1
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Li Y, Arsenault EA, Yang B, Wang X, Park H, Guo Y, Taniguchi T, Watanabe K, Gamelin D, Hone JC, Dean CR, Maehrlein SF, Xu X, Zhu X. Coherent Modulation of Two-Dimensional Moiré States with On-Chip THz Waves. NANO LETTERS 2024; 24:12156-12162. [PMID: 39303288 DOI: 10.1021/acs.nanolett.4c03129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2024]
Abstract
van der Waals (vdW) structures host a broad range of physical phenomena. New opportunities arise if different functional layers are remotely modulated or coupled in a device structure. Here we demonstrate the in situ coherent modulation of moiré excitons and correlated Mott insulators in transition metal dichalcogenide (TMD) moirés with on-chip terahertz (THz) waves. Using common dual-gated device structures of a TMD moiré bilayer sandwiched between two few-layer graphene (fl-Gr) gates with hexagonal boron nitride (h-BN) spacers, we launch coherent phonon wavepackets at ∼0.4-1 THz from the fl-Gr gates by femtosecond laser excitation. The waves travel through the h-BN spacer, arrive at the TMD bilayer with precise timing, and coherently modulate the moiré excitons or Mott states. These results demonstrate that the fl-Gr gates, often used for electrical control, can serve as on-chip opto-elastic transducers to generate THz waves for coherent control and vibrational entanglement of functional layers in moiré devices.
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Affiliation(s)
- Yiliu Li
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Eric A Arsenault
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Birui Yang
- Department of Physics, Columbia University, New York, New York 10027, United States
| | - Xi Wang
- Department of Physics, Washington University, St. Louis, Missouri 63130, United States
- Institute of Materials Science & Engineering, Washington University, St. Louis, Missouri 63130, United States
| | - Heonjoon Park
- Department of Physics, University of Washington, Seattle, Washington 98195, United States
| | - Yinjie Guo
- Department of Physics, Columbia University, New York, New York 10027, United States
| | - Takashi Taniguchi
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Kenji Watanabe
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Daniel Gamelin
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - James C Hone
- Department of Mechanical Engineering, Columbia University, New York, New York 10027, United States
| | - Cory R Dean
- Department of Physics, Columbia University, New York, New York 10027, United States
| | - Sebastian F Maehrlein
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin 14195, Germany
| | - Xiaodong Xu
- Department of Physics, University of Washington, Seattle, Washington 98195, United States
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Xiaoyang Zhu
- Department of Chemistry, Columbia University, New York, New York 10027, United States
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2
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Qu J, Cuddy EF, Han X, Liu J, Li H, Zeng YJ, Moritz B, Devereaux TP, Kirchmann PS, Shen ZX, Sobota JA. Screening of Polar Electron-Phonon Interactions near the Surface of the Rashba Semiconductor BiTeCl. PHYSICAL REVIEW LETTERS 2024; 133:106401. [PMID: 39303246 DOI: 10.1103/physrevlett.133.106401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 06/19/2024] [Accepted: 07/29/2024] [Indexed: 09/22/2024]
Abstract
Understanding electron-phonon coupling in noncentrosymmetric materials is critical for controlling the internal fields which give rise to Rashba interactions. We apply time- and angle-resolved photoemission spectroscopy (trARPES) to study coherent phonons in the surface and bulk regions of the polar semiconductor BiTeCl. Aided by ab initio calculations, our measurements reveal the coupling of out-of-plane A_{1} modes and an in-plane E_{2} mode. By considering how these modes modulate the electric dipole moment in each unit cell, we show that the polar A_{1} modes are more effectively screened in the metallic surface region, while the nonpolar E_{2} mode couples in both regions. In addition to informing strategies to optically manipulate Rashba interactions, this Letter has broader implications for the behavior of electron-phonon coupling in systems characterized by inhomogeneous dielectric environments.
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Affiliation(s)
- J Qu
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
- Geballe Laboratory for Advanced Materials, Department of Physics and Applied Physics, Stanford University, Stanford, California 94305, USA
| | | | - X Han
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
- Geballe Laboratory for Advanced Materials, Department of Physics and Applied Physics, Stanford University, Stanford, California 94305, USA
| | | | | | | | | | - T P Devereaux
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
- Geballe Laboratory for Advanced Materials, Department of Physics and Applied Physics, Stanford University, Stanford, California 94305, USA
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
| | | | - Z-X Shen
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
- Geballe Laboratory for Advanced Materials, Department of Physics and Applied Physics, Stanford University, Stanford, California 94305, USA
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3
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Zhou J, Huang H, Zhao Z, Dou Z, Zhou L, Zhang T, Huang Z, Feng Y, Shi D, Liu N, Yang J, Nie JC, Wang Q, Dong J, Liu Y, Dou R, Xue Q. Homo-Site Nucleation Growth of Twisted Bilayer MoS 2 with Commensurate Angles. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2408227. [PMID: 39072861 DOI: 10.1002/adma.202408227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2024] [Indexed: 07/30/2024]
Abstract
Moiré superlattices, composed of two layers of transition metal dichalcogenides with a relative twist angle, provide a novel platform for exploring the correlated electronic phases and excitonic physics. Here, a gas-flow perturbation chemical vapor deposition (CVD) approach is demonstrated to directly grow MoS2 bilayer with versatile twist angles. It is found that the formation of twisted bilayer MoS2 homostructures sensitively depends on the gas-flow perturbation modes, correspondingly featuring the nucleation sites of the second layer at the same (homo-site) as or at the different (hetero-site) from that of the first layer. The commensurate twist angle of ≈22° in homo-site nucleation strategy accounts for ≈16% among the broad range of twist angles due to its low formation energy, which is in consistence with the theoretical calculation. More importantly, moiré interlayer excitons with the enhanced photoluminescence (PL) intensity and the prolonged lifetime are evidenced in the twisted bilayer MoS2 with a commensurate angle of 22°, which is owing to the reason that the strong moiré potential facilitates the interlayer excitons to be trapped in the moiré superlattices. The work provides a feasible route to controllably built twisted MoS2 homostructures with strong moiré potential to investigate the correlated physics in twistronics systems.
