To address the increasing demand for massive data storage and processing,brain-inspired neuromorphic comput-ing systems based on artificial synaptic devices have been actively developed in recent years.Among the vario...To address the increasing demand for massive data storage and processing,brain-inspired neuromorphic comput-ing systems based on artificial synaptic devices have been actively developed in recent years.Among the various materials inves-tigated for the fabrication of synaptic devices,silicon carbide(SiC)has emerged as a preferred choices due to its high electron mobility,superior thermal conductivity,and excellent thermal stability,which exhibits promising potential for neuromorphic applications in harsh environments.In this review,the recent progress in SiC-based synaptic devices is summarized.Firstly,an in-depth discussion is conducted regarding the categories,working mechanisms,and structural designs of these devices.Subse-quently,several application scenarios for SiC-based synaptic devices are presented.Finally,a few perspectives and directions for their future development are outlined.展开更多
Artificial sensory systems(ASS)are pivotal to next-generation extended reality technologies,now evolving into flexible platforms for comfortable wear and immersive user experiences,while ensuring high performance and ...Artificial sensory systems(ASS)are pivotal to next-generation extended reality technologies,now evolving into flexible platforms for comfortable wear and immersive user experiences,while ensuring high performance and operational reliability.To address these demands,metal-based nanoparticles(NPs),such as noble metal,oxide,and multi-elemental NPs,have been extensively incorporated into functional materials of sensory and synaptic devices due to their tunable optical,electrical,and chemical properties,enhancing sensory precision,stability,and environmental adaptability.However,traditional NP fabrication methods often involve complex processing,residual contaminants,and scalability issues,limiting their effectiveness in ASS applications.State-of-the-art laser ablation in liquids(LAL)presents a promising alternative,offering scalable production of surfactant-free NPs with customizable physicochemical properties,though their application in electronics remains underexplored.This review delves into the transformative potential of LAL-fabricated NPs in ASS,covering the fundamental mechanisms of LAL,the role of process parameters,the derivative strategies for size modulation,the diversity of metal-based NPs,their applications in sensory and synaptic devices,and the challenges and perspectives for meeting industrial standards.Bridging the gap between LAL and ASS is poised to revolutionize both industrial manufacturing and academic research by offering scalable solutions to overcome intrinsic tradeoffs between flexibility and performance,fostering innovations in human-centric,immersive electronics.展开更多
Neuromorphic computing systems can perform memory and computing tasks in parallel on artificial synaptic devices through simulating synaptic functions,which is promising for breaking the conventional von Neumann bottl...Neuromorphic computing systems can perform memory and computing tasks in parallel on artificial synaptic devices through simulating synaptic functions,which is promising for breaking the conventional von Neumann bottlenecks at hardware level.Artificial optoelectronic synapses enable the synergistic coupling between optical and electrical signals in synaptic modulation,which opens up an innovative path for effective neuromorphic systems.With the advantages of high mobility,optical transparency,ultrawideband tunability,and environmental stability,graphene has attracted tremendous interest for electronic and optoelectronic applications.Recent progress highlights the significance of implementing graphene into artificial synaptic devices.Herein,to better understand the potential of graphene-based synaptic devices,the fabrication technologies of graphene are first presented.Then,the roles of graphene in various synaptic devices are demonstrated.Furthermore,their typical optoelectronic applications in neuromorphic systems are reviewed.Finally,outlooks for development of synaptic devices based on graphene are proposed.This review will provide a comprehensive understanding of graphene fabrication technologies and graphene-based synaptic device for optoelectronic applications,also present an outlook for development of graphene-based synaptic device in future neuromorphic systems.展开更多
High-performance neuromorphic computing(i.e.,brain-like computing)is envisioned to seriously demand optoelectronically integrated artificial neural networks(ANNs)in the future.Optoelectronic synaptic devices are criti...High-performance neuromorphic computing(i.e.,brain-like computing)is envisioned to seriously demand optoelectronically integrated artificial neural networks(ANNs)in the future.Optoelectronic synaptic devices are critical building blocks for optoelectronically integrated ANNs.For the large-scale deployment of high-performance neuromorphic computing in the future,it would be advantageous to fabricate optoelectronic synaptic devices by using advanced silicon(Si)technologies.This calls for the development of Si-based optoelectronic synaptic devices.In this work we review the use of Si materials to make optoelectronic synaptic devices,which have either two-terminal or three-terminal structures.A series of important synaptic functionalities have been well mimicked by using these Si-based optoelectronic synaptic devices.We also present the outlook of using Si materials for optoelectronic synaptic devices.展开更多
With the rapid development of science and technology,the emergence of new application scenarios,such as robots,driverless vehicles and smart city,puts forward high requirements for artificial visual systems.Optoelectr...With the rapid development of science and technology,the emergence of new application scenarios,such as robots,driverless vehicles and smart city,puts forward high requirements for artificial visual systems.Optoelectronic synaptic devices have attracted much attention due to their advantages in sensing,memory and computing integration.In this work,via band structure engineering and heterostructure designing,a heterojunction optoelectronic synaptic device based on Cu doped with n-type SrTiO_(3)(Cu:STO)film combined with p-type CuAlO_(2)(CAO)thin film was fabricated.It is found surprisingly that the optoelectronic device based on Cu:STO/CAO p-n heterojunction exhibits a rapid response of 2 ms,and that it has a wideband response from visible to near-infrared(NIR)region.Additionally,a series of important synaptic functions,including excitatory postsynaptic current(EPSC),paired-pulse facilitation(PPF),shortterm potentiation(STP)to long-term potentiation(LTP)transition,learning experience behavior and image sharpening,have been successfully simulated on the device.More importantly,the performance of the device remains still stable and reliable after several months which were stored at room temperature and atmospheric pressure.Based on these advantages,the optoelectronic synaptic devices demonstrated here provide great potential in the new generation of artificial visual systems.展开更多
