Synaptic Behaviors Mimicked in Flexible Oxide-Based Transistors on Plastic Substrates

Abstract

In the human brain, synapses are the crucial connective parts between neurons, which endow neurons with significant computational abilities. Here, indium-zinc-oxide (IZO) based flexible synaptic transistors are fabricated on a plastic substrate by a simple self-assembly method. Proton conducting phosphorus-doped nanogranular SiO 2 electrolyte is used as the gate dielectric. Excitatory postsynaptic current, paired-pulse facilitation, and long-term memory are mimicked in the flexible artificial synapses. Such IZO-based flexible electronic synapses are promising for building neuromorphic systems. Index Terms-Flexible synaptic transistors, nanogranularSiO 2 electrolyte, paired-pulse facilitation (PPF).

Nanoionics-Based Three-Terminal Synaptic Device Using Zinc Oxide

“…Transparent conducting oxide (TCO) based synaptic devices hold great promise in realising energy efficient synaptic operation and spike timing dependent plasticity and short-term to long-term memory transitions have been demonstrated using Indium Zinc Oxide thin film transistors with nanogranular Silicon dioxide based proton conductor films as insulators. [31][32][33] The main drawback of such synaptic devices are the requirements of humidity to function as a synaptic FET, where the proton conductivity in the phosphorus-doped nanogranular SiO2 films is facilitated by absorbed water molecules in the nanoporous film. 33,34 Short term synaptic plasticity is demonstrated with aqueous gated Indium Gallium Zinc oxide (IGZO) synaptic devices using water and salt as gate electrolyte.…”

Flexible Ionic‐Electronic Hybrid Oxide Synaptic TFTs with Programmable Dynamic Plasticity for Brain‐Inspired Neuromorphic Computing

“…More recently, three‐terminal devices have been demonstrated to mimic biological synaptic functions such as paired pulse facilitation (PPF), spike‐duration‐dependent plasticity (SDDP), and dynamic filtering . Three‐terminal devices, commonly called synaptic transistors, offer the advantage of concurrently actualizing processing and memory functions, since the additional gate electrode can control the conductance between the other two electrodes, thereby simplifying the learning scheme and negating the need for complex synchronizing algorithms …”

Simulation of Laterally Coupled InGaZnO4-Based Electric-Double-Layer Transistors for Synaptic Electronics

“…Specially, ionic/electronic hybrid transistor has emerged as a promising candidate for artificial synapse [5], [6]. Recently, our group also reported indium-zinc-oxide synaptic transistors gated by inorganic electrolytes [7], [8]. In these synaptic transistors, gate pulses can change the ion distribution in the electrolyte, which can modulate the carrier concentration or induce an electrochemical doping in the channel layer.…”