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Affiliation(s)
- Jun Zhou
- School of Physics and Astronomy, Beijing Normal University, Beijing, 100875, P. R. China
| | - Haojie Huang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Zihan Zhao
- Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University, Beijing, 100875, P. R. China
| | - Zhenglong Dou
- Key Laboratory of Artificial Micro- and Nano-Structures of the Ministry of Education, Hubei Nuclear Solid Physics Key Laboratory, School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Li Zhou
- Key Laboratory of Artificial Micro- and Nano-Structures of the Ministry of Education, Hubei Nuclear Solid Physics Key Laboratory, School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China
| | - Tiantian Zhang
- School of Physics and Astronomy, Beijing Normal University, Beijing, 100875, P. R. China
| | - Zhiheng Huang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Yibiao Feng
- School of Physics and Astronomy, Beijing Normal University, Beijing, 100875, P. R. China
| | - Dongxia Shi
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Nan Liu
- Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University, Beijing, 100875, P. R. China
| | - Jian Yang
- School of Physics and Astronomy, Beijing Normal University, Beijing, 100875, P. R. China
| | - J C Nie
- School of Physics and Astronomy, Beijing Normal University, Beijing, 100875, P. R. China
| | - Ququan Wang
- Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, P. R. China
| | - Jichen Dong
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Yunqi Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Ruifen Dou
- School of Physics and Astronomy, Beijing Normal University, Beijing, 100875, P. R. China
| | - Qikun Xue
- Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, P. R. China
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4
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Wu K, He W, Zhong H, Wu S, Zhou H, Yuan S, Zhang S, Xu H. Helicity-Resolved Vibrational Coupling in Twist WS 2/WSe 2 Heterostructures. ACS APPLIED MATERIALS & INTERFACES 2024; 16:44186-44192. [PMID: 39109859 DOI: 10.1021/acsami.4c06488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/23/2024]
Abstract
Helicity-resolved Raman spectra can provide an intricate view into lattice structural details. Through the analysis of peak positions, intensities, and circular polarized Raman signals, a wealth of information about chiral structure arrangement within the moiré superlattice, interlayer interaction strength, polarizability change in chemical bond, and beyond can be unveiled. However, the relationship between the circular polarization of high-frequency Raman and twist angle is still not clear. Here, we utilize helicity-resolved Raman spectroscopy to explore the interlayer interactions and the effect of the moiré superlattice in WS2/WSe2 heterostructures. For the out-of-plane Raman mode A1g of WS2 (A1g and 1E2g of WSe2), its intensity is significantly enhanced (suppressed) in WS2/WSe2 heterostructures when θ is less than 10° or greater than 50°. This observation could be attributed to the large polarizability changes in both W-S and W-Se covalent bonds. The circular polarization of 2LA(M) in WSe2 of the WS2/WSe2 heterostructure (θ < 10° or θ > 50°) is significantly enhanced compared to that of 2LA(M) in the monolayer WSe2. We deduce that the circular polarization of the Raman mode correlates with the proportion of high-symmetry area within a supercell of the moiré lattice. Our findings improve the understanding of twist-angle-modulated Raman modes in TMD heterostructures.
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Affiliation(s)
- Ke Wu
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
- School of Sciences, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Wenyingdi He
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
| | - Hongxia Zhong
- School of Mathematics and Physics, China University of Geosciences, Wuhan 430074, China
| | - Shutong Wu
- School of Sciences, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Hongzhi Zhou
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou, Zhejiang 311200, China
| | - Shengjun Yuan
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
- Wuhan Institute of Quantum Technology, Wuhan 430206, China
| | - Shunping Zhang
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
- Wuhan Institute of Quantum Technology, Wuhan 430206, China
| | - Hongxing Xu
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
- School of Microelectronics, Wuhan University, Wuhan 430072, China
- Institute of Quantum Materials and Physics, Henan Academy of Sciences, Zhengzhou 450046, China
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5
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Hu X, Wang Y, Yuan J, Liao X, Zhou Y. Spectroscopic Analysis on Different Stacking Configurations of Multilayered MoSe 2. MATERIALS (BASEL, SWITZERLAND) 2024; 17:3998. [PMID: 39203176 PMCID: PMC11356233 DOI: 10.3390/ma17163998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2024] [Revised: 08/05/2024] [Accepted: 08/08/2024] [Indexed: 09/03/2024]
Abstract
Transition metal dichalcogenides (TMDs) are drawing significant attention due to their intriguing photoelectric properties, and these interesting properties are closely related to the number of layers. Obtaining layer-controlled and high-quality TMD is still a challenge. In this context, we use the salt-assisted chemical vapor deposition to grow multilayered MoSe2 flake and characterize it by Raman spectroscopy, second harmonic generation, and photon luminescence. Spectroscopic analysis is an effective way to characterize the stacking order and optoelectronic properties of two-dimensional materials. Notably, the corresponding mapping reflects the film quality and homogeneity. We found that the grown continuous monolayer, bilayer, and trilayer of MoSe2 sheets with different stacking orders exhibit distinctive features. For bilayer MoSe2, the most stable stacking configurations are the AA' and AB order. And the uniformity of the spectroscopy maps demonstrates the high quality of the stacked MoSe2 sheets.