Ferroelectric capacitors hold great promise for non-volatile memory applications.However,the challenge lies in fabricating resistive switching devices with a high on/off ratio,excellent non-volatility,and a simple man...Ferroelectric capacitors hold great promise for non-volatile memory applications.However,the challenge lies in fabricating resistive switching devices with a high on/off ratio,excellent non-volatility,and a simple manufacturing process.Here,a novel approach is introduced by demonstrating the efficacy of the coupling effect between ferroelectric polarization and oxygen vacancy-based conductive filaments in Hf_(0.5)Zr_(0.5)O_(2)(HZO)films for the creation of non-volatile resistive switching memory devices,achieving an impressive on/off ratio of 6.8×10^(3) at+1.8 V.An in-depth exploration of the resistive switching mechanism is provided and subsequently the outstanding durability and retention characteristics of these devices for resistive switching is validated.Furthermore,the device's capacity to emulate non-volatile synaptic functionalities is assessed.Our results reveal that under pulsed conditions of 1 V/-2 V with 1µs pulses spaced 50 ms apart,the device can robustly achieve potentiation/depression synaptic plasticity,while exhibiting energy consumption(0.16 fJ for potentiation,0.12 fJ for depression)reduced by 1-2 orders of magnitude compared to biological synapses.This work holds significant value as a reference for the fabrication of energy-efficient,non-volatile memory and synaptic devices.展开更多
With the merits of non-contact,highly efficient,and parallel computing,optoelectronic synaptic devices combining sensing and memory in a single unit are promising for constructing neuromorphic computing and artificial...With the merits of non-contact,highly efficient,and parallel computing,optoelectronic synaptic devices combining sensing and memory in a single unit are promising for constructing neuromorphic computing and artificial visual chip.Based on this,a N:ZnO/MoS_(2)-heterostructured flexible optoelectronic synaptic device is developed in this work,and its capability in mimicking the synaptic behaviors is systemically investigated under the electrical and light signals.Versatile synaptic functions,including synaptic plasticity,long-term/short-term memory,and learning-forgetting-relearning property,have been achieved in this synaptic device.Further,an artificial visual memory system integrating sense and memory is emulated with the device array,and the visual memory behavior can be regulated by varying the light parameters.Moreover,the optoelectronic co-modulation behavior is verified by applying mixed electric and light signals to the array.In detail,a transient recovery property is discovered when the electric signals are applied in synergy during the decay of the light response,of which property facilitates the development of robust artificial visual systems.Furthermore,by superimposing electrical signals during the light response process,a differentiated response of the array is achieved,which can be used as a proof of concept for the color perception of the artificial visual system.展开更多
Artificial synaptic devices with the functions of emulating important biological synaptic behaviors are playing an increasingly important role in the development of neuromorphic computing systems.Single-walled carbon ...Artificial synaptic devices with the functions of emulating important biological synaptic behaviors are playing an increasingly important role in the development of neuromorphic computing systems.Single-walled carbon nanotubes(SWCNTs)with excellent electrical properties and high stability have been studied as active materials for synaptic devices.However,the performance of optical synaptic devices(OSDs)based on pure SWCNTs is limited by the weak light absorption property.Herein,bismuth triiodide(BiI_(3)),an environmentally stable and friendly optoelectronic material,is firstly combined with SWCNTs to fabricate OSDs with decent properties of perceiving and memorizing optical information.The OSDs can exhibit typical synaptic behaviors including excitatory postsynaptic current,paired-pulse facilitation,and short/long-term memory.Distinctively,the photoresponse of the OSD is independent of pulse light wavelength in the range of 365 to 650 nm,different from most of the previously reported OSDs,which usually have wavelength-dependent photo-response.Temperature-dependent photo-response behaviors of the devices are investigated.Importantly,the OSD without encapsulation holds good excitatory post-synaptic current(EPSC)behavior after being stored in the ambient environment for 170 days,indicating reliable environmental stability.Furthermore,an OSD array with nine synaptic devices is employed to mimic the human visual perception and memory functions.These results suggest the feasibility of BiI3/SWCNTs-based OSDs for the simulation of human visual memory.展开更多
The rapid development of artificial intelligence poses an urgent need for low-energy-consumption and small-sized artificial photonic synapses.Here,it is pretty novel to demonstrate a light-stimulated synaptic device b...The rapid development of artificial intelligence poses an urgent need for low-energy-consumption and small-sized artificial photonic synapses.Here,it is pretty novel to demonstrate a light-stimulated synaptic device based on a single(Al,Ga)N nanowire successfully.Thanks to the presence of vacancy defects in the single nanowire,the artificial synaptic device can simulate multiple functions of biological synapses under stimulation of both 310 and 365 nm light photons,including paired-pulse facilitation,spike timing dependent plasticity,and memory learning capabilities.The energy consumption of artificial synaptic device can be reduced as little as 5.58×10^(-13) J,which is close to that of the biological synapse in human brain.Furthermore,the synaptic device is demonstrated to have the high stability for both long-time stimulation and long-time storage.Based on the experimental conductance of long-term potentiation and long-term depression,the simulated three-layer neural network can achieve a high recognition rate of 92%after only 10 training epochs.With a brain-like behavior,the single-nanowire-based synaptic devices can promote the development of visual neuromorphic computing technology and artificial intelligence systems requiring ultralow energy consumption.展开更多
To meet a growing demand for information processing,brain-inspired neuromorphic devices have been intensively studied in recent years.As an important type of neuromorphic device,synaptic devices have attracted strong ...To meet a growing demand for information processing,brain-inspired neuromorphic devices have been intensively studied in recent years.As an important type of neuromorphic device,synaptic devices have attracted strong attention.Among all the kinds of materials explored for the fabrication of synaptic devices,semiconductor nanocrystals(NCs)have become one of the preferred choices due to their excellent electronic and optical properties.In this review,we first introduce the research background of synaptic devices based on semiconductor NCs and briefly present the basic properties of semiconductor NCs.Recent developments in the field of synaptic devices based on semiconductor NCs are then discussed according to the materials employed in the active layers of the devices.Finally,we discuss existing problems and challenges of synaptic devices based on semiconductor NCs.展开更多
