Ultrathin SrTiO3-based oxide memristor with both drift and diffusive dynamics as versatile synaptic emulators for neuromorphic computing
doi: 10.1088/2752-5724/ace3dc
-
Abstract: Artificial synapses are electronic devices that simulate important functions of biological synapses, and therefore are the basic components of artificial neural morphological networks for brain-like computing. One of the most important objectives for developing artificial synapses is to simulate the characteristics of biological synapses as much as possible, especially their self-adaptive ability to external stimuli. Here, we have successfully developed an artificial synapse with multiple synaptic functions and highly adaptive characteristics based on a simple SrTiO3/Nb: SrTiO3 heterojunction type memristor. Diverse functions of synaptic learning, such as short-term/long-term plasticity (STP/LTP), transition from STP to LTP, learning-forgetting-relearning behaviors, associative learning and dynamic filtering, are all bio-realistically implemented in a single device. The remarkable synaptic performance is attributed to the fascinating inherent dynamics of oxygen vacancy drift and diffusion, which give rise to the coexistence of volatile- and nonvolatile-type resistive switching. This work reports a multi-functional synaptic emulator with advanced computing capability based on a simple heterostructure, showing great application potential for a compact and low-power neuromorphic computing system.
-
Key words:
- memristor /
- artificial synapse /
- synaptic plasticity /
- associative learning /
- learning-experience
-
Figure 1. Device structure and the basic electrical characterization. (a) Schematic diagram of Au/Cr/STO/NSTO device. (b) I-V characteristic under positive and negative bias. (c) R-V loops measured with different pulse width. (d) Measured and fitted I-V curves of HRS and LRS for the device. (e) LRS resistance as a function of electrode sizes. (f) Schematic diagram of oxygen vacancy migration and the corresponding energy band diagrams for LRS and HRS. (g) Endurance behavior.
Figure 2. Short-term plasticity of the Au/Cr/STO/NSTO artificial synapse. (a) EPSC triggered by a single pulse of 0.9 V, 100
s. (b) The EPSCs triggered by a pair of positive pulses of 1 V, 100 s. (c) The varying of PPF as a function of the relative pulse interval t. (d) The EPSCs triggered by a pair of negative pulses of -1.2 V, 1 ms. (e) The variation of PPD as a function of t. (f) PTP as a function of t, and (g) EPSC under ten pulse stimulations with different pulse frequencies. Figure 3. Long-term plasticity of the Au/Cr/STO/NSTO artificial synapse. (a) and (b) Long-term potentiation and long-term depression, respectively. EPSC response to the pulse sequence with different (c) pulse amplitude, (d) pulse width, (e) pulse interval, and (f) pulse number. (g) The EPSC triggered by 30 consecutive pulses with different frequencies. (h) Frequency dependence of EPSC gain A30/A1 and the fitting results by the sigmoidal-shaped function.
Figure 4. The learning-forgetting-relearning process achieved within a single Au/Cr/STO/NSTO memristor. (a), (c) and (e) Demonstrate the first, second and third learning stage, while (b), (d) and (f) give the first, second and third forgetting process. The amplitude and duration of the voltage pulses are 0.8 V and 100
s, respectively. The conductance responses are monitored with a small voltage of 0.1 V. -
[1] Wang J R, Zhuge F 2019 Memristive synapses for brain-inspired computing Adv. Mater. Technol. 4 1800544 doi: 10.1002/admt.201800544 [2] Xi F B, Han Y, Liu M S, Bae J H, Tiedemann A, Grützmacher D, Zhao Q T 2021 Artificial synapses based on ferroelectric Schottky barrier field-effect transistors for neuromorphic applications ACS Appl. Mater. Interfaces 13 32005-12 doi: 10.1021/acsami.1c07505 [3] Zhang H Z, Ju X, Yew K S, Ang D S 2020 Implementation of simple but powerful trilayer oxide-based artificial synapses with a tailored bio-synapse-like structure ACS Appl. Mater. Interfaces 12 1036-45 doi: 10.1021/acsami.9b17026 [4] Pereda A E 2014 Electrical synapses and their functional interactions with chemical synapses Nat. Rev. Neurosci. 