SCIENTIA SINICA Informationis, Volume 50 , Issue 6 : 892-912(2020) https://doi.org/10.1360/SSI-2019-0248

Recent progress on optoelectronic synaptic devices

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  • ReceivedNov 18, 2019
  • AcceptedDec 19, 2019
  • PublishedMay 25, 2020


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  • Figure 1

    (Color online) (a) Schematics of a biological synapse [38]@Copyright 2016 WILEY-VCH Verlag GmbH & Co. KGaA; (b) Schematics of artificial synaptic devices with 2 terminals or 3 terminals

  • Figure 2

    (Color online) (a) Dependence of the $\Delta$PSC amplitudes on gate voltage for a synaptic device based on graphene hybrid phototransistor; (b) dependence of $\Delta$IPSC and $\Delta$EPSC on spike duration for the graphene hybrid phototransistor [44]@copyright 2017 IOP Publishing Ltd.; (c) dependence of the EPSC on drain voltage for a optoelectronic neuromorphic device based on pn-junction-decorated oxide thin-film transistor [45]@Copyright 2019 Elsevier Ltd.; (d) dependence of the EPSC on photonic pulse intensity for an all-oxide-based highly transparent photonic synapse [46]@Copyright 2018 American Chemical Society; (e) dependence of EPSC and relaxation time on pulse width at different light intensities for a MoO$_{x}$optoelectronic resistive random access memory [47]@Copyright 2019 Springer Nature; (f) dependence of the EPSC on the duration time of the laser spikes with different wavelengths for the Si-NC/WSe$_{2}$synaptic device [48]@Copyright 2018 IEEE

  • Figure 3

    (Color online) (a) Paired-pulse facilitation at the granule cell to Purkinje cell synapse [62]@Copyright 1996 Society for Neuroscience; (b) the PPF behavior of a graphene hybrid phototransistor [63]@Copyright 2016 Optical Society of America; (c) PPF behaviors of an InAs nanowire phototransistor [64]@Copyright 2018 IOP Publishing Ltd.; (d) dependence of the PPF index on pulse intervals for the laser spikes with different gate biases [65]@Copyright 2018 IEEE; (e) dependence of the PPF index on pulse intervals for the laser spikes with different light pulse intensities; (f) dependence of the PPF index on pulse intervals for the laser spikes with different wavelengths [66]@Copyright 2018 WILEY-VCH Verlag GmbH & Co. KGaA

  • Figure 4

    Schematic illustration of a typical memory model in psychology [70]@Copyright 2017 WILEY-VCH Verlag GmbH & Co. KGaA

  • Figure 5

    (Color online) Channel conductance change ($\Delta~G$ as a function of (a) presynaptic light pulse number, protectłinebreak (b) presynaptic light pulse intensity, and (c) presynaptic light pulse width [76]@Copyright 2019 WILEY-VCH Verlag GmbH & Co. KGaA

  • Figure 6

    (Color online) (a) STDP measurements in hippocampal glutamatergic synapses [39]@Copyright 1998 Society for Neuroscience; (b) four forms of STDP [89]@Copyright 2010 Shouval, Wang and Wittenberg

  • Figure 7

    (Color online) STDP learning behaviors mimicked on a deep-ultraviolet-triggered InZnO phototransistors [93]@Copyright 2018 AIP Publishing. (a) and (b) The asymmetric Hebbian learning rule; (c) and (d) the symmetric Hebbian learning rule and the waveform of optical/electrical spike for achieving them

  • Figure 8

    (Color online) (a) Biological experience-dependent plasticity in the visual cortex [96]@Copyright 1996 Springer Nature; (b) EPSCs recorded in response to the stimulus train with different frequencies; (c) ${\Delta}S$ plotted as a function of presynaptic spike frequency [97]@Copyright 2019 The Royal Society of Chemistry; (d) ${\Delta}S$ after 50 light pulses plotted as a function of gate voltage [65]@Copyright 2018 IEEE

  • Figure 9

    (Color online) Schematic of calculation methods for energy consumption of single synaptic event in optoelectronic synaptic devices. (a) The 1st method; (b) the 2nd method; (c) the 3rd method