Employing two-dimensional(2D)synaptic devices to develop a brain-inspired neuromorphic computing system is a promising approach to overcoming the limitations of the von Neumann architecture.However,isotropic 2D materi...Employing two-dimensional(2D)synaptic devices to develop a brain-inspired neuromorphic computing system is a promising approach to overcoming the limitations of the von Neumann architecture.However,isotropic 2D materials are predominantly utilized to fabricate synaptic devices.Research on inherently anisotropic 2D materials in synaptic devices remains scarce.Here,we report an intrinsically anisotropic material,CrSBr,which exhibits optoelectronic properties with significant angular dependence,achieving a carrier mobility ratio as high as 7.83between the a-axis and b-axis.Based on this,we couple the in-plane anisotropy into the synaptic device and construct CrSBr/WSe_(2)multi-terminal device.This device can be regulated by the gate voltage and laser,exhibiting storage and synaptic behaviors dependent on the a and b axes.Furthermore,we apply the synaptic property to achieve image recognition.Due to the anisotropic response to identical external stimulus,the a-axis conductance trend transits from nonlinear to approximately linear within the multi-terminal conductance framework.This multi-terminal synapse model achieves a recognition rate of up to 91%on the Fashion-MNIST database,significantly outperforming single-terminal recognition performance.Our work introduces a novel approach to anisotropic artificial synapses for simulated image recognition and establishes a foundation for developing AI systems with enhanced recognition rates.展开更多
Prosthetic devices designed to assist individuals with damaged or missing body parts have made significant strides,particularly with advancements in machine intelligence and bioengineering.Initially focused on movemen...Prosthetic devices designed to assist individuals with damaged or missing body parts have made significant strides,particularly with advancements in machine intelligence and bioengineering.Initially focused on movement assistance,the field has shifted towards developing prosthetics that function as seamless extensions of the human body.During this progress,a key challenge remains the reduction of interface artifacts between prosthetic components and biological tissues.Soft electronics offer a promising solution due to their structural flexibility and enhanced tissue adaptability.However,achieving full integration of prosthetics with the human body requires both artificial perception and efficient transmission of physical signals.In this context,synaptic devices have garnered attention as next-generation neuromorphic computing elements because of their low power consumption,ability to enable hardware-based learning,and high compatibility with sensing units.These devices have the potential to create artificial pathways for sensory recognition and motor responses,forming a“sensory-neuromorphic system”that emulates synaptic junctions in biological neurons,thereby connecting with impaired biological tissues.Here,we discuss recent developments in prosthetic components and neuromorphic applications with a focus on sensory perception and sensorimotor actuation.Initially,we explore a prosthetic system with advanced sensory units,mechanical softness,and artificial intelligence,followed by the hardware implementation of memory devices that combine calculation and learning functions.We then highlight the importance and mechanisms of soft-form synaptic devices that are compatible with sensing units.Furthermore,we review an artificial sensory-neuromorphic perception system that replicates various biological senses and facilitates sensorimotor loops from sensory receptors,the spinal cord,and motor neurons.Finally,we propose insights into the future of closed-loop neuroprosthetics through the technical integration of soft electronics,including bio-integrated sensors and synaptic devices,into prosthetic systems.展开更多
Neuromorphic computing simulates the operation of biological brain function for information processing and can potentially solve the bottleneck of the von Neumann architecture.This computing is realized based on memri...Neuromorphic computing simulates the operation of biological brain function for information processing and can potentially solve the bottleneck of the von Neumann architecture.This computing is realized based on memristive hardware neural networks in which synaptic devices that mimic biological synapses of the brain are the primary units.Mimicking synaptic functions with these devices is critical in neuromorphic systems.In the last decade,electrical and optical signals have been incorporated into the synaptic devices and promoted the simulation of various synaptic functions.In this review,these devices are discussed by categorizing them into electrically stimulated,optically stimulated,and photoelectric synergetic synaptic devices based on stimulation of electrical and optical signals.The working mechanisms of the devices are analyzed in detail.This is followed by a discussion of the progress in mimicking synaptic functions.In addition,existing application scenarios of various synaptic devices are outlined.Furthermore,the performances and future development of the synaptic devices that could be significant for building efficient neuromorphic systems are prospected.展开更多
Emulating synaptic plasticity in an artificial neural network is crucial to mimic the basic functions of the human brain.In this work,we report a new optoelectronic resistive random access memory(ORRAM)in a three-laye...Emulating synaptic plasticity in an artificial neural network is crucial to mimic the basic functions of the human brain.In this work,we report a new optoelectronic resistive random access memory(ORRAM)in a three-layer vertical heterostructure of graphene/Cd Se quantum dots(QDs)/graphene,which shows non-volatile multi-level optical memory under optical stimuli,giving rise to light-tunable synaptic behaviors.The optical non-volatile storage time is up to^450 s.The device realizes the function of multi-level optical storage through the interlayer changes between graphene and QDs.This work highlights the feasibility for applying two-dimensional(2D)materials in ORRAM and optoelectronic synaptic devices towards artificial vision.展开更多
The ionic environment of body fluids influences nervous functions for maintaining homeostasis in organisms and ensures normal perceptual abilities and reflex activities.Neural reflex activities,such as limb movements,...The ionic environment of body fluids influences nervous functions for maintaining homeostasis in organisms and ensures normal perceptual abilities and reflex activities.Neural reflex activities,such as limb movements,are closely associated with potassium ions(K+).In this study,we developed artificial synaptic devices based on ion concentration-adjustable gels for emulating various synaptic plasticities under different K+concentrations in body fluids.In addition to performing essential synaptic functions,potential applications in information processing and associative learning using short-and long-term plasticity realized using ion concentration-adjustable gels are presented.Artificial synaptic devices can be used for constructing an artificial neural pathway that controls artificial muscle reflex activities and can be used for image pattern recognition.All tests show a strong relationship with ion homeostasis.These devices could be applied to neuromorphic robots and human-machine interfaces.展开更多