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Affiliation(s)
- Xiang Hu
- School of Physics and Materials Science, Nanchang University, Nanchang 330031, China (J.Y.); (Y.Z.)
- Jiangxi Key Laboratory for Two-Dimensional Materials, Nanchang University, Nanchang 330031, China
| | - Yong Wang
- School of Physics and Materials Science, Nanchang University, Nanchang 330031, China (J.Y.); (Y.Z.)
- Jiangxi Key Laboratory for Two-Dimensional Materials, Nanchang University, Nanchang 330031, China
| | - Jiaren Yuan
- School of Physics and Materials Science, Nanchang University, Nanchang 330031, China (J.Y.); (Y.Z.)
- Jiangxi Key Laboratory for Two-Dimensional Materials, Nanchang University, Nanchang 330031, China
| | - Xiaxia Liao
- School of Physics and Materials Science, Nanchang University, Nanchang 330031, China (J.Y.); (Y.Z.)
- Jiangxi Key Laboratory for Two-Dimensional Materials, Nanchang University, Nanchang 330031, China
| | - Yangbo Zhou
- School of Physics and Materials Science, Nanchang University, Nanchang 330031, China (J.Y.); (Y.Z.)
- Jiangxi Key Laboratory for Two-Dimensional Materials, Nanchang University, Nanchang 330031, China
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6
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Cao MF, Peng XH, Zhao XJ, Bao YF, Xiao YH, Wu SS, Wang J, Lu Y, Wang M, Wang X, Lin KQ, Ren B. Ultralow-Frequency Tip-Enhanced Raman Scattering Discovers Nanoscale Radial Breathing Mode on Strained 2D Semiconductors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2405433. [PMID: 39007283 DOI: 10.1002/adma.202405433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 06/25/2024] [Indexed: 07/16/2024]
Abstract
Collective excitations including plasmons, magnons, and layer-breathing vibration modes emerge at an ultralow frequency (<1 THz) and are crucial for understanding van der Waals materials. Strain at the nanoscale can drastically change the property of van der Waals materials and create localized states like quantum emitters. However, it remains unclear how nanoscale strain changes collective excitations. Herein, ultralow-frequency tip-enhanced Raman spectroscopy (TERS) with sub-10 nm resolution under ambient conditions is developed to explore the localized collective excitation on monolayer semiconductors with nanoscale strains. A new vibrational mode is discovered at around 12 cm-1 (0.36 THz) on monolayer MoSe2 nanobubbles and it is identified as the radial breathing mode (RBM) of the curved monolayer. The correlation is determined between the RBM frequency and the strain by simultaneously performing deterministic nanoindentation and TERS measurement on monolayer MoSe2. The generality of the RBM in nanoscale curved monolayer WSe2 and bilayer MoSe2 is demonstrated. Using the RBM frequency, the strain of the monolayer MoSe2 on the nanoscale can be mapped. Such an ultralow-frequency vibration from curved van der Waals materials provides a new approach to study nanoscale strains and points to more localized collective excitations to be discovered at the nanoscale.
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Affiliation(s)
- Mao-Feng Cao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Xiao-Hui Peng
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Xiao-Jiao Zhao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Yi-Fan Bao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Yuan-Hui Xiao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Si-Si Wu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Jun Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Yao Lu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Miao Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Xiang Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
- Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province, Xiamen, 361102, China
| | - Kai-Qiang Lin
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
- Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province, Xiamen, 361102, China
| | - Bin Ren
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
- Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province, Xiamen, 361102, China
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7
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Yoon Y, Lu Z, Uzundal C, Qi R, Zhao W, Chen S, Feng Q, Kim W, Naik MH, Watanabe K, Taniguchi T, Louie SG, Crommie MF, Wang F. Terahertz phonon engineering with van der Waals heterostructures. Nature 2024; 631:771-776. [PMID: 38926584 DOI: 10.1038/s41586-024-07604-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 05/24/2024] [Indexed: 06/28/2024]
Abstract
Phonon engineering at gigahertz frequencies forms the foundation of microwave acoustic filters1, acousto-optic modulators2 and quantum transducers3,4. Terahertz phonon engineering could lead to acoustic filters and modulators at higher bandwidth and speed, as well as quantum circuits operating at higher temperatures. Despite their potential, methods for engineering terahertz phonons have been limited due to the challenges of achieving the required material control at subnanometre precision and efficient phonon coupling at terahertz frequencies. Here we demonstrate the efficient generation, detection and manipulation of terahertz phonons through precise integration of atomically thin layers in van der Waals heterostructures. We used few-layer graphene as an ultrabroadband phonon transducer that converts femtosecond near-infrared pulses to acoustic-phonon pulses with spectral content up to 3 THz. A monolayer WSe2 is used as a sensor. The high-fidelity readout was enabled by the exciton-phonon coupling and strong light-matter interactions. By combining these capabilities in a single heterostructure and detecting responses to incident mechanical waves, we performed terahertz phononic spectroscopy. Using this platform, we demonstrate high-Q terahertz phononic cavities and show that a WSe2 monolayer embedded in hexagonal boron nitride can efficiently block the transmission of terahertz phonons. By comparing our measurements to a nanomechanical model, we obtained the force constants at the heterointerfaces. Our results could enable terahertz phononic metamaterials for ultrabroadband acoustic filters and modulators and could open new routes for thermal engineering.
