Photoelectric Dual-Mode Synergistically Stimulated Biometric Dielectric-Based IGZO Synaptic Transistors

In recent years, neuromorphic computing systems have demonstrated significant potential for application in the field of artificial intelligence (AI). In this domain, simulating synaptic behavior through a single electronic device is considered a critical step toward hardware implementation. However, most reported synaptic devices or neuromorphic devices lack environmental sustainability. This work proposes a degradable biocompatible gate dielectric material. By doping citric acid to enhance the electric double layer (EDL) characteristics of the gate dielectrics, we prepared methylcellulose (MC)-based amorphous indium gallium zinc oxide (a-IGZO) artificial synaptic transistors that exhibit good electrical properties using a simple fabrication method and low-temperature requirements. Additionally, by controlling the duration, amplitude, and quantity of the electric and light inputs of the presynaptic pulse, we successfully simulated basic synaptic functions, such as excitatory postsynaptic current (EPSC) induced by single pulses and paired-pulse facilitation (PPF) resulting from multiple pulses. The prepared MC-based a-IGZO nonannealed devices exhibited a certain photoresponse, and the transformation from short-term plasticity (STP) to long-term plasticity (LTP) was achieved by utilizing the persistent photoconductivity (PPC) characteristics of the amorphous oxides, demonstrating that our device possesses favorable long-term memory (LTM) characteristics. Finally, we conducted the Pavlov dog experiment to effectively simulate the behavior of associative learning, thereby providing potential applications for “green” neuromorphic devices.