Van der Waals(vdW)heterobilayers formed by two-dimensional(2D)transition metal dichalcogenides(TMDCs)created a promising platform for various electronic and optical properties,ab initio band results indicate that the ...Van der Waals(vdW)heterobilayers formed by two-dimensional(2D)transition metal dichalcogenides(TMDCs)created a promising platform for various electronic and optical properties,ab initio band results indicate that the band offset of type-Ⅱband alignment in TMDCs vdW heterobilayer could be tuned by introducing Janus WSSe monolayer,instead of an external electric field.On the basis of symmetry analysis,the allowed interlayer hopping channels of TMDCs vdW heterobilayer were determined,and a four-level k·p model was developed to obtain the interlayer hopping.Results indicate that the interlayer coupling strength could be tuned by interlayer electric polarization featured by various band offsets.Moreover,the difference in the formation mechanism of interlayer valley excitons in different TMDCs vdW heterobilayers with various interlayer hopping strength was also clarified.展开更多
Van der Waals heterostructures have recently emerged,in which two distinct transitional metal dichalcogenide(TMD)monolayers are stacked vertically to generate interlayer excitons(IXs),offing new opportunites for the d...Van der Waals heterostructures have recently emerged,in which two distinct transitional metal dichalcogenide(TMD)monolayers are stacked vertically to generate interlayer excitons(IXs),offing new opportunites for the design of optoelectronic devices.However,the bilayer heterostructure with type-II band alignment can only produce low quantum yield.Here,we present the observation of interlayer neutral excitons and trions in the MoSe_(2)/MoS_(2)/MoSe_(2)trilayer heterostructure(Tri-HS).In comparison to the 8 K bilayer heterostructure,the addition of a MoSe_(2)layer to the Tri-HS can significantly increase the quantum yield of IXs.It is believed the two symmetrical type-II band alignments formed in the Tri-HS could effectively promote the IX radiation recombination.By analyzing the photoluminescence(PL)spectrum of the IXs at cryogenic temperature and the power dependence,the existence of the interlayer trions was confirmed.Our results provide a promising platform for the development of more efficient optoelectronic devices and the investigation of new physical properties of TMDs.展开更多
Superconductivity is typically considered incompatible with ferromagnetism.Great efforts have been devoted to achieving the simultaneous coexistence of these two competing phenomena in a single system.However,previous...Superconductivity is typically considered incompatible with ferromagnetism.Great efforts have been devoted to achieving the simultaneous coexistence of these two competing phenomena in a single system.However,previous attempts to integrate ferromagnetism and superconductivity have primarily focused on creating artificial heterostructures,separating them into distinct vertical layers.Simple and efficient strategies for realizing the in-plane coexistence of ferromagnetism and superconductivity remain a great challenge.Here,we report an interlayer-confined decoration strategy to embed ferromagnetic order into superconducting TaS_(2)lattice by decorating isolated Fe atoms,while preserving the intralayer lattice of TaS_(2).In Fe-decorated TaS_(2),Fe atoms in the single-atom form exhibit two distinct configurations,namely,substituting Ta atoms and being anchored at the interstitial sites.Both configurations result in the generation of local magnetic moments via the hybridization of Fe-3d,Ta-5d,and S-2p electronic states.Notably,this strategy can be extended to other metal atoms such as magnetic Co,Ni and Mn,as well as non-magnetic Pt and Cu,serving as a general approach for chemically manipulating the electronic properties of two-dimensional(2D)materials and offering new possibilities in artificial design and synthesis of novel quantum materials.展开更多
基金supported by the National Natural Science Foundation of China(No.51872170)Young Scholars Program of Shandong University(YSPSDU)+2 种基金Shandong Provincial Key Research and Development Program(Major Scientific and Technological Innovation Project)(No.2019JZZY010302)the Natural Science Foundation of Shandong Province(No.ZR2019MEM013)Taishan Scholar Program of Shandong Province.
文摘Van der Waals(vdW)heterobilayers formed by two-dimensional(2D)transition metal dichalcogenides(TMDCs)created a promising platform for various electronic and optical properties,ab initio band results indicate that the band offset of type-Ⅱband alignment in TMDCs vdW heterobilayer could be tuned by introducing Janus WSSe monolayer,instead of an external electric field.On the basis of symmetry analysis,the allowed interlayer hopping channels of TMDCs vdW heterobilayer were determined,and a four-level k·p model was developed to obtain the interlayer hopping.Results indicate that the interlayer coupling strength could be tuned by interlayer electric polarization featured by various band offsets.Moreover,the difference in the formation mechanism of interlayer valley excitons in different TMDCs vdW heterobilayers with various interlayer hopping strength was also clarified.
基金support from the National Natural Science Foundation of China(Nos.61775241,62090035,and U19A2090)the Science and Technology Innovation Basic Research Project of Shenzhen(No.JCYJ20180307151237242)+5 种基金Hunan Province Key Research and Development Project(No.2019GK2233)Hunan Provincial Science Fund for Distinguished Young Scholars(No,2020JJ2059)the Key Program of Science and Technology Department of Hunan Province(Nos.2019XK2001 and 2020XK2001)the Youth Innovation Team(No,2019012)of Central South UniversityThe authors are also thankful for the support of the High Performance Complex Manufacturing Key State Lab Project,Central South University(No.ZZYJKT2020-12)Z.W.L.thanks the support from the Australian Research Council(ARC Discovery Project,No.DP180102976).
文摘Van der Waals heterostructures have recently emerged,in which two distinct transitional metal dichalcogenide(TMD)monolayers are stacked vertically to generate interlayer excitons(IXs),offing new opportunites for the design of optoelectronic devices.However,the bilayer heterostructure with type-II band alignment can only produce low quantum yield.Here,we present the observation of interlayer neutral excitons and trions in the MoSe_(2)/MoS_(2)/MoSe_(2)trilayer heterostructure(Tri-HS).In comparison to the 8 K bilayer heterostructure,the addition of a MoSe_(2)layer to the Tri-HS can significantly increase the quantum yield of IXs.It is believed the two symmetrical type-II band alignments formed in the Tri-HS could effectively promote the IX radiation recombination.By analyzing the photoluminescence(PL)spectrum of the IXs at cryogenic temperature and the power dependence,the existence of the interlayer trions was confirmed.Our results provide a promising platform for the development of more efficient optoelectronic devices and the investigation of new physical properties of TMDs.
基金supported by the National Natural Science Foundation of China(21925110,22321001,223B1014)the National Key Research and Development Program of China(2022YFA1203600)+8 种基金the Chinese Academy of Sciences Project for Young Scientists in Basic Research(YSBR-070)University of Science and Technology of China(USTC)Research Funds of the Double First-Class Initiative(YD2060002004)the Anhui Provincial Natural Science Foundation(2408085J012)the Key R&D Program of Shandong Province(2021CXGC010302)the Youth Innovation Promotion Association,Chinese Academy of Sciences(2018500)the support from the beamline 1W1B at the Beijing Synchrotron Radiation Facility(BSRF,Beijing,China)the BL14W1 beamline at the Shanghai Synchrotron Radiation Facility(SSRF,Shanghai,China)the beamline BL12B-a of the National Synchrotron Radiation Laboratory(NSRL,Hefei,China)the support from the Super Computer Centre of University of Science and Technology of China。
文摘Superconductivity is typically considered incompatible with ferromagnetism.Great efforts have been devoted to achieving the simultaneous coexistence of these two competing phenomena in a single system.However,previous attempts to integrate ferromagnetism and superconductivity have primarily focused on creating artificial heterostructures,separating them into distinct vertical layers.Simple and efficient strategies for realizing the in-plane coexistence of ferromagnetism and superconductivity remain a great challenge.Here,we report an interlayer-confined decoration strategy to embed ferromagnetic order into superconducting TaS_(2)lattice by decorating isolated Fe atoms,while preserving the intralayer lattice of TaS_(2).In Fe-decorated TaS_(2),Fe atoms in the single-atom form exhibit two distinct configurations,namely,substituting Ta atoms and being anchored at the interstitial sites.Both configurations result in the generation of local magnetic moments via the hybridization of Fe-3d,Ta-5d,and S-2p electronic states.Notably,this strategy can be extended to other metal atoms such as magnetic Co,Ni and Mn,as well as non-magnetic Pt and Cu,serving as a general approach for chemically manipulating the electronic properties of two-dimensional(2D)materials and offering new possibilities in artificial design and synthesis of novel quantum materials.