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Affiliation(s)
- Yoseob Yoon
- Department of Physics, University of California, Berkeley, CA, USA.
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Department of Mechanical and Industrial Engineering, Northeastern University, Boston, MA, USA.
| | - Zheyu Lu
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Graduate Group in Applied Science and Technology, University of California, Berkeley, CA, USA
| | - Can Uzundal
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Chemistry, University of California, Berkeley, CA, USA
| | - Ruishi Qi
- Department of Physics, University of California, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Wenyu Zhao
- Department of Physics, University of California, Berkeley, CA, USA
| | - Sudi Chen
- Department of Physics, University of California, Berkeley, CA, USA
- Kavli Energy NanoScience Institute, Berkeley, CA, USA
| | - Qixin Feng
- Department of Physics, University of California, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Woochang Kim
- Department of Physics, University of California, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Mit H Naik
- Department of Physics, University of California, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Kenji Watanabe
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Steven G Louie
- Department of Physics, University of California, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Michael F Crommie
- Department of Physics, University of California, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Kavli Energy NanoScience Institute, Berkeley, CA, USA
| | - Feng Wang
- Department of Physics, University of California, Berkeley, CA, USA.
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Kavli Energy NanoScience Institute, Berkeley, CA, USA.
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8
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Zhang Y, Long R. Nuclear Quantum Effects Accelerate Charge Separation and Recombination in g-C 3N 4/TiO 2 Heterojunctions. J Phys Chem Lett 2024; 15:6002-6009. [PMID: 38814291 DOI: 10.1021/acs.jpclett.4c01329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
We combined ring-polymer molecular dynamics (MD) and ab initio MD with nonadiabatic MD to study the effects of nuclear quantum effects (NQEs) on interlayer electron transfer and electron-hole recombination at the g-C3N4/TiO2 interface. Our simulations indicate that NQEs significantly affect electron transfer and electron-hole recombination dynamics, accelerating both processes. NQEs deform the g-C3N4 layer and expedite the movement of carbon and nitrogen atoms, thus, enhancing charge delocalization and interlayer coupling. This improved overlap between electronic state wave functions enhances nonadiabatic couplings, facilitating electron transfer and recombination. In addition to the enhanced nonadiabatic couplings accelerating electron transfer, the presence of NQEs narrows the energy gap and delays decoherence by mitigating overall fluctuations, because of restricted TiO2 movements overwhelming enhanced g-C3N4 fluctuations, thereby making the recombination faster. This work provides valuable insights into NQEs in light-element systems and contributes to guiding the development of highly efficient photocatalysts.
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Affiliation(s)
- Yitong Zhang
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China
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9
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Klein B, Liang L, Meunier V. Low-frequency Raman active modes of twisted bilayer MoS 2. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:365301. [PMID: 38788746 DOI: 10.1088/1361-648x/ad5093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Accepted: 05/24/2024] [Indexed: 05/26/2024]
Abstract
We study the low-frequency Raman active modes of twisted bilayer MoS2for several twist angles using a force-field approach and a parametrized bond polarizability model. We show that twist angles near high-symmetry stacking configurations exhibit stacking frustration that leads to significant buckling of the moiré superlattice. We find that atomic relaxation due to the twist is of prime importance. The periodic displacement of the Mo atoms shows the realization of a soliton network, and in turn, leads to the emergence of a number of frequency modes not seen in the high-symmetry stacking systems. Some of the modes are only seen in theXZRaman polarization setup while others are seen in theXYsetup. The symmetry of the normal modes, and how this affects the Raman tensors is examined in detail.
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Affiliation(s)
- Brandon Klein
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180, United States of America
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218, United States of America
| | - Liangbo Liang
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - Vincent Meunier
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180, United States of America
- Department of Engineering Science and Mechanics, The University of Pennsylvania, University Park, PA, 16802, United States of America
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10
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Fox C, Mao Y, Zhang X, Wang Y, Xiao J. Stacking Order Engineering of Two-Dimensional Materials and Device Applications. Chem Rev 2024; 124:1862-1898. [PMID: 38150266 DOI: 10.1021/acs.chemrev.3c00618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
Stacking orders in 2D van der Waals (vdW) materials dictate the relative sliding (lateral displacement) and twisting (rotation) between atomically thin layers. By altering the stacking order, many new ferroic, strongly correlated and topological orderings emerge with exotic electrical, optical and magnetic properties. Thanks to the weak vdW interlayer bonding, such highly flexible and energy-efficient stacking order engineering has transformed the design of quantum properties in 2D vdW materials, unleashing the potential for miniaturized high-performance device applications in electronics, spintronics, photonics, and surface chemistry. This Review provides a comprehensive overview of stacking order engineering in 2D vdW materials and their device applications, ranging from the typical fabrication and characterization methods to the novel physical properties and the emergent slidetronics and twistronics device prototyping. The main emphasis is on the critical role of stacking orders affecting the interlayer charge transfer, orbital coupling and flat band formation for the design of innovative materials with on-demand quantum properties and surface potentials. By demonstrating a correlation between the stacking configurations and device functionality, we highlight their implications for next-generation electronic, photonic and chemical energy conversion devices. We conclude with our perspective of this exciting field including challenges and opportunities for future stacking order engineering research.
