W-doped In_(2)O_(3) nanofiber optoelectronic neuromorphic transistors with synergistic synaptic plasticity

Neuromorphic devices that mimic the information processing function of biological synapses and neurons have attracted considerable attention due to their potential applications in brain-like perception and computing. In this paper,neuromorphic transistors with W-doped In_(2)O_(3)nanofibers as the channel layers are fabricated and optoelectronic synergistic synaptic plasticity is also investigated. Such nanofiber transistors can be used to emulate some biological synaptic functions, including excitatory postsynaptic current(EPSC), long-term potentiation(LTP), and depression(LTD). Moreover, the synaptic plasticity of the nanofiber transistor can be synergistically modulated by light pulse and electrical pulse.At last, pulsed light learning and pulsed electrical forgetting behaviors were emulated in 5×5 nanofiber device array.Our results provide new insights into the development of nanofiber optoelectronic neuromorphic devices with synergistic synaptic plasticity.

CMOS-compatible neuromorphic devices for neuromorphic perception and computing: a review

Neuromorphic computing is a brain-inspired computing paradigm that aims to construct efficient,low-power,and adaptive computing systems by emulating the information processing mechanisms of biological neural systems.At the core of neuromorphic computing are neuromorphic devices that mimic the functions and dynamics of neurons and synapses,enabling the hardware implementation of artificial neural networks.Various types of neuromorphic devices have been proposed based on different physical mechanisms such as resistive switching devices and electric-double-layer transistors.These devices have demonstrated a range of neuromorphic functions such as multistate storage,spike-timing-dependent plasticity,dynamic filtering,etc.To achieve high performance neuromorphic computing systems,it is essential to fabricate neuromorphic devices compatible with the complementary metal oxide semiconductor(CMOS)manufacturing process.This improves the device’s reliability and stability and is favorable for achieving neuromorphic chips with higher integration density and low power consumption.This review summarizes CMOS-compatible neuromorphic devices and discusses their emulation of synaptic and neuronal functions as well as their applications in neuromorphic perception and computing.We highlight challenges and opportunities for further development of CMOS-compatible neuromorphic devices and systems.

关于后摩尔时代我国集成电路制造领域的一些思考

1.Background,As one of the fundamental and core industries of modern information technology,the integrated circuit(IC)is a basic and leading industry that is closely related to overall global economic and social development.The global semiconductor industry is poised for a decade of growth and is projected to become a trillion-dollar industry by 2030(Fig.1[1]).Technological level and industrial scale are important indicators for evaluating the degree of modernization and comprehensive national strength of a country or region.Hailed as the“industrial food”for a country,IC is the foundation for cultivating and developing strategic emerging industries and promoting the deep integration of informatization and industrialization.Demand for both cutting-edge chips and high-reliability chips continues to be strong in applications deployed throughout the field,from Industry 4.0 to automotive electronics,artificial intelligence,and so forth.As the focus of current international competition,IC also plays a broad and key role in promoting national economic development and social progress,improving people’s living standards,and ensuring national security.The current competition is not related to a certain technology node or single specific technology.Rather,this core competitiveness is the overall strength of the IC industry chain and relies on the ability to track the dynamic targets of industrial development,which fully depends on the support of the global high-end basic industry.

The past and future of multi-gate field-effect transistors:Process challenges and reliability issues

This work reviews the state-of-the art multi-gate field-effect transistor(MuGFET)process technologies and compares the device performance and reliability characteristics of the MuGFETs with the planar Si CMOS devices.Owing to the 3D wrapped gate structure,MuGFETs can suppress the SCEs and improve the ON-current performance due to the volume inversion of the channel region.As the Si CMOS technology pioneers to sub-10 nm nodes,the process challenges in terms of lithography capability,process integration controversies,performance variability etc.were also discussed in this work.Due to the severe self-heating effect in the MuGFETs,the ballistic transport and reliability characteristics were investigated.Future alternatives for the current Si MuGFET technology were discussed at the end of the paper.More work needs to be done to realize novel high mobility channel MuGFETs with better performance and reliability.

Mobility enhancement techniques for Ge and GeSn MOSFETs

The performance enhancement of conventional Si MOSFETs through device scaling is becoming increasingly difficult.The application of high mobility channel materials is one of the most promising solutions to overcome the bottleneck.The Ge and GeSn channels attract a lot of interest as the alternative channel materials,not only because of the high carrier mobility but also the superior compatibility with typical Si CMOS technology.In this paper,the recent progress of high mobility Ge and GeSn MOSFETs has been investigated,providing feasible approaches to improve the performance of Ge and GeSn devices for future CMOS technologies.