  • Figure 10

    (Color online) (a) Energy-band diagrams of an IGZO-based photonic neuromorphic device in dark conditions and under illumination; (b) the relationship between the activation energies ($E_{\rm~a}$) and the relaxation time constant for various AOSs [70]@Copyright 2017 WILEY-VCH Verlag GmbH & Co. KGaA; (c) the photonic operation concept of an IGZO-based TFT device; (d) illustration of atomic structures for N$\rm_R$ In$\rm_H$ and Ga$\rm_H$IGZO films [106]@Copyright 2018 WILEY-VCH Verlag GmbH & Co. KGaA; (e) schematic energy-band diagrams for the formation of ${{\rm~V}_{\rm~O}}^{2+}$and ${{\rm~V}_{\rm~O}}^{2+}$/${\rm~O}_{\rm~i}$; (f) schematic energy vs. lattice relaxation curves of the (0) and (2+) charge state in $\alpha$- and $\beta$-type configurations (the dashed and solid arrowline denotes the ionization and recovery process, respectively);protectłinebreak (g) the EPSC of IGZO, SnO$_x$/IGZO and PP/SnO$_x$/IGZO devices after light stimulation [45]@Copyright 2019 Elsevier Ltd.

  • Figure 11

    (Color online) (a) Schematic operation mechanism of an artificial optoelectronicsynapse based on ITO/Nb:SrTiO$_3$heterojunction; (b) mimicry of human visual memory [107]@Copyright 2019 American Chemical Society

  • Figure 12

    (Color online) (a) The mechanism responsible for the synaptic behavior of the CdS/MWCNT-based device [75]@Copyright 2016 WILEY-VCH Verlag GmbH & Co. KGaA; (b) schematic of a printed SWCNT phototransistor device under illumination of different light wavelengths; (c) low-pass filtering characteristics of the printed SWCNT transistors device [108]@Copyright 2019 American Chemical Society; (d) energy band diagram of excitation, thermalization, recombination, and trapping processes in the InAs nanowire phototransistor [64]@Copyright 2018 IOP Publishing Ltd.; (e) schematic of an array of Si-NC-based synaptic devices; (f) the STS curve, resulting for the Si-NC film measured at 77 K, has been shifted so that the Fermi level is at 0 V; (g) schematic model for the electronic structure and carrier behavior of Si NCs [100]@Copyright 2018 Elsevier Ltd.; (h) schematic of the Si-NC/WSe$_2$synaptic device structure [48]@Copyright 2018 IEEE

  • Figure 13

    (Color online) Neuromorphic computing simulation for image recognition. (a) Schematic of a taste aversion learning process for the treatment of alcoholism; (b) implementation of taste aversion learning with a synaptic Si-NC phototransistor; (c) example images in the MNIST database after the binarization with a pixel threshold of 50; (d) the architecture of the spiking neural network; (e) receptive fields of all output neurons in the network trained with the L/E$^+$STDP model; (f) receptive fields of all output neurons in the network trained with the E$^-$/E$^+$STDP model [101]@Copyright 2019 Elsevier Ltd.

  • Figure 14

    (Color online) (a) Mechanism of IGZO-based synaptic transistor under UV-light stimulation [109]@Copyright 2016 AIP Publishing; (b) schematic illustrations of the band diagram of the ZnO$_{1-x}$/AlO$_{y}$heterojunction [110]@Copyright 2018 American Chemical Society; (c) schematic diagram of a light-stimulated C8-BTBT synaptic transistors array; protectłinebreak (d) fabrication process of the T-shape transistors array; (e) dynamic learning and forgetting process of the T-shape synaptic transistors array [111]@Copyright 2018 American Chemical Society

  • Figure 15

    (Color online) (a) Mechanism of the IGZO-based EDL transistors [65]@Copyright 2018 IEEE; (b) mechanism of the MoS$_{2}$-based EDL transistors; (c) schematic of the photonic MoS$_{2}$synapse to function as both high-pass and low-pass photonic filters; (d) the spatiotemporal correlation effect; (e) the changes in synaptic weight ($\Delta~W$ as function of

  • Figure 16

    (Color online) Classical conditioning Pavlov's dog experiment emulated by MoS$_{2}$neuristors [112]@Copyright 2018 WILEY-VCH Verlag GmbH & Co. KGaA

  • Figure 17

    (Color online) (a) The time response of an NOR logic operation emulated by the graphene/SWCNTs hybrid phototransistor [44]@Copyright 2017 IOP Publishing Ltd.; (b) schematics of a two-terminal visible light transparent device based on ZnO/In$_{2}$O$_{3}$; (c) schematic illustrations of the working mechanism of the photonic synapse [46]@Copyright 2018 American Chemical Society; (d) endurance property of the light-programmed state and electric erased state of the photonic synapses based on inorganic perovskite quantum dots; (e) energy diagram of photonic synapses based on inorganic perovskite quantum dots during light programming operation and during electrical erasing operation under dark protectłinebreak condition [66]@Copyright 2018 WILEY-VCH Verlag GmbH & Co. KGaA