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Affiliation(s)
- Carter Fox
- Department of Materials Science and Engineering, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
- Department of Physics, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Yulu Mao
- Department of Electrical and Computer Engineering, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Xiang Zhang
- Faculty of Science, University of Hong Kong, Hong Kong, China
- Faculty of Engineering, University of Hong Kong, Hong Kong, China
| | - Ying Wang
- Department of Materials Science and Engineering, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
- Department of Physics, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
- Department of Electrical and Computer Engineering, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Jun Xiao
- Department of Materials Science and Engineering, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
- Department of Physics, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
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11
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Pakdel S, Rasmussen A, Taghizadeh A, Kruse M, Olsen T, Thygesen KS. High-throughput computational stacking reveals emergent properties in natural van der Waals bilayers. Nat Commun 2024; 15:932. [PMID: 38296946 PMCID: PMC10831070 DOI: 10.1038/s41467-024-45003-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 01/12/2024] [Indexed: 02/02/2024] Open
Abstract
Stacking of two-dimensional (2D) materials has emerged as a facile strategy for realising exotic quantum states of matter and engineering electronic properties. Yet, developments beyond the proof-of-principle level are impeded by the vast size of the configuration space defined by layer combinations and stacking orders. Here we employ a density functional theory (DFT) workflow to calculate interlayer binding energies of 8451 homobilayers created by stacking 1052 different monolayers in various configurations. Analysis of the stacking orders in 247 experimentally known van der Waals crystals is used to validate the workflow and determine the criteria for realisable bilayers. For the 2586 most stable bilayer systems, we calculate a range of electronic, magnetic, and vibrational properties, and explore general trends and anomalies. We identify an abundance of bistable bilayers with stacking order-dependent magnetic or electrical polarisation states making them candidates for slidetronics applications.
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Affiliation(s)
- Sahar Pakdel
- CAMD, Computational Atomic-Scale Materials Design, Department of Physics, Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
| | - Asbjørn Rasmussen
- CAMD, Computational Atomic-Scale Materials Design, Department of Physics, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Alireza Taghizadeh
- CAMD, Computational Atomic-Scale Materials Design, Department of Physics, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Mads Kruse
- CAMD, Computational Atomic-Scale Materials Design, Department of Physics, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Thomas Olsen
- CAMD, Computational Atomic-Scale Materials Design, Department of Physics, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Kristian S Thygesen
- CAMD, Computational Atomic-Scale Materials Design, Department of Physics, Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
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12
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Zhu H, Chen B, Yakovlev VV, Zhang D. Time-resolved vibrational dynamics: Novel opportunities for sensing and imaging. Talanta 2024; 266:125046. [PMID: 37595525 DOI: 10.1016/j.talanta.2023.125046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 07/19/2023] [Accepted: 08/05/2023] [Indexed: 08/20/2023]
Abstract
The evolution of time-resolved spectroscopies has resulted in significant advancements across numerous scientific disciplines, particularly those concerned with molecular electronic states. However, the intricacy of molecular vibrational spectroscopies, which provide comprehensive molecular-level information within complex structures, has presented considerable challenges due to the ultrashort dephasing time. Over recent decades, an increasing focus has been placed on exploring the temporal progression of bond vibrations, thereby facilitating an improved understanding of energy redistribution within and between molecules. This review article focuses on an array of time-resolved detection methodologies, each distinguished by unique technological attributes that offer exclusive capabilities for investigating the physical phenomena propelled by molecular vibrational dynamics. In summary, time-resolved vibrational spectroscopy emerges as a potent instrument for deciphering the dynamic behavior of molecules. Its potential for driving future progress across fields as diverse as biology and materials science is substantial, marking a promising future for this innovative tool.
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Affiliation(s)
- Hanlin Zhu
- Interdisciplinary Center for Quantum Information, Zhejiang Province Key Laboratory of Quantum Technology and Device, and Department of Physics, Zhejiang University, Hangzhou, Zhejiang, 310028, China.
| | - Bo Chen
- Interdisciplinary Center for Quantum Information, Zhejiang Province Key Laboratory of Quantum Technology and Device, and Department of Physics, Zhejiang University, Hangzhou, Zhejiang, 310028, China.
| | - Vladislav V Yakovlev
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA; Department of Physics and Astronomy, Texas A&M University, College Station, TX, 77843, USA; Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX, 77843, USA.
| | - Delong Zhang
- Interdisciplinary Center for Quantum Information, Zhejiang Province Key Laboratory of Quantum Technology and Device, and Department of Physics, Zhejiang University, Hangzhou, Zhejiang, 310028, China.
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13
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Jahng J, Lee S, Hong SG, Lee CJ, Menabde SG, Jang MS, Kim DH, Son J, Lee ES. Characterizing and controlling infrared phonon anomaly of bilayer graphene in optical-electrical force nanoscopy. LIGHT, SCIENCE & APPLICATIONS 2023; 12:281. [PMID: 37996403 PMCID: PMC10667502 DOI: 10.1038/s41377-023-01320-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 09/29/2023] [Accepted: 10/30/2023] [Indexed: 11/25/2023]
Abstract
We, for the first time, report the nanoscopic imaging study of anomalous infrared (IR) phonon enhancement of bilayer graphene, originated from the charge imbalance between the top and bottom layers, resulting in the enhancement of E1u mode of bilayer graphene near 0.2 eV. We modified the multifrequency atomic force microscope platform to combine photo-induced force microscope with electrostatic/Kelvin probe force microscope constituting a novel hybrid nanoscale optical-electrical force imaging system. This enables to observe a correlation between the IR response, doping level, and topographic information of the graphene layers. Through the nanoscale spectroscopic image measurements, we demonstrate that the charge imbalance at the graphene interface can be controlled by chemical (doping effect via Redox mechanism) and mechanical (triboelectric effect by the doped cantilever) approaches. Moreover, we can also diagnosis the subsurface cracks on the stacked few-layer graphene at nanoscale, by monitoring the strain-induced IR phonon shift. Our approach provides new insights into the development of graphene-based electronic and photonic devices and their potential applications.