The development of high-performance neuromorphic phototransistors is of paramount importance for image perception and depth memory learning.Here,based on metal-oxide heterojunction architecture,artificial synaptic pho...The development of high-performance neuromorphic phototransistors is of paramount importance for image perception and depth memory learning.Here,based on metal-oxide heterojunction architecture,artificial synaptic phototransistors with synaptic plasticity have been achieved,demonstrating an artificial synapse that integrates central and optic nerve functions.Thanks to the sensitive light-detection properties,the optical power consumption of such photonic artificial synapses can be as low as 22 picojoules,which is extremely competitive compared with other pure metal oxide photoelectric synapses ever reported.What is more,owing to its good short-term(STP)and tunable amplitude-frequency characteristics,the as-constructed device can function as a biomimetic high-pass filter for picture edge detection.Dual-mode synaptic modulation has been performed,combining photonic pulse with gate voltage stimulus.After photoelectric-synergistic modulation,the high synaptic weights enable the device to simulate complex neural learning rules for neuromorphic applications,including gesture recognition,image perception in the visual system,and classically conditioned reflexes.These results suggest that the current oxide-based heterojunction architecture displays potential application in future multifunction neuromorphic devices and systems.展开更多
A unique optoelectronic synaptic device has been developed,leveraging the negative photoconductance property of a single-crystal material system called Cs2CoCl4.This device exhibits a simultaneous volatile resistive s...A unique optoelectronic synaptic device has been developed,leveraging the negative photoconductance property of a single-crystal material system called Cs2CoCl4.This device exhibits a simultaneous volatile resistive switching response and sensitivity to optical stimuli,positioning Cs2CoCl4 as a promising candidate for optically enhanced neuromorphicapplications.展开更多
Synaptic devices that merge memory and processing functions into one unit have broad application potentials in neuromorphic computing, soft robots, and humanmachine interfaces. However, most previously reported synapt...Synaptic devices that merge memory and processing functions into one unit have broad application potentials in neuromorphic computing, soft robots, and humanmachine interfaces. However, most previously reported synaptic devices exhibit fixed performance once been fabricated,which limits their application in diverse scenarios. Here, we report floating-gate photosensitive synaptic transistors with charge-trapping perovskite quantum dots(PQDs) and atomic layer deposited(ALD) Al_(2)O_(3) tunneling layers, which exhibit typical synaptic behaviors including excitatory postsynaptic current(EPSC), pair-pulse facilitation and dynamic filtering characteristics under both electrical or optical signal stimulation. Further, the combination of the high-quality Al2O3 tuning layer and highly photosensitive PQDs charge-trapping layer provides the devices with extensively tunable synaptic performance under optical and electrical co-modulation. Applying light during electrical modulation can significantly improve both the synaptic weight changes and the nonlinearity of weight updates, while the memory effect under light modulation can be obviously adjusted by the gate voltage.The pattern learning and forgetting processes for "0" and "1"with different synaptic weights and memory times are further demonstrated in the device array. Overall, this work provides synaptic devices with tunable functions for building complex and robust artificial neural networks.展开更多
The quantum-dot light-emitting diodes(QLEDs)that emit near-infrared(NIR)light may be important optoelectronic synaptic devices for the realization of artificial neural networks with complete optoelectronic integration...The quantum-dot light-emitting diodes(QLEDs)that emit near-infrared(NIR)light may be important optoelectronic synaptic devices for the realization of artificial neural networks with complete optoelectronic integration.To improve the performance of NIR QLEDs,we take advantage of their low-energy light emission to explore the use of poly(3-hexylthiophene)(P3 HT)as the hole transport layer(HTL).P3 HT has one of the highest hole mobilities among organic semiconductors and essentially does not absorb NIR light.The usage of P3 HT as the HTL indeed significantly mitigates the imbalance of carrier injection in NIR QLEDs.With the additional incorporation of an interlayer of poly[9,9-bis(3’-(N,N-dimethylamino)propyl)-2,7-flourene]-alt-2,7-(9,9-dioctylfluorene)],P3 HT obviously improves the performance of NIR QLEDs.As electroluminescent synaptic devices,these NIR QLEDs exhibit important synaptic functionalities such as short-and long-term plasticity,and may be employed for image recognition.展开更多
Artificial synaptic devices hold great potential in building neuromorphic computers.Due to the unique morphological features,twodimensional organic semiconductors at the monolayer limit show interesting properties whe...Artificial synaptic devices hold great potential in building neuromorphic computers.Due to the unique morphological features,twodimensional organic semiconductors at the monolayer limit show interesting properties when acting as the active layers for organic field-effect transistors.Here,organic synaptic transistors are prepared with 1,4-bis((5’-hexyl-2,2’-bithiophen-5-yl)ethyl)benzene(HTEB)monolayer molecular crystals.Functions similar to biological synapses,including excitatory postsynaptic current(EPSC),pair-pulse facilitation,and short/long-term memory,have been realized.The synaptic device achieves the minimum power consumption of 4.29 fJ at low drain voltage of−0.01 V.Moreover,the HTEB synaptic device exhibits excellent long-term memory with 109 s EPSC estimated retention time.Brain-like functions such as dynamic learning-forgetting process and visual noise reduction are demonstrated by nine devices.The unique morphological features of the monolayer molecular semiconductors help to reveal the device working mechanism,and the synaptic behaviors of the devices can be attributed to oxygen induced energy level.This work shows the potential of artificial neuroelectronic devices based on organic monolayer molecular crystals.展开更多
基金supported by the Natural Science Foundation of Zhejiang Province(Grant No.LQ24F040007)the National Natural Science Foundation of China(Grant No.U22A2075)the Opening Project of State Key Laboratory of Polymer Materials Engineering(Sichuan University)(Grant No.sklpme2024-1-21).
文摘To address the increasing demand for massive data storage and processing,brain-inspired neuromorphic comput-ing systems based on artificial synaptic devices have been actively developed in recent years.Among the various materials inves-tigated for the fabrication of synaptic devices,silicon carbide(SiC)has emerged as a preferred choices due to its high electron mobility,superior thermal conductivity,and excellent thermal stability,which exhibits promising potential for neuromorphic applications in harsh environments.In this review,the recent progress in SiC-based synaptic devices is summarized.Firstly,an in-depth discussion is conducted regarding the categories,working mechanisms,and structural designs of these devices.Subse-quently,several application scenarios for SiC-based synaptic devices are presented.Finally,a few perspectives and directions for their future development are outlined.
