Photoresponsive IGZO Memcapacitor With Associative Learning Capability

Abstract

Photoresponsive memcapacitors are capable of changing their capacitance in an analog manner in response to light stimuli, with ultralow static power consumption and history-dependent processing. We report an indium gallium zinc oxide (IGZO) memcapacitor based on the mechanism of light-induced effective area variation. The device acts as a photoresponsive artificial synapse, demonstrating its capacitive update under light stimulation akin to the learning and forgetting process in the brain. By synergistically applying light and electrical pulses, the device exhibits Pavlov’s classical conditioning behavior. The learning and adaptation features may arise from the persistent photoconductivity effect in the IGZO active layer. The IGZO memcapacitor allows for processing and storing information directly with selective light, making it useful for creating adaptable optical neuromorphic systems.