Recent advances in bioinspired vision systems with curved imaging structures

Limited by the planar imaging structure,the commercial camera needs to introduce additional optical elements to compensate for the curved focal plane to match the planar image sensor.This results in a complex and bulky structure.In contrast,biological eyes possess a simple and compact structure due to their curved imaging structure that can directly match with the curved focal plane.Inspired by the structures and functions of biological eyes,curved vision systems not only improve the image quality,but also offer a variety of advanced functions.Here,we review the recent advances in bioinspired vision systems with curved imaging structures.Specifically,we focus on their applications in implementing different functions of biological eyes,as well as the emerging curved neuromorphic imaging systems that incorporate bioinspired optical and neuromorphic processing technologies.In addition,the challenges and opportunities of bioinspired curved imaging systems are also discussed.

Gate-tunable high-performance broadband phototransistor array of two-dimensional PtSe_(2) on SOI

Two-dimensional(2D)layered materials have attracted extensive research interest in the field of high-performance photodetection due to their high carrier mobility,tunable bandgap,stability,other excellent properties.Herein,we propose a gate-tunable,high-performance,self-driving,wide detection range phototransistor based on a 2D PtSe_(2)on silicon-oninsulator(SOI).Benefiting from the strong built-in electric field of the PtSe_(2)/Si heterostructure,the phototransistor has a fast response time(rise/fall time)of 36.7/32.6μs.The PtSe_(2)/Si phototransistor exhibits excellent photodetection performance over a broad spectral range from ultraviolet to near-infrared,including a responsivity of 1.07 A/W and a specific detectivity of 6.60×10^(9)Jones under 808 nm illumination at zero gate voltage.The responsivity and specific detectivity of PtSe_(2)/Si phototransistor at 5 V gate voltage are increased to 13.85 A/W and 1.90×10^(10) Jones under 808 nm illumination.Furthermore,the fabricated PtSe_(2)/Si phototransistor array shows excellent uniformity,reproducibility,long-term stability in terms of photoresponse performance with negligible variation between pixel cells.The architecture of present PtSe_(2)/Si on SOI platform paves a new way of a general strategy to realize high-performance photodetectors by combining the advantages of both 2D materials and conventional semiconductors which is compatible with current Si-complementary metal oxide semiconductor(CMOS)process.

与硅基CMOS兼容且具有超高响应率和比探测率的二维二硒化铂自驱动光电探测器

因二维材料的独特性质及其可调谐的光谱响应,基于二维材料的光电探测器受到广泛关注.然而,它们的性能还不够突出,其制造工艺与硅基互补金属氧化物半导体技术工艺流程的兼容性还需要评估.在本文中,我们报道了一种基于二硒化铂/超薄二氧化硅/硅异质结构的高性能、空气稳定、自驱动、室温宽带光电探测器.该光电探测器表现出超高的响应度(8.06 AW-1)和比探测率(4.78×10^(13)cm Hz^(1/2)W^(-1))、极低的暗电流(0.12 pA)以及优秀的开关比(1.29×10^(9)).在375,532,1342和1550 nm波长处所测的光电流响应度分别为2.12,5.56,18.12和0.65 m AW^(-1).此外,制造的9×9器件阵列不仅展示了该探测器非常好的均匀性和可重复性,而且还显示了其在紫外-可见-近红外照明成像应用领域的潜力.我们设计的二硒化铂/超薄二氧化硅/硅异质结光电探测器极大地抑制了暗电流,提高了二极管的理想因子并增加了界面势垒.因此,它为改善光电探测器性能的设计提供了一种新策略.

Plasmon resonance-enhanced graphene nanofilmbased dual-band infrared silicon photodetector

Graphene-based photodetectors have attracted much attention due to their unique properties,such as high-speed and wide-band detection capability.However,they suffer from very low external quantum efficiency in the infrared(IR)region and lack spectral selectivity.Here,we construct a plasmon-enhanced macro-assembled graphene nanofilm(nMAG)based dual-band infrared silicon photodetector.The Au plasmonic nanostructures improve the absorption of long-wavelength photons with energy levels below the Schottky barrier(between metal and Si)and enhance the interface transport of electrons.Combined with the strong photo-thermionic emission(PTI)effect of nMAG,the n MAG–Au–Si heterojunctions show strong dual-band detection capability with responsivities of52.9 mA/W at 1342 nm and 10.72 mA/W at 1850 nm,outperforming IR detectors without plasmonic nanostructures by 58–4562 times.The synergy between plasmon–exciton resonance enhancement and the PTI effect opens a new avenue for invisible light detection.