基金supported by the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(Grant Nos.RS-2024-00403639 and RS2024-00411904)。
文摘Artificial sensory systems(ASS)are pivotal to next-generation extended reality technologies,now evolving into flexible platforms for comfortable wear and immersive user experiences,while ensuring high performance and operational reliability.To address these demands,metal-based nanoparticles(NPs),such as noble metal,oxide,and multi-elemental NPs,have been extensively incorporated into functional materials of sensory and synaptic devices due to their tunable optical,electrical,and chemical properties,enhancing sensory precision,stability,and environmental adaptability.However,traditional NP fabrication methods often involve complex processing,residual contaminants,and scalability issues,limiting their effectiveness in ASS applications.State-of-the-art laser ablation in liquids(LAL)presents a promising alternative,offering scalable production of surfactant-free NPs with customizable physicochemical properties,though their application in electronics remains underexplored.This review delves into the transformative potential of LAL-fabricated NPs in ASS,covering the fundamental mechanisms of LAL,the role of process parameters,the derivative strategies for size modulation,the diversity of metal-based NPs,their applications in sensory and synaptic devices,and the challenges and perspectives for meeting industrial standards.Bridging the gap between LAL and ASS is poised to revolutionize both industrial manufacturing and academic research by offering scalable solutions to overcome intrinsic tradeoffs between flexibility and performance,fostering innovations in human-centric,immersive electronics.
基金the National Natural Science Foundation of China (Grant No. 61974093)Guangdong Basic and Applied Basic Research Foundation (Grant No. 2023A1515012479)+2 种基金Guangdong Provincial Department of Science and Technology (Grant No. 2020A1515110883)the Science and Technology Innovation Commission of Shenzhen (Grant Nos. RCYX20200714114524157 and JCYJ20220818100206013)NTUT-SZU Joint Research Program (Grant No. NTUT-SZU-112-02)
文摘Neuromorphic computing systems can perform memory and computing tasks in parallel on artificial synaptic devices through simulating synaptic functions,which is promising for breaking the conventional von Neumann bottlenecks at hardware level.Artificial optoelectronic synapses enable the synergistic coupling between optical and electrical signals in synaptic modulation,which opens up an innovative path for effective neuromorphic systems.With the advantages of high mobility,optical transparency,ultrawideband tunability,and environmental stability,graphene has attracted tremendous interest for electronic and optoelectronic applications.Recent progress highlights the significance of implementing graphene into artificial synaptic devices.Herein,to better understand the potential of graphene-based synaptic devices,the fabrication technologies of graphene are first presented.Then,the roles of graphene in various synaptic devices are demonstrated.Furthermore,their typical optoelectronic applications in neuromorphic systems are reviewed.Finally,outlooks for development of synaptic devices based on graphene are proposed.This review will provide a comprehensive understanding of graphene fabrication technologies and graphene-based synaptic device for optoelectronic applications,also present an outlook for development of graphene-based synaptic device in future neuromorphic systems.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2017YFA0205704 and 2018YFB2200101)the National Natural Science Foundation of China(Grant Nos.91964107 and 61774133)+2 种基金the Fundamental Research Funds for the Central Universities,China(Grant No.2018XZZX003-02)the National Natural Science Foundation of China for Innovative Research Groups(Grant No.61721005)the Zhejiang University Education Foundation Global Partnership Fund.
文摘High-performance neuromorphic computing(i.e.,brain-like computing)is envisioned to seriously demand optoelectronically integrated artificial neural networks(ANNs)in the future.Optoelectronic synaptic devices are critical building blocks for optoelectronically integrated ANNs.For the large-scale deployment of high-performance neuromorphic computing in the future,it would be advantageous to fabricate optoelectronic synaptic devices by using advanced silicon(Si)technologies.This calls for the development of Si-based optoelectronic synaptic devices.In this work we review the use of Si materials to make optoelectronic synaptic devices,which have either two-terminal or three-terminal structures.A series of important synaptic functionalities have been well mimicked by using these Si-based optoelectronic synaptic devices.We also present the outlook of using Si materials for optoelectronic synaptic devices.
基金financially supported by the National Science Funds for Excellent Young Scholars of China(No.61822106)the Natural Science Foundation of China(Nos.U19A2070,62074025)the National Key Research&Development Program(No.2020YFA0309200)。
文摘With the rapid development of science and technology,the emergence of new application scenarios,such as robots,driverless vehicles and smart city,puts forward high requirements for artificial visual systems.Optoelectronic synaptic devices have attracted much attention due to their advantages in sensing,memory and computing integration.In this work,via band structure engineering and heterostructure designing,a heterojunction optoelectronic synaptic device based on Cu doped with n-type SrTiO_(3)(Cu:STO)film combined with p-type CuAlO_(2)(CAO)thin film was fabricated.It is found surprisingly that the optoelectronic device based on Cu:STO/CAO p-n heterojunction exhibits a rapid response of 2 ms,and that it has a wideband response from visible to near-infrared(NIR)region.Additionally,a series of important synaptic functions,including excitatory postsynaptic current(EPSC),paired-pulse facilitation(PPF),shortterm potentiation(STP)to long-term potentiation(LTP)transition,learning experience behavior and image sharpening,have been successfully simulated on the device.More importantly,the performance of the device remains still stable and reliable after several months which were stored at room temperature and atmospheric pressure.Based on these advantages,the optoelectronic synaptic devices demonstrated here provide great potential in the new generation of artificial visual systems.
基金supported by the National Natu-ral Science Foundation of China(Nos.52250281,62204088 and 62174059)the Science and Technology Projects in Guangzhou(No.202201000008)+1 种基金the Guangdong Provincial Key Laboratory of Optical Information Materials and Technology(No.2017B030301007)the South China Normal University Youth Teacher Research and Training Fund(No.22KJ10).