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Affiliation(s)
- Junghoon Jahng
- Hyperspectral Nano-imaging Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea.
| | - Sunho Lee
- Hyperspectral Nano-imaging Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
- Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Seong-Gu Hong
- Multiscale Mechanical Properties Measurement Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Chang Jun Lee
- Multiscale Mechanical Properties Measurement Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
- School of Mechanical Engineering, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Sergey G Menabde
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Min Seok Jang
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Dong-Hyun Kim
- Functional Composite Materials Research Center, Korea Institute of Science and Technology, Jeonbuk, 55324, Republic of Korea
- SKKU Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Jangyup Son
- Functional Composite Materials Research Center, Korea Institute of Science and Technology, Jeonbuk, 55324, Republic of Korea
- Division of Nano & Information Technology, KIST School, University of Science and Technology, Seoul, 02792, Republic of Korea
| | - Eun Seong Lee
- Hyperspectral Nano-imaging Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea.
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14
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Ubaldini A, Cicconi F, Rizzo A, Salvi S, Cuzzola V, Gennerini F, Bruni S, Marghella G, Gessi A, Falsini N. Preparation and Characterization of Isostructural Na 2MoO 4 and Na 2WO 4 and a Study of the Composition of Their Mixed System. Molecules 2023; 28:6602. [PMID: 37764377 PMCID: PMC10538176 DOI: 10.3390/molecules28186602] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/01/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
Na2MoO4 and Na2WO4 are isostructural semiconductors, belonging to the spinel class. They have interesting properties and find applications in numerous sectors. These properties can be tuned by controlling the composition of their solid solutions. Here, different methods to obtain these compounds are presented, both wet and solid-state synthesis. The obtained results show a possible dependence of the material properties on the chosen synthesis method. The pure compounds and their mixtures were characterized by Raman spectroscopy, scanning electron microscopy, and X-ray diffraction.
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Affiliation(s)
- Alberto Ubaldini
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Via Martiri di Monte Sole 4, 40129 Bologna, Italy; (A.R.); (S.B.); (G.M.); (A.G.); (N.F.)
| | - Flavio Cicconi
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), C.R. Brasimone, 40032 Camugnano, Italy; (F.C.); (S.S.); (V.C.)
| | - Antonietta Rizzo
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Via Martiri di Monte Sole 4, 40129 Bologna, Italy; (A.R.); (S.B.); (G.M.); (A.G.); (N.F.)
| | - Stefano Salvi
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), C.R. Brasimone, 40032 Camugnano, Italy; (F.C.); (S.S.); (V.C.)
| | - Vincenzo Cuzzola
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), C.R. Brasimone, 40032 Camugnano, Italy; (F.C.); (S.S.); (V.C.)
| | - Francesco Gennerini
- Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi” (DEI), Biomedical Engineering, Cesena Campus, Alma Mater Studiorum University of Bologna, Via dell’Università 50, 47522 Cesena, Italy;
| | - Stefania Bruni
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Via Martiri di Monte Sole 4, 40129 Bologna, Italy; (A.R.); (S.B.); (G.M.); (A.G.); (N.F.)
| | - Giuseppe Marghella
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Via Martiri di Monte Sole 4, 40129 Bologna, Italy; (A.R.); (S.B.); (G.M.); (A.G.); (N.F.)
| | - Alessandro Gessi
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Via Martiri di Monte Sole 4, 40129 Bologna, Italy; (A.R.); (S.B.); (G.M.); (A.G.); (N.F.)
| | - Naomi Falsini
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Via Martiri di Monte Sole 4, 40129 Bologna, Italy; (A.R.); (S.B.); (G.M.); (A.G.); (N.F.)
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15
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Hao H, Lin ML, Xu B, Wu H, Wang Y, Peng H, Tan PH, Tong L, Zhang J. Enhanced Layer-Breathing Modes in van der Waals Heterostructures Based on Twisted Bilayer Graphene. ACS NANO 2023. [PMID: 37267416 DOI: 10.1021/acsnano.3c00022] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The characterization of interlayer coupling in two-dimensional van der Waals heterostructures (vdWHs) is essential to understand their quantum behaviors and structural functionalities. Interlayer shear and layer-breathing (LB) phonons carry rich information on interlayer interaction, but they are usually too weak to be detected via standard Raman spectroscopy due to the weak electron-phonon coupling (EPC). Here, we report a universal strategy to enhance LB modes of vdWHs based on twisted bilayer graphene (tBLG). In both tBLG/hBN and tBLG/MoS2 vdWHs, the resonantly excited electrons in tBLG can strongly couple to LB phonons extended over the entire layers in the vdWHs, whose resonance condition is tunable by the twist angle of tBLG. In vdWHs containing twisted graphene layers with multiple twisted interfaces, the EPC of LB phonons coming from the collective LB vibrations of entire heterostructure layers can be tuned by resonant excitation of programmable van Hove singularities according to each twisted interface. The universality and tunability of enhanced LB phonons by tBLG make it a promising method to investigate EPC and interlayer interaction in related vdWHs.
