achieves a robust response to weak light signals (26.9 μW cm⁻²) with an energy consumption of 81.0 fJ, which is 2–3 orders of magnitude lower than that of other similar devices and close to the level of biological synapses. A 4 × 4 OES array was fabricated, realizing bionic visual image recognition and learning behaviors. Especially, the fabricated OES devices were demonstrated to convert optical Morse code signals into distinct synaptic currents, thereby exhibiting UV optical communication functionality. This work not only demonstrates the feasibility of regulating complex synaptic behaviors in heterojunction devices but also provides an effective strategy to develop advanced artificial intelligence bionic visual systems towards UV optical communication.