文摘Ferroelectric capacitors hold great promise for non-volatile memory applications.However,the challenge lies in fabricating resistive switching devices with a high on/off ratio,excellent non-volatility,and a simple manufacturing process.Here,a novel approach is introduced by demonstrating the efficacy of the coupling effect between ferroelectric polarization and oxygen vacancy-based conductive filaments in Hf_(0.5)Zr_(0.5)O_(2)(HZO)films for the creation of non-volatile resistive switching memory devices,achieving an impressive on/off ratio of 6.8×10^(3) at+1.8 V.An in-depth exploration of the resistive switching mechanism is provided and subsequently the outstanding durability and retention characteristics of these devices for resistive switching is validated.Furthermore,the device's capacity to emulate non-volatile synaptic functionalities is assessed.Our results reveal that under pulsed conditions of 1 V/-2 V with 1µs pulses spaced 50 ms apart,the device can robustly achieve potentiation/depression synaptic plasticity,while exhibiting energy consumption(0.16 fJ for potentiation,0.12 fJ for depression)reduced by 1-2 orders of magnitude compared to biological synapses.This work holds significant value as a reference for the fabrication of energy-efficient,non-volatile memory and synaptic devices.
基金supported by the National Natural Science Foundation of China(No.62174068).
文摘With the merits of non-contact,highly efficient,and parallel computing,optoelectronic synaptic devices combining sensing and memory in a single unit are promising for constructing neuromorphic computing and artificial visual chip.Based on this,a N:ZnO/MoS_(2)-heterostructured flexible optoelectronic synaptic device is developed in this work,and its capability in mimicking the synaptic behaviors is systemically investigated under the electrical and light signals.Versatile synaptic functions,including synaptic plasticity,long-term/short-term memory,and learning-forgetting-relearning property,have been achieved in this synaptic device.Further,an artificial visual memory system integrating sense and memory is emulated with the device array,and the visual memory behavior can be regulated by varying the light parameters.Moreover,the optoelectronic co-modulation behavior is verified by applying mixed electric and light signals to the array.In detail,a transient recovery property is discovered when the electric signals are applied in synergy during the decay of the light response,of which property facilitates the development of robust artificial visual systems.Furthermore,by superimposing electrical signals during the light response process,a differentiated response of the array is achieved,which can be used as a proof of concept for the color perception of the artificial visual system.
基金supported by the National Natural Science Foundation of China(Nos.61822405,62074111)the Science&Technology Foundation of Shanghai(Nos.19JC1412402,20JC1415600)+2 种基金Shanghai Municipal Science and Technology Major Project(No.2021SHZDZX0100)Shanghai Municipal Commission of Science and Technology Project(No.19511132101)the support of the Fundamental Research Funds for the Central Universities.
文摘Artificial synaptic devices with the functions of emulating important biological synaptic behaviors are playing an increasingly important role in the development of neuromorphic computing systems.Single-walled carbon nanotubes(SWCNTs)with excellent electrical properties and high stability have been studied as active materials for synaptic devices.However,the performance of optical synaptic devices(OSDs)based on pure SWCNTs is limited by the weak light absorption property.Herein,bismuth triiodide(BiI_(3)),an environmentally stable and friendly optoelectronic material,is firstly combined with SWCNTs to fabricate OSDs with decent properties of perceiving and memorizing optical information.The OSDs can exhibit typical synaptic behaviors including excitatory postsynaptic current,paired-pulse facilitation,and short/long-term memory.Distinctively,the photoresponse of the OSD is independent of pulse light wavelength in the range of 365 to 650 nm,different from most of the previously reported OSDs,which usually have wavelength-dependent photo-response.Temperature-dependent photo-response behaviors of the devices are investigated.Importantly,the OSD without encapsulation holds good excitatory post-synaptic current(EPSC)behavior after being stored in the ambient environment for 170 days,indicating reliable environmental stability.Furthermore,an OSD array with nine synaptic devices is employed to mimic the human visual perception and memory functions.These results suggest the feasibility of BiI3/SWCNTs-based OSDs for the simulation of human visual memory.
基金The authors are grateful for the Key Research Program of Frontier Sciences,CAS(No.ZDBS-LY-JSC034)the Research Program of Scientific Instrument and Equipment of CAS(No.YJKYYQ20200073)+1 种基金the National Natural Science Foundation of China(No.62174172)The authors are thankful for the technical support from the Vacuum Interconnected Nanotech Workstation(Nano-X,No.F2309),Platform for Characterization&Test of SINANO,CAS.
文摘The rapid development of artificial intelligence poses an urgent need for low-energy-consumption and small-sized artificial photonic synapses.Here,it is pretty novel to demonstrate a light-stimulated synaptic device based on a single(Al,Ga)N nanowire successfully.Thanks to the presence of vacancy defects in the single nanowire,the artificial synaptic device can simulate multiple functions of biological synapses under stimulation of both 310 and 365 nm light photons,including paired-pulse facilitation,spike timing dependent plasticity,and memory learning capabilities.The energy consumption of artificial synaptic device can be reduced as little as 5.58×10^(-13) J,which is close to that of the biological synapse in human brain.Furthermore,the synaptic device is demonstrated to have the high stability for both long-time stimulation and long-time storage.Based on the experimental conductance of long-term potentiation and long-term depression,the simulated three-layer neural network can achieve a high recognition rate of 92%after only 10 training epochs.With a brain-like behavior,the single-nanowire-based synaptic devices can promote the development of visual neuromorphic computing technology and artificial intelligence systems requiring ultralow energy consumption.
基金Project supported by the National Key Research and Development Program of China(No.2018YFB2200101)the National Natural Science Foundation of China(Nos.91964107,U20A20209,and61721005)。
文摘To meet a growing demand for information processing,brain-inspired neuromorphic devices have been intensively studied in recent years.As an important type of neuromorphic device,synaptic devices have attracted strong attention.Among all the kinds of materials explored for the fabrication of synaptic devices,semiconductor nanocrystals(NCs)have become one of the preferred choices due to their excellent electronic and optical properties.In this review,we first introduce the research background of synaptic devices based on semiconductor NCs and briefly present the basic properties of semiconductor NCs.Recent developments in the field of synaptic devices based on semiconductor NCs are then discussed according to the materials employed in the active layers of the devices.Finally,we discuss existing problems and challenges of synaptic devices based on semiconductor NCs.