15 250-63 doi: 10.1038/nrn3708 [5] Chang T, Jo S H, Lu W 2011 Short-term memory to long-term memory transition in a nanoscale memristor ACS Nano 5 7669-76 doi: 10.1021/nn202983n [6] Yang S T, et al 2022 High-performance neuromorphic computing based on ferroelectric synapses with excellent conductance linearity and symmetry Adv. Funct. Mater. 32 2202366 doi: 10.1002/adfm.202202366 [7] Kuzum D, Jeyasingh R G D, Lee B, Wong H S P 2012 Nanoelectronic programmable synapses based on phase change materials for brain-inspired computing Nano Lett. 12 2179-86 doi: 10.1021/nl201040y [8] Sokolov A S, Jeon Y R, Kim S, Ku B, Choi C 2019 Bio-realistic synaptic characteristics in the cone-shaped ZnO memristive device NPG Asia Mater. 11 1-15 doi: 10.1038/s41427-018-0105-7 [9] Ohno T, Hasegawa T, Tsuruoka T, Terabe K, Gimzewski J K, Aono M 2011 Short-term plasticity and long-term potentiation mimicked in single inorganic synapses Nat. Mater. 10 591-5 doi: 10.1038/nmat3054 [10] Nayak A, Ohno T, Tsuruoka T, Terabe K, Hasegawa T, Gimzewski J K, Aono M 2012 Controlling the synaptic plasticity of a Cu2S gap-type atomic switch Adv. Funct. Mater. 22 3606-13 doi: 10.1002/adfm.201200640 [11] Li J K, Ge C, Du J Y, Wang C, Yang G Z, Jin K J 2020 Reproducible ultrathin ferroelectric domain switching for high-performance neuromorphic computing Adv. Mater. 32 1905764 doi: 10.1002/adma.201905764 [12] Yang Y, Wen J, Guo L Q, Wan X, Du P F, Feng P, Shi Y, Wan Q 2016 Long-term synaptic plasticity emulated in modified graphene oxide electrolyte gated IZO-based thin-film transistors ACS Appl. Mater. Interfaces 8 30281-6 doi: 10.1021/acsami.6b08515 [13] John R A, et al 2022 Reconfigurable halide perovskite nanocrystal memristors for neuromorphic computing Nat. Commun. 13 2074 doi: 10.1038/s41467-022-29727-1 [14] Wang Z R, et al 2017 Memristors with diffusive dynamics as synaptic emulators for neuromorphic computing Nat. Mater. 16 101-8 doi: 10.1038/nmat4756 [15] Midya R, et al 2019 Artificial neural network (ANN) to spiking neural network (SNN) converters based on diffusive memristors Adv. Electron. Mater. 5 1900060 doi: 10.1002/aelm.201900060 [16] Li J K, Li N, Ge C, Huang H Y, Sun Y W, Gao P, He M, Wang C, Yang G Z, Jin K J 2019 Giant electroresistance in ferroionic tunnel junctions iScience 16 368-77 doi: 10.1016/j.isci.2019.05.043 [17] Yang R, Huang H M, Guo X 2019 Memristive synapses and neurons for bioinspired computing Adv. Electron. Mater. 5 1900287 doi: 10.1002/aelm.201900287 [18] Liu G, Wang C, Zhang W B, Pan L, Zhang C C, Yang X, Fan F, Chen Y, Li R W 2016 Organic biomimicking memristor for information storage and processing applications Adv. Electron. Mater. 2 1500298 doi: 10.1002/aelm.201500298 [19] Yang J T, Ge C, Du J Y, Huang H Y, He M, Wang C, Lu H B, Yang G Z, Jin K J 2018 Artificial synapses emulated by an electrolyte-gated tungsten-oxide transistor Adv. Mater. 30 1801548 doi: 10.1002/adma.201801548 [20] Liu Y H, Zhu L Q, Feng P, Shi Y, Wan Q 2015 Freestanding artificial synapses based on laterally proton-coupled transistors on chitosan membranes Adv. Mater. 27 5599-604 doi: 10.1002/adma.201502719 [21] Shen Z H, Li W H, Tang X G, Hu J, Wang K Y, Jiang Y P, Guo X B 2022 An artificial synapse based on Sr(Ti, Co)O3 films Mater. Today Commun. 33 104754 doi: 10.1016/j.mtcomm.2022.104754 [22] Ren Z Y, Zhu L Q, Guo Y B, Long T Y, Yu F, Xiao H, Lu H L 2020 Threshold tunable spike rate dependent plasticity originated from interfacial proton gating for pattern learning and memory ACS Appl. Mater. Interfaces 12 7833-9 doi: 10.1021/acsami.9b22369 [23] Yin L, Huang W, Xiao R L, Peng W B, Zhu Y Y, Zhang Y Q, Pi X D, Yang D 2020 Optically stimulated synaptic devices based on the hybrid structure of silicon nanomembrane and perovskite Nano Lett. 20 3378-87 doi: 10.1021/acs.nanolett.0c00298 [24] Zhao L, et al 2020 An artificial optoelectronic synapse based on a photoelectric memcapacitor Adv. Electron. Mater. 6 1900858 doi: 10.1002/aelm.201900858 [25] Lao J, Xu W, Jiang C L, Zhong N, Tian B B, Lin H C, Luo C H, Sejdic J T, Peng H, Duan C G 2021 Artificial synapse based on organic-inorganic hybrid perovskite with electric and optical modulation Adv. Electron. Mater. 7 2100291 doi: 10.1002/aelm.202100291 -
mface3dcsupp1.docx