具有超薄Al_(2)O_(3)钝化层的高性能近红外PtSe_(2)/n-Ge异质结光电探测器

二维(2D)材料正被广泛用于宽带响应光电探测器(PD).然而,基于2D材料的宽带响应PD通常对红外波长的响应较差.在此,我们报告了垂直PtSe_(2)/超薄Al_(2)O_(3)/Ge PD在近红外照明下的优异光响应性能.我们直接硒化沉积在Al_(2)O_(3)/Ge上的Pt膜以形成PtSe_(2)层.超薄Al_(2)O_(3)钝化层起到表面改性的作用,有效地削弱了光生载流子的复合.在1550 nm的光照下,我们的PtSe_(2)/超薄Al_(2)O_(3)/Ge PD的工作面积为50μm×50μm,并在零偏压下获得了4.09 A W^(-1)、32.6/18.9μs的大响应度和快速上升/下降时间.在-5 V的外加电压下,PtSe_(2)/超薄Al_(2)O_(3)/Ge PD的响应度和响应速度分别高达38.18 A W^(-1)和9.6/7.7μs.我们发现器件的工作面积对光响应特性有很大的影响.此外,我们证明PtSe_(2)/超薄Al_(2)O_(3)/Ge PD阵列在室温下显示出了优异的紫外、可见光和红外成像能力.我们的研究表明,PtSe_(2)/超薄Al_(2)O_(3)/Ge异质结在设计具有优异近红外响应性能的新兴宽带光电子器件方面具有巨大的应用前景.

Core processing neuron-enabled circuit motifs for neuromorphic computing

Based on brain-inspired computing frameworks,neuromorphic systems implement large-scale neural networks in hardware.Although rapid advances have been made in the development of artificial neurons and synapses in recent years,further research is beyond these individual components and focuses on neuronal circuit motifs with specialized excitatory-inhibitory(E-I)connectivity patterns.In this study,we demonstrate a core processor that can be used to construct commonly used neuronal circuits.The neuron,featuring an ultracompact physical configuration,integrates a volatile threshold switch with a gate-modulated two-dimensional(2D)MoS_(2) field-effect channel to process complex E-I spatiotemporal spiking signals.Consequently,basic neuronal circuits are constructed for biorealistic neuromorphic computing.For practical applications,an algorithm-hardware co-design is implemented in a gatecontrolled spiking neural network with substantial performance improvement in human speech separation.

High performance IEICO-4F/WSe_(2)heterojunction photodetector based on photoluminescence quenching behavior

Heterostructure is the basic building block for functional optoelectronic devices.Heterostructures consisting of two-dimensional(2D)transition metal dichalcogenides(TMDs)and organic semiconductors are currently attracting great interest for highperformance optoelectronics.However,how to design heterostructure for highly efficient optoelectronic devices remains a big challenge.Here we design high-performance organic semiconductor/WSe_(2)heterostructure photodetectors by tailoring the charge transfer effect between 2,2ʹ-((2Z,2ʹZ)-(((4,4,9,9-tetrakis(4-hexylphenyl)-4,9-dihydros-indaceno[1,2-b:5,6-bʹ]dithiophene-2,7-diyl)bis(4-((2-ethylhexyl)oxy)thiophene-5,2-diyl))bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile(IEICO-4F)organic semiconductors with various thicknesses and monolayer WSe_(2).With the increase of IEICO-4F layer thickness,the photoluminescence(PL)characteristics of WSe_(2)could be completely quenched due to the charge transfer from the lowest unoccupied molecular orbital(LUMO)level of IEICO-4F to the conduction band minimum(CBM)of WSe_(2).Benefiting from the exquisite charge transfer behavior,the IEICO-4F/WSe_(2)heterojunction photodetector with optimized 6.0-nm thick IEICO-4F shows high performance including the responsivity of 8.32 A/W and specific detectivity of 4.65×10^(11)Jones at incident light of 808 nm.This work demonstrates a simple approach based on PL characteristics to design high-performance IEICO-4F/WSe_(2)heterojunction,thus paving the way for the development of excellent optoelectronic devices based on organic/TMD heterostructures.

Strong Interlayer Interaction for Engineering Two-Dimensional Materials

CONSPECTUS:Two-dimensional(2D)layered materials have atomically thin thickness and outstanding physical properties,attracting intensive research in past years.To realize the applications in(opto)electronic devices,the strategies to engineer the properties of 2D materials have been widely explored,including defect engineering,in-plane strain engineering,surface modification,etc.Besides the in-plane bonding,the out-of-plane interlayer interaction is another unique degree of freedom to engineer the properties of 2D materials.Different from the well-accepted weak van der Waals interactions,some recently discovered 2D material systems display strong interlayer interaction with“covalent-like quasi-bonding”.