基金supported by the National Key R&D Program of China(No.2022YFA1203901)the National Natural Science Foundation of China(Nos.52450014,62174013,and 92265111)+1 种基金the National Science Foundation for Distinguished Young Scholars(No.JQ23007)the Beijing Natural Science Foundation(Nos.JQ23007 and L233003)
文摘Employing two-dimensional(2D)synaptic devices to develop a brain-inspired neuromorphic computing system is a promising approach to overcoming the limitations of the von Neumann architecture.However,isotropic 2D materials are predominantly utilized to fabricate synaptic devices.Research on inherently anisotropic 2D materials in synaptic devices remains scarce.Here,we report an intrinsically anisotropic material,CrSBr,which exhibits optoelectronic properties with significant angular dependence,achieving a carrier mobility ratio as high as 7.83between the a-axis and b-axis.Based on this,we couple the in-plane anisotropy into the synaptic device and construct CrSBr/WSe_(2)multi-terminal device.This device can be regulated by the gate voltage and laser,exhibiting storage and synaptic behaviors dependent on the a and b axes.Furthermore,we apply the synaptic property to achieve image recognition.Due to the anisotropic response to identical external stimulus,the a-axis conductance trend transits from nonlinear to approximately linear within the multi-terminal conductance framework.This multi-terminal synapse model achieves a recognition rate of up to 91%on the Fashion-MNIST database,significantly outperforming single-terminal recognition performance.Our work introduces a novel approach to anisotropic artificial synapses for simulated image recognition and establishes a foundation for developing AI systems with enhanced recognition rates.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.2020R1C1C1005567)supported by the NAVER Digital Bio Innovation Research Fund,funded by NAVER Corporation(Grant No.[37-2023-0040])+3 种基金supported by Institute of Information&communications Technology Planning&Evaluation(IITP)grant funded by the Korea government(MSIT)(No.2020-0-00261,Development of low power/low delay/self-power suppliable RF simultaneous information and power transfer system and stretchable electronic epineurium for wireless nerve bypass implementation)supported by Institute for Basic Science(IBS-R015-D1,IBSR015-D2)supported by a grant of the Korea-US Collaborative Research Fund(KUCRF)funded by the Ministry of Science and ICT and Ministry of Health&Welfare,Republic of Korea(Grant Number.RS-2024-00467213)。
文摘Prosthetic devices designed to assist individuals with damaged or missing body parts have made significant strides,particularly with advancements in machine intelligence and bioengineering.Initially focused on movement assistance,the field has shifted towards developing prosthetics that function as seamless extensions of the human body.During this progress,a key challenge remains the reduction of interface artifacts between prosthetic components and biological tissues.Soft electronics offer a promising solution due to their structural flexibility and enhanced tissue adaptability.However,achieving full integration of prosthetics with the human body requires both artificial perception and efficient transmission of physical signals.In this context,synaptic devices have garnered attention as next-generation neuromorphic computing elements because of their low power consumption,ability to enable hardware-based learning,and high compatibility with sensing units.These devices have the potential to create artificial pathways for sensory recognition and motor responses,forming a“sensory-neuromorphic system”that emulates synaptic junctions in biological neurons,thereby connecting with impaired biological tissues.Here,we discuss recent developments in prosthetic components and neuromorphic applications with a focus on sensory perception and sensorimotor actuation.Initially,we explore a prosthetic system with advanced sensory units,mechanical softness,and artificial intelligence,followed by the hardware implementation of memory devices that combine calculation and learning functions.We then highlight the importance and mechanisms of soft-form synaptic devices that are compatible with sensing units.Furthermore,we review an artificial sensory-neuromorphic perception system that replicates various biological senses and facilitates sensorimotor loops from sensory receptors,the spinal cord,and motor neurons.Finally,we propose insights into the future of closed-loop neuroprosthetics through the technical integration of soft electronics,including bio-integrated sensors and synaptic devices,into prosthetic systems.
基金This work was supported by the National Natural Science Foundation of China(11804166,U1732126,51872145)the China Postdoctoral Science Foundation(2018M630587)+1 种基金the Natural Science Foundation of Jiangsu Province(BK20200760,BK20191472)the Introduction of Talents Project of Nanjing University of Posts and Telecommunications(NY220097).
文摘Neuromorphic computing simulates the operation of biological brain function for information processing and can potentially solve the bottleneck of the von Neumann architecture.This computing is realized based on memristive hardware neural networks in which synaptic devices that mimic biological synapses of the brain are the primary units.Mimicking synaptic functions with these devices is critical in neuromorphic systems.In the last decade,electrical and optical signals have been incorporated into the synaptic devices and promoted the simulation of various synaptic functions.In this review,these devices are discussed by categorizing them into electrically stimulated,optically stimulated,and photoelectric synergetic synaptic devices based on stimulation of electrical and optical signals.The working mechanisms of the devices are analyzed in detail.This is followed by a discussion of the progress in mimicking synaptic functions.In addition,existing application scenarios of various synaptic devices are outlined.Furthermore,the performances and future development of the synaptic devices that could be significant for building efficient neuromorphic systems are prospected.
基金financial support from National Science Foundation of China(51602040,51872039)Science and Technology Program of Sichuan(M112018JY0025)Scientific Research Foundation for New Teachers of UESTC(A03013023601007)。
文摘Emulating synaptic plasticity in an artificial neural network is crucial to mimic the basic functions of the human brain.In this work,we report a new optoelectronic resistive random access memory(ORRAM)in a three-layer vertical heterostructure of graphene/Cd Se quantum dots(QDs)/graphene,which shows non-volatile multi-level optical memory under optical stimuli,giving rise to light-tunable synaptic behaviors.The optical non-volatile storage time is up to^450 s.The device realizes the function of multi-level optical storage through the interlayer changes between graphene and QDs.This work highlights the feasibility for applying two-dimensional(2D)materials in ORRAM and optoelectronic synaptic devices towards artificial vision.
基金supported by the National Science Foundation for Distinguished Young Scholars of China(T2125005)Tianjin Science Foundation for Distinguished Young Scholars(19JCJQJC61000)the Shenzhen Science and Technology Project(JCYJ20210324121002008).
