The van der Waals(vd W)material Cr SBr exhibits a distinctive hetero-bonded structure,characterized by fence-like and rectangular configurations viewed from different crystallographic orientations.Mechanical deformati...The van der Waals(vd W)material Cr SBr exhibits a distinctive hetero-bonded structure,characterized by fence-like and rectangular configurations viewed from different crystallographic orientations.Mechanical deformation of this unique structure can induce significant anisotropic electronic and optical properties.In this study,we systematically investigate the non-synchronous strain response of Cr SBr through theoretical and experimental approaches.Our results reveal that the electronic band structure of Cr SBr is predominantly governed by the intralayer Cr-S bonds along the b-axis,whereas the characteristic Raman peak A_(g)^(3)arises from interlayer Cr-S bond vibrations in each quasi-monolayer.Notably,the different strain responses of these two types of bonds,stemming from the hetero-bonded architecture,lead to distinct behaviors in photoluminescence(PL)and Raman spectra under uniaxial strain.Specifically,the electronic band structure demonstrates heightened sensitivity to tensile strain along the b-axis,while the A_(g)^(3)Raman mode exhibits greater sensitivity to strain along the a-axis.These insights advance the understanding of strain-induced anisotropies in Cr SBr and provide valuable guidance for the design of vd W-based optoelectronic devices.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
Photodetectors equipped with multi-parameter control hold the potential to deliver exceptional performance in a wide range of scenarios,paving the way for developing novel spin-opto-electronic devices.Nevertheless,the...Photodetectors equipped with multi-parameter control hold the potential to deliver exceptional performance in a wide range of scenarios,paving the way for developing novel spin-opto-electronic devices.Nevertheless,the integration of such capabilities within a single device is challenging due to the necessity of harmonizing multiple materials with varying degrees of freedom.In this study,we introduce the van der Waals magnet CrSBr,featuring inherent anisotropy and distinctive spin-electronic coupling,to this realm.The linear dichroic ratio of the photocurrent in CrSBr tunneling device can reach~60 at 1.65 K,and the photoresponse experiences a significant boost with increasing magnetic field.Additionally,the unique spin-charge coupling engenders a photon energy-dependent photocurrent that is modulated by an external field and is validated by first-principle calculations.Our findings elucidate the effective multi-parameter control of photodetection based on vdWs magnet CrsBr,highlighting its potential applications in cutting-edge optoelectronic devices and as a highly sensitive probe medium.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.52471248,12174364,12204009,12104003)the Natural Science Foundation of Anhui Province,China(Grant No.2308085Y04)+1 种基金the National Key Research and Development Program of China(Grant No.2023YFA1406400)the Fundamental Research Funds for the Central Universities(Grant No.wk2310000104)。
文摘The van der Waals(vd W)material Cr SBr exhibits a distinctive hetero-bonded structure,characterized by fence-like and rectangular configurations viewed from different crystallographic orientations.Mechanical deformation of this unique structure can induce significant anisotropic electronic and optical properties.In this study,we systematically investigate the non-synchronous strain response of Cr SBr through theoretical and experimental approaches.Our results reveal that the electronic band structure of Cr SBr is predominantly governed by the intralayer Cr-S bonds along the b-axis,whereas the characteristic Raman peak A_(g)^(3)arises from interlayer Cr-S bond vibrations in each quasi-monolayer.Notably,the different strain responses of these two types of bonds,stemming from the hetero-bonded architecture,lead to distinct behaviors in photoluminescence(PL)and Raman spectra under uniaxial strain.Specifically,the electronic band structure demonstrates heightened sensitivity to tensile strain along the b-axis,while the A_(g)^(3)Raman mode exhibits greater sensitivity to strain along the a-axis.These insights advance the understanding of strain-induced anisotropies in Cr SBr and provide valuable guidance for the design of vd W-based optoelectronic devices.
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 Key R&D Program of China(no.2022YFA1203902)the National Natural Science Foundation of China(no.12425402 and no.12250007)+1 种基金Bejing Natural Science Foundation(no.JQ21018)the China Postdoctoral Science Foundation(2023TQ0003 and 2023M740122).
文摘Photodetectors equipped with multi-parameter control hold the potential to deliver exceptional performance in a wide range of scenarios,paving the way for developing novel spin-opto-electronic devices.Nevertheless,the integration of such capabilities within a single device is challenging due to the necessity of harmonizing multiple materials with varying degrees of freedom.In this study,we introduce the van der Waals magnet CrSBr,featuring inherent anisotropy and distinctive spin-electronic coupling,to this realm.The linear dichroic ratio of the photocurrent in CrSBr tunneling device can reach~60 at 1.65 K,and the photoresponse experiences a significant boost with increasing magnetic field.Additionally,the unique spin-charge coupling engenders a photon energy-dependent photocurrent that is modulated by an external field and is validated by first-principle calculations.Our findings elucidate the effective multi-parameter control of photodetection based on vdWs magnet CrsBr,highlighting its potential applications in cutting-edge optoelectronic devices and as a highly sensitive probe medium.
