Analysis of the Operating Mechanism of Optoelectronic Synaptic Devices: From Materials to Device

Optoelectronic synaptic devices have garnered significant attention for their potential in neuromorphic computing, offering a pathway to overcome the limitations of von Neumann architectures by enabling parallel processing, low power consumption, and integrated sensing-memory-processing functionalities. These devices emulate biological synapses through mechanisms such as light-induced charge trapping/detrapping and light-driven ion migration, which support synaptic plasticity and non-volatile memory. However, performance limitations persist due to dependencies on device architecture and material properties. This article provides a comprehensive analysis of how different structural configurations—including two-terminal and three-terminal designs—along with various material systems, such as silicon-based semiconductors, two-dimensional materials, perovskites, organic polymers, and MXene-based composites, critically influence operational characteristics like responsivity, switching speed, energy efficiency, and environmental stability. By reviewing recent advances in heterojunction engineering and ion-gated transistors, this study underscores the importance of optimizing both material selection and device geometry to achieve high-performance, biomimetic optoelectronic synapses suitable for next-generation visual and cognitive computing applications.