文摘The ionic environment of body fluids influences nervous functions for maintaining homeostasis in organisms and ensures normal perceptual abilities and reflex activities.Neural reflex activities,such as limb movements,are closely associated with potassium ions(K+).In this study,we developed artificial synaptic devices based on ion concentration-adjustable gels for emulating various synaptic plasticities under different K+concentrations in body fluids.In addition to performing essential synaptic functions,potential applications in information processing and associative learning using short-and long-term plasticity realized using ion concentration-adjustable gels are presented.Artificial synaptic devices can be used for constructing an artificial neural pathway that controls artificial muscle reflex activities and can be used for image pattern recognition.All tests show a strong relationship with ion homeostasis.These devices could be applied to neuromorphic robots and human-machine interfaces.
基金supported by the National Natural Science Foun-dation of China(Nos.11774001,52202156,52103297)the Anhui Project(No.Z010118169)+2 种基金the Scientific research project of colleges and universities in Anhui Province(No.2022AH050113)the Uni-versity Synergy Innovation Program of Anhui Province(No.GXXT-2022-012)the Postdoctoral daily public start-up funds of An-hui University(No.S202418001/069).
文摘The development of high-performance neuromorphic phototransistors is of paramount importance for image perception and depth memory learning.Here,based on metal-oxide heterojunction architecture,artificial synaptic phototransistors with synaptic plasticity have been achieved,demonstrating an artificial synapse that integrates central and optic nerve functions.Thanks to the sensitive light-detection properties,the optical power consumption of such photonic artificial synapses can be as low as 22 picojoules,which is extremely competitive compared with other pure metal oxide photoelectric synapses ever reported.What is more,owing to its good short-term(STP)and tunable amplitude-frequency characteristics,the as-constructed device can function as a biomimetic high-pass filter for picture edge detection.Dual-mode synaptic modulation has been performed,combining photonic pulse with gate voltage stimulus.After photoelectric-synergistic modulation,the high synaptic weights enable the device to simulate complex neural learning rules for neuromorphic applications,including gesture recognition,image perception in the visual system,and classically conditioned reflexes.These results suggest that the current oxide-based heterojunction architecture displays potential application in future multifunction neuromorphic devices and systems.
文摘A unique optoelectronic synaptic device has been developed,leveraging the negative photoconductance property of a single-crystal material system called Cs2CoCl4.This device exhibits a simultaneous volatile resistive switching response and sensitivity to optical stimuli,positioning Cs2CoCl4 as a promising candidate for optically enhanced neuromorphicapplications.
基金supported by the National Natural Science Foundation of China (61874029)。
文摘Synaptic devices that merge memory and processing functions into one unit have broad application potentials in neuromorphic computing, soft robots, and humanmachine interfaces. However, most previously reported synaptic devices exhibit fixed performance once been fabricated,which limits their application in diverse scenarios. Here, we report floating-gate photosensitive synaptic transistors with charge-trapping perovskite quantum dots(PQDs) and atomic layer deposited(ALD) Al_(2)O_(3) tunneling layers, which exhibit typical synaptic behaviors including excitatory postsynaptic current(EPSC), pair-pulse facilitation and dynamic filtering characteristics under both electrical or optical signal stimulation. Further, the combination of the high-quality Al2O3 tuning layer and highly photosensitive PQDs charge-trapping layer provides the devices with extensively tunable synaptic performance under optical and electrical co-modulation. Applying light during electrical modulation can significantly improve both the synaptic weight changes and the nonlinearity of weight updates, while the memory effect under light modulation can be obviously adjusted by the gate voltage.The pattern learning and forgetting processes for "0" and "1"with different synaptic weights and memory times are further demonstrated in the device array. Overall, this work provides synaptic devices with tunable functions for building complex and robust artificial neural networks.
基金mainly supported by the National Key Research and Development Program of China(2017YFA0205700)the National Natural Science Foundation of China(NSFC,61774133 and 6147409)Partial support from the NSFC for Innovative Research Groups(61721005)
文摘The quantum-dot light-emitting diodes(QLEDs)that emit near-infrared(NIR)light may be important optoelectronic synaptic devices for the realization of artificial neural networks with complete optoelectronic integration.To improve the performance of NIR QLEDs,we take advantage of their low-energy light emission to explore the use of poly(3-hexylthiophene)(P3 HT)as the hole transport layer(HTL).P3 HT has one of the highest hole mobilities among organic semiconductors and essentially does not absorb NIR light.The usage of P3 HT as the HTL indeed significantly mitigates the imbalance of carrier injection in NIR QLEDs.With the additional incorporation of an interlayer of poly[9,9-bis(3’-(N,N-dimethylamino)propyl)-2,7-flourene]-alt-2,7-(9,9-dioctylfluorene)],P3 HT obviously improves the performance of NIR QLEDs.As electroluminescent synaptic devices,these NIR QLEDs exhibit important synaptic functionalities such as short-and long-term plasticity,and may be employed for image recognition.
基金the National Natural Science Foundation of China(No.62074111)the Science and Technology Foundation of Shanghai(Nos.19JC1412402 and 20JC1415600)+3 种基金Shanghai Municipal Science and Technology Major Project(No.2021SHZDZX0100)Shanghai Municipal Commission of Science and Technology Project(No.19511132101)the Chinese Academy of Sciences(Hundred Talents Plan),the China Postdoctoral Science Foundation funded project(No.2019M660807)the support of the Fundamental Research Funds for the Central Universities.
文摘Artificial synaptic devices hold great potential in building neuromorphic computers.Due to the unique morphological features,twodimensional organic semiconductors at the monolayer limit show interesting properties when acting as the active layers for organic field-effect transistors.Here,organic synaptic transistors are prepared with 1,4-bis((5’-hexyl-2,2’-bithiophen-5-yl)ethyl)benzene(HTEB)monolayer molecular crystals.Functions similar to biological synapses,including excitatory postsynaptic current(EPSC),pair-pulse facilitation,and short/long-term memory,have been realized.The synaptic device achieves the minimum power consumption of 4.29 fJ at low drain voltage of−0.01 V.Moreover,the HTEB synaptic device exhibits excellent long-term memory with 109 s EPSC estimated retention time.Brain-like functions such as dynamic learning-forgetting process and visual noise reduction are demonstrated by nine devices.The unique morphological features of the monolayer molecular semiconductors help to reveal the device working mechanism,and the synaptic behaviors of the devices can be attributed to oxygen induced energy level.This work shows the potential of artificial neuroelectronic devices based on organic monolayer molecular crystals.
