Emulation of advanced synaptic functions of the human brain with electronic devices contributes an important step toward constructing high‐efficiency neuromorphic systems.Ferroelectric materials are promising candida...Emulation of advanced synaptic functions of the human brain with electronic devices contributes an important step toward constructing high‐efficiency neuromorphic systems.Ferroelectric materials are promising candidates as synaptic weight elements in neural network hardware due to their controllable polarization states.However,the increased depolarization field at the na-noscale and the complex fabrication process of the traditional ferroelectric materials hamper the development of high‐density,low‐power,and highly sensitive synaptic devices.Here,we report the implementation of two‐dimensional(2D)ferroelectricα‐In_(2)Se_(3)as an active channel material to emulate typical synaptic functions.Theα‐In_(2)Se_(3)‐based synaptic device fea-tures multimode operations,enabled by the coupled ferroelectric polarization under various voltage pulses applied at both drain and gate terminals.Moreover,the energy consumption can be reduced to~1 pJ by using high‐κdielectric(Al2O3).The successful control of ferroelectric polarizations inα‐In_(2)Se_(3)and its application in artificial synapses are expected to inspire the implementation of 2D ferroelectric materials for future neuromorphic systems.展开更多
Detection of solar-blind ultraviolet(SB-UV)light is important in applications like confidential communication,flame detection,and missile warning system.However,the existing SB-UV photodetectors still show low sensiti...Detection of solar-blind ultraviolet(SB-UV)light is important in applications like confidential communication,flame detection,and missile warning system.However,the existing SB-UV photodetectors still show low sensitivities.In this work,we demonstrate the extraordinary SB-UV detection performance of α-In_(2)Se_(3 )phototransistors.Benefiting from the coupled semiconductor and ferroelectricity property,the phototransistor has an ultraweak detectable power of 17.85 fW,an ultrahigh gain of 1.2×10^(6),a responsivity of 2.6×10^(5) A/W,a detectivity of 1.3×10^(16) Jones and an ultralow noise-equivalent-power of 4.2×10^(–20 )W/Hz1/2 for 275 nm light.Its performance exceeds most other UV detectors,even including commercial photomultiplier tubes and avalanche photodiodes.It can be also implemented as an optoelectronic synapse for neuromorphic computing.A 784×300×10 artificial neural network(ANN)based on this optoelectronic synapse is constructed and demonstrated with a high recognition accuracy and good noise-tolerance for the Fashion-MNIST dataset.These extraordinary features endow this phototransistor with the potential for constructing advanced SB-UV detectors and intelligent hardware.展开更多
Memtransistors combine memristors and field-effect transistors, which can introduce multi-port control and have significant applications for enriching storage methods. In this paper, multilayer α-In2Se3and MoS2were t...Memtransistors combine memristors and field-effect transistors, which can introduce multi-port control and have significant applications for enriching storage methods. In this paper, multilayer α-In2Se3and MoS2were transferred to the substrate by the mechanical exfoliation method, then a heterojunction MoS_(2)/α-In_(2)Se_(3) memtransistor was prepared. Neural synaptic simulations were performed using electrical and optical pulses as input signals. Through measurements, such as excitatory/inhibitory post-synaptic current(EPSC/IPSC), long-term potentiation/depression(LTP/LTD), and paired-pulse facilitation/depression(PPF/PPD), it can be found that the fabricated device could simulate various functions of neural synapses well, and could work as an electronic synapse in artificial neural networks, proposing a possible solution for neuromorphic storage and computation.展开更多
Semiconducting piezoelectricα-In_(2)Se_(3) and 3R MoS_(2) have attracted tremendous attention due to their unique electronic properties.Artificial van der Waals(vdWs)hetero-structures constructed withα-In_(2)Se_(3)a...Semiconducting piezoelectricα-In_(2)Se_(3) and 3R MoS_(2) have attracted tremendous attention due to their unique electronic properties.Artificial van der Waals(vdWs)hetero-structures constructed withα-In_(2)Se_(3)and 3R MoS_(2)flakes have shown promising applications in optoelectronics and photocatal-ysis.Here,we present the first flexibleα-In_(2)Se_(3)/3R MoS_(2)vdWs p-n heterojunction devices for photodetection from the visible to near infrared region.These heterojunction devices exhibit an ultrahigh photoresponsivity of 2.9×10^(3)A W^(−1) and a substantial specific detectivity of 6.2×10^(10) Jones under a compressive strain of−0.26%.The photocurrent can be increased by 64%under a tensile strain of+0.35%,due to the heterojunction energy band modulation by piezoelectric polarization charges at the hetero-junction interface.This work demonstrates a feasible approach to enhancement of α-In_(2)Se_(3)/3R MoS_(2) photoelectric response through an appropriate mechanical stimulus.展开更多
Controlling the polar order in ferroelectric materials may enrich the diversity of their property and functionality,offering new opportunities for the design of novel electronic and optoelectronic devices.In this pape...Controlling the polar order in ferroelectric materials may enrich the diversity of their property and functionality,offering new opportunities for the design of novel electronic and optoelectronic devices.In this paper,we report a planar multi-state memory device built upon a twodimensional(2D)van der Waals layered ferroelectric material,2Hα-In_(2)Se_(3).Three(high,median and low)resistance states are demonstrated to be interconvertible in this device with a fast switching speed,excellent endurance and retention performances via the modulation of the polar order of the ferroelectricα-In_(2)Se_(3) layers under an in-plane electric field.Remarkably,reversible switching between the median-resistance state and the low-resistance state can be achieved by an ultralow electric field of 1-2 orders of magnitude smaller than the reported values in other 2D ferroelectric materialbased memory devices.Furthermore,the three different polar order states are discovered to exhibit distinctive photoresponses.These results demonstrate great potentials ofα-In_(2)Se_(3)in nonvolatile high-density memory and advanced optoelectronic device applications.展开更多
基金Ministry of Education—Singapore,Grant/Award Number:MOE‐2019‐T2‐1‐002National Natural Science Foundation of China,Grant/Award Numbers:21872100,U2032147Agency for Science,Technology and Research,Grant/Award Numbers:A1938c0035,A20G9b0135。
文摘Emulation of advanced synaptic functions of the human brain with electronic devices contributes an important step toward constructing high‐efficiency neuromorphic systems.Ferroelectric materials are promising candidates as synaptic weight elements in neural network hardware due to their controllable polarization states.However,the increased depolarization field at the na-noscale and the complex fabrication process of the traditional ferroelectric materials hamper the development of high‐density,low‐power,and highly sensitive synaptic devices.Here,we report the implementation of two‐dimensional(2D)ferroelectricα‐In_(2)Se_(3)as an active channel material to emulate typical synaptic functions.Theα‐In_(2)Se_(3)‐based synaptic device fea-tures multimode operations,enabled by the coupled ferroelectric polarization under various voltage pulses applied at both drain and gate terminals.Moreover,the energy consumption can be reduced to~1 pJ by using high‐κdielectric(Al2O3).The successful control of ferroelectric polarizations inα‐In_(2)Se_(3)and its application in artificial synapses are expected to inspire the implementation of 2D ferroelectric materials for future neuromorphic systems.
基金supported by the National Key R&D Program of China(Grant Nos.2021YFA1201500 and 2018YFA0703700)the National Natural Science Foundation of China(Nos.91964203,61974036,62274046,22179029,and 12204122)+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Nos.XDB44000000)the Fundamental Research Funds for the Central Universities(No.2042021kf0067)CAS Key Laboratory of Nanosystem and Hierarchical Fabrication.The authors also gratefully acknowledge the support of Youth Innovation Promotion Association CAS.
文摘Detection of solar-blind ultraviolet(SB-UV)light is important in applications like confidential communication,flame detection,and missile warning system.However,the existing SB-UV photodetectors still show low sensitivities.In this work,we demonstrate the extraordinary SB-UV detection performance of α-In_(2)Se_(3 )phototransistors.Benefiting from the coupled semiconductor and ferroelectricity property,the phototransistor has an ultraweak detectable power of 17.85 fW,an ultrahigh gain of 1.2×10^(6),a responsivity of 2.6×10^(5) A/W,a detectivity of 1.3×10^(16) Jones and an ultralow noise-equivalent-power of 4.2×10^(–20 )W/Hz1/2 for 275 nm light.Its performance exceeds most other UV detectors,even including commercial photomultiplier tubes and avalanche photodiodes.It can be also implemented as an optoelectronic synapse for neuromorphic computing.A 784×300×10 artificial neural network(ANN)based on this optoelectronic synapse is constructed and demonstrated with a high recognition accuracy and good noise-tolerance for the Fashion-MNIST dataset.These extraordinary features endow this phototransistor with the potential for constructing advanced SB-UV detectors and intelligent hardware.
基金Project supported by the National Natural Science Foundation of China (Grant No. 51702245)。
文摘Memtransistors combine memristors and field-effect transistors, which can introduce multi-port control and have significant applications for enriching storage methods. In this paper, multilayer α-In2Se3and MoS2were transferred to the substrate by the mechanical exfoliation method, then a heterojunction MoS_(2)/α-In_(2)Se_(3) memtransistor was prepared. Neural synaptic simulations were performed using electrical and optical pulses as input signals. Through measurements, such as excitatory/inhibitory post-synaptic current(EPSC/IPSC), long-term potentiation/depression(LTP/LTD), and paired-pulse facilitation/depression(PPF/PPD), it can be found that the fabricated device could simulate various functions of neural synapses well, and could work as an electronic synapse in artificial neural networks, proposing a possible solution for neuromorphic storage and computation.
基金MOE AcRF Tier2(2018-T2-2-005),MOE AcRF Tier1(2018-T1-005-001)A^(*)STAR AME IRG Grant SERC A1983c0027,Singapore.
文摘Semiconducting piezoelectricα-In_(2)Se_(3) and 3R MoS_(2) have attracted tremendous attention due to their unique electronic properties.Artificial van der Waals(vdWs)hetero-structures constructed withα-In_(2)Se_(3)and 3R MoS_(2)flakes have shown promising applications in optoelectronics and photocatal-ysis.Here,we present the first flexibleα-In_(2)Se_(3)/3R MoS_(2)vdWs p-n heterojunction devices for photodetection from the visible to near infrared region.These heterojunction devices exhibit an ultrahigh photoresponsivity of 2.9×10^(3)A W^(−1) and a substantial specific detectivity of 6.2×10^(10) Jones under a compressive strain of−0.26%.The photocurrent can be increased by 64%under a tensile strain of+0.35%,due to the heterojunction energy band modulation by piezoelectric polarization charges at the hetero-junction interface.This work demonstrates a feasible approach to enhancement of α-In_(2)Se_(3)/3R MoS_(2) photoelectric response through an appropriate mechanical stimulus.
基金supported by the National Natural Science Foundation of China(12174237,61904099,52002232 and 51871137)the Graduate Science and Technology Innovation Project of Shanxi Normal University(01053013)。
文摘Controlling the polar order in ferroelectric materials may enrich the diversity of their property and functionality,offering new opportunities for the design of novel electronic and optoelectronic devices.In this paper,we report a planar multi-state memory device built upon a twodimensional(2D)van der Waals layered ferroelectric material,2Hα-In_(2)Se_(3).Three(high,median and low)resistance states are demonstrated to be interconvertible in this device with a fast switching speed,excellent endurance and retention performances via the modulation of the polar order of the ferroelectricα-In_(2)Se_(3) layers under an in-plane electric field.Remarkably,reversible switching between the median-resistance state and the low-resistance state can be achieved by an ultralow electric field of 1-2 orders of magnitude smaller than the reported values in other 2D ferroelectric materialbased memory devices.Furthermore,the three different polar order states are discovered to exhibit distinctive photoresponses.These results demonstrate great potentials ofα-In_(2)Se_(3)in nonvolatile high-density memory and advanced optoelectronic device applications.