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Affiliation(s)
- He Hao
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, 100871, Beijing, China
| | - Miao-Ling Lin
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, 100083, Beijing, China
| | - Bo Xu
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, 100871, Beijing, China
- Academy for Advanced Interdisciplinary Studies, Peking University, 100871, Beijing, China
| | - Heng Wu
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, 100083, Beijing, China
| | - Yuechen Wang
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, 100871, Beijing, China
- Academy for Advanced Interdisciplinary Studies, Peking University, 100871, Beijing, China
| | - Hailin Peng
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, 100871, Beijing, China
| | - Ping-Heng Tan
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, 100083, Beijing, China
| | - Lianming Tong
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, 100871, Beijing, China
| | - Jin Zhang
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, 100871, Beijing, China
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16
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Zhou J, Cui J, Du S, Zhao Z, Guo J, Li S, Zhang W, Liu N, Li X, Bai Q, Guo Y, Mi S, Cheng Z, He L, Nie JC, Yang Y, Dou R. A natural indirect-to-direct band gap transition in artificially fabricated MoS 2 and MoSe 2 flowers. NANOSCALE 2023; 15:7792-7802. [PMID: 37021968 DOI: 10.1039/d3nr00477e] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Twisted bilayer (tB) transition metal dichalcogenide (TMD) structures formed from two pieces of a periodic pattern overlaid with a relative twist manifest novel electronic and optical properties and correlated electronic phenomena. Here, twisted flower-like MoS2 and MoSe2 bilayers were artificially fabricated by the chemical vapor deposition (CVD) method. Photoluminescence (PL) studies demonstrated that an energy band structural transition from the indirect gap to the direct gap happened in the region away from the flower center in tB MoS2 (MoSe2) flower patterns, accompanied by an enhanced PL intensity. The indirect-to-direct-gap transition in the tB-MoS2 (MoSe2) flower dominantly originated from a gradually enlarged interlayer spacing and thus, interlayer decoupling during the spiral growth of tB flower patterns. Meanwhile, the expanded interlayer spacing resulted in a decreased effective mass of the electrons. This means that the charged exciton (trion) population was reduced and the neutral exciton density was increased to obtain the upgraded PL intensity in the off-center region. Our experimental results were further evidenced by the density functional theory (DFT) calculations of the energy band structures and the effective masses of electrons and holes for the artificial tB-MoS2 flower with different interlayer spacings. The single-layer behavior of tB flower-like homobilayers provided a viable route to finely manipulate the energy band gap and the corresponding exotic optical properties by locally tuning the stacked structures and to satisfy the real requirement in TMD-based optoelectronic devices.
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Affiliation(s)
- Jun Zhou
- Department of Physics, Beijing Normal, University, Beijing, 100875, China.
| | - Juan Cui
- LCP, Inst Appl Phys & Computation Math, Beijing 100088, China.
| | - Shuo Du
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Zihan Zhao
- Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University, 100875, China
| | - Jianfeng Guo
- Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, P. R. China
| | - Songyang Li
- Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, P. R. China
| | - Weifeng Zhang
- Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University, 100875, China
| | - Nan Liu
- Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University, 100875, China
| | - Xiaotian Li
- Department of Physics, Beijing Normal, University, Beijing, 100875, China.
| | - Qinghu Bai
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yang Guo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Shuo Mi
- Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, P. R. China
| | - Zhihai Cheng
- Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, P. R. China
| | - Lin He
- Department of Physics, Beijing Normal, University, Beijing, 100875, China.
| | - J C Nie
- Department of Physics, Beijing Normal, University, Beijing, 100875, China.
| | - Yu Yang
- LCP, Inst Appl Phys & Computation Math, Beijing 100088, China.
| | - Ruifen Dou
- Department of Physics, Beijing Normal, University, Beijing, 100875, China.
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17
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Das D, Manna J, Bhattacharyya TK. Efficient Hydrogen Evolution via 1T-MoS 2 /Chlorophyll-a Heterostructure: Way Toward Metal Free Green Catalyst. SMALL METHODS 2023; 7:e2201446. [PMID: 36807895 DOI: 10.1002/smtd.202201446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/20/2022] [Indexed: 06/18/2023]
Abstract
Electrocatalytic hydrogen evolution reaction (HER) is regarded as a sustainable and green way for H2 generation, which faces a great challenge in designing highly active, stable electrocatalysts to replace the state-of-art noble metal-platinum catalysts. 1T MoS2 is highly promising in this regard, but the synthesis and stability of this is a particularly pressing task. Here, a phase engineering strategy has been proposed to achieve a stable, high-percentage (88%) 1T MoS2 /chlorophyll-a hetero-nanostructure, through a photo-induced donation of anti-bonding electrons from chlorophyll-a (CHL-a) highest occupied molecular orbital to 2H MoS2 lowest unoccupied molecular orbital. The resultant catalyst has abundant binding sites provided by the coordination of magnesium atom in the CHL-a macro-cycle, featuring higher binding strength and low Gibbs-free energy. This metal-free heterostructure exhibits excellent stability via band renormalization of Mo 4d orbital which creates the pseudogap-like structure by lifting the degeneracy of projected density of state with 4S in 1T MoS2 . It shows extremely low overpotential, toward the acidic HER (68 mV at the current density of 10 mA cm-2 ), very close to the Pt/C catalyst (53 mV). The high electrochemical-surface-area and electrochemical turnover frequency support enhanced active sites along with near zero Gibbs free energy. Such a surface-reconstruction strategy provides a new avenue toward the production of efficient non-noble-metal-catalysts for the HER with the aim of green-hydrogen production.
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Affiliation(s)
- Debmallya Das
- School of Nano-Science and Technology, Indian Institute of Technology, Kharagpur, West Bengal, 721302, India
| | - Jhimli Manna
- Department of Electronics and Communication Engineering, Indian Institute of Technology, Kharagpur, West Bengal, 721302, India
| | - Tarun Kanti Bhattacharyya
- Department of Electronics and Communication Engineering, Indian Institute of Technology, Kharagpur, West Bengal, 721302, India
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18
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In situ electrochemical Raman spectroscopy and ab initio molecular dynamics study of interfacial water on a single-crystal surface. Nat Protoc 2023; 18:883-901. [PMID: 36599962 DOI: 10.1038/s41596-022-00782-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 09/12/2022] [Indexed: 01/05/2023]
Abstract
The dynamics and chemistry of interfacial water are essential components of electrocatalysis because the decomposition and formation of water molecules could dictate the protonation and deprotonation processes on the catalyst surface. However, it is notoriously difficult to probe interfacial water owing to its location between two condensed phases, as well as the presence of external bias potentials and electrochemically induced reaction intermediates. An atomically flat single-crystal surface could offer an attractive platform to resolve the internal structure of interfacial water if advanced characterization tools are developed. To this end, here we report a protocol based on the combination of in situ Raman spectroscopy and ab initio molecular dynamics (AIMD) simulations to unravel the directional molecular features of interfacial water. We present the procedures to prepare single-crystal electrodes, construct a Raman enhancement mode with shell-isolated nanoparticle, remove impurities, eliminate the perturbation from bulk water and dislodge the hydrogen bubbles during in situ electrochemical Raman experiments. The combination of the spectroscopic measurements with AIMD simulation results provides a roadmap to decipher the potential-dependent molecular orientation of water at the interface. We have prepared a detailed guideline for the application of combined in situ Raman and AIMD techniques; this procedure may take a few minutes to several days to generate results and is applicable to a variety of disciplines ranging from surface science to energy storage to biology.
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19
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Li X, Shi X, Marian D, Soriano D, Cusati T, Iannaccone G, Fiori G, Guo Q, Zhao W, Wu Y. Rhombohedral-stacked bilayer transition metal dichalcogenides for high-performance atomically thin CMOS devices. SCIENCE ADVANCES 2023; 9:eade5706. [PMID: 36791201 PMCID: PMC9931205 DOI: 10.1126/sciadv.ade5706] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
Van der Waals coupling with different stacking configurations is emerging as a powerful method to tune the optical and electronic properties of atomically thin two-dimensional materials. Here, we investigate 3R-stacked transition-metal dichalcogenides as a possible option for high-performance atomically thin field-effect transistors (FETs). We report that the effective mobility of 3R bilayer WS2 (WSe2) is 65% (50%) higher than that of 2H WS2 (WSe2). The 3R bilayer WS2 n-type FET exhibits a high on-state current of 480 μA/μm at Vds = 1 V and an ultralow on-state resistance of 1 kilohm·μm. Our observations, together with multiscale simulations, reveal that these improvements originate from the strong interlayer coupling in the 3R stacking, which is reflected in a higher conductance compared to the 2H stacking. Our method provides a general and scalable route toward advanced channel materials in future electronic devices for ultimate scaling, especially for complementary metal oxide semiconductor applications.
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Affiliation(s)
- Xuefei Li
- Wuhan National High Magnetic Field Center and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xinhang Shi
- Wuhan National High Magnetic Field Center and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Damiano Marian
- Dipartimento di Ingegneria dell’Informazione, Università di Pisa, Via Girolamo Caruso 16, Pisa 56122, Italia
| | - David Soriano
- Dipartimento di Ingegneria dell’Informazione, Università di Pisa, Via Girolamo Caruso 16, Pisa 56122, Italia
- Departamento de Física Aplicada, Universidad de Alicante, San Vicente del Raspeig 03690, Spain
| | - Teresa Cusati
- Dipartimento di Ingegneria dell’Informazione, Università di Pisa, Via Girolamo Caruso 16, Pisa 56122, Italia
| | - Giuseppe Iannaccone
- Dipartimento di Ingegneria dell’Informazione, Università di Pisa, Via Girolamo Caruso 16, Pisa 56122, Italia
| | - Gianluca Fiori
- Dipartimento di Ingegneria dell’Informazione, Università di Pisa, Via Girolamo Caruso 16, Pisa 56122, Italia
| | - Qi Guo
- Wuhan National High Magnetic Field Center and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Wenjie Zhao
- Wuhan National High Magnetic Field Center and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yanqing Wu
- School of Integrated Circuits and Key Laboratory of Microelectronic Devices and Circuits (MOE), Peking University, Beijing 100871, China
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20
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Le CT, Lee JH, Kim D, Jang M, Yoon JY, Kim K, Jang JI, Seong MJ, Kim YS. Negative Valley Polarization of the Intralayer Exciton via One-Step Growth of H-Type Heterobilayer WS 2/MoS 2. ACS NANO 2023; 17:2629-2638. [PMID: 36688595 DOI: 10.1021/acsnano.2c10581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Vertical type II van der Waals heterobilayers of transition metal dichalcogenides (TMDs) have attracted wide attention due to their distinctive features mostly arising from the emergence of intriguing electronic structures that include moiré-related phenomena. Owing to strong spin-orbit coupling under a noncