A light-stimulated synaptic transistor with synaptic plasticity and memory functions based on InGaZnO_x–Al₂O₃ thin film structure

In this work, a synaptic transistor based on the indium gallium zinc oxide (IGZO)–aluminum oxide (Al₂O₃) thin film structure, which uses ultraviolet (UV) light pulses as the pre-synaptic stimulus, has been demonstrated. The synaptic transistor exhibits the behavior of synaptic plasticity like the paired-pulse facilitation. In addition, it also shows the brain's memory behaviors including the transition from short-term memory to long-term memory and the Ebbinghaus forgetting curve. The synapse-like behavior and memory behaviors of the transistor are due to the trapping and detrapping processes of the holes, which are generated by the UV pulses, at the IGZO/Al₂O₃ interface and/or in the Al₂O₃ layer.