Recent advances in a-IGZO synaptic transistors for flexible computing applications

Growing demand for wearable electronics has increased interest in devices that combine mechanical compliance with local information processing. Amorphous indium gallium zinc oxide (a-IGZO) is an attractive material because spatially extended metal-cation s-orbital overlap enables relatively high mobility in amorphous films, and the compatibility with low-temperature deposition supports large-area processing. This review examines recent advances in flexible a-IGZO synaptic transistors. It discusses electron transport and ionic–electronic coupling mechanisms in relation to synaptic plasticity and summarizes relevant electrical and mechanical performance metrics. It then evaluates atomic- and molecular-level engineering of channels, dielectrics, and heterointerfaces, together with gate-stack, one-dimensional, vertical, and multigate architectures. Demonstrations of in-sensor, near-sensor, reservoir, and in-memory computing are assessed across individual devices, arrays, and device-based simulations. Finally, we discuss challenges in film uniformity, reproducible weight storage, mechanically reliable array integration, and hardware–software co-design. Addressing these issues is necessary for moving flexible a-IGZO synaptic devices beyond proof-of-concept demonstrations toward reliable computing systems.