Photoelectric IGZO Electric-Double-Layer Transparent Artificial Synapses for Emotional State Simulation

Abstract

Here, a three-terminal optoelectronic synapse is simply fabricated based on chitosan (CS)/indium gallium zinc oxide (IGZO) with a combination of electrical and optical simulations, which successfully emulates the key features of biological synapses of learning and memory behavior, in particular the reproduction of the typical Hebbian spike-time dependence plasticity (STDP) rule and 2794.6% of the maximum paired-pulse facilitation (PPF) under electrical stimulation. Creating an analogy to device characteristics, more importantly, memory behavior was studied with changes of the human internal state (comfortable and uncomfortable) and the external environment stimuli (quiet and noise); this showed the best results, longest forgetting time and good memory effect, under a comfortable internal state and a quiet environment. Our results suggest that solution-gated IGZO-based electric-double-layer transparent phototransistor transistors could act as platforms for synaptic and human behavior simulation.

Amorphous InGaZnO (a-IGZO) Synaptic Transistor for Neuromorphic Computing

“…However, the mobile ions can penetrate the channel under the high gate bias, inducing LTP characteristics. Tremendous efforts have been made to develop the EDL-based IGZO TFTs for electronic- and/or photonic-synaptic devices using polymer, , ion gel, and solid-state electrolyte. − Artificial optoelectronic synapses using chitosan and sodium-incorporated Al 2 O 3 are introduced in the Advanced Application section. − As for a solid-state electrolyte, 0.269 fJ per spike, which is lower than that in the human brain (∼10 fJ), was demonstrated by an IZO/IGZO artificial electronic synaptic transistor with three terminals employing SiO 2 . A 30 nm-thick SiO 2 , prepared by the low-temperature plasma-enhanced atomic layer deposition (PEALD) at 200 °C, was used as an EDL gate dielectric.…”

“…The time constant in each state was determined at the point where the normalized EPSC/IPSC amplitude after the removal of electrical stimulation reaches half of the peak values. Reprinted with permission from ref . Copyright 2019 American Chemical Society.…”

Surface passivation engineering approach to fluoroacrylate-incorporated polytetrafluoroethylene for highly reliable a-IGZO TFTs

“…[6][7][8] a-IGZO has superior compatibility with various transparent backplanes and highperformance optical device applications because of its high transparency in the whole visible spectrum. 9,10 On the other hand, the electrical stress stability and equipment environmental adaptability of the above-mentioned electronic applications have been challenged by the lengthy wearable status and complex environment. In particular, extensive research has been devoted to providing appropriate solutions for the reliability and stability issues of IGZO-based TFT devices.…”

“…6–8 a-IGZO has superior compatibility with various transparent backplanes and high-performance optical device applications because of its high transparency in the whole visible spectrum. 9,10…”

Ultralow Light‐Power Consuming Photonic Synapses Based on Ultrasensitive Perovskite/Indium‐Gallium‐Zinc‐Oxide Heterojunction Phototransistors

“…IGZO has been recognized as a premium channel material due to its high mobility, low processing-temperature, and good compatibility with industrial manufacturing. [25][26][27] In addition, perovskite nanocrystals or quantum dots stand out with a high quantum yield, efficient photon absorption and excellent optical tunability. [28][29][30] With this heterostructure combining the merits from both IGZO and perovskite PNCs, the phototransistor devices demonstrate outstanding photodetection performance in terms of high photoresponsivity (4.18 × 10 5 A W -1 ) and high photodetectivity (1.97 × 10 17 Jones) at the ultralow detectable light power density (0.52 nW cm -2 ), which lays good foundation for obtaining high performance light-stimulated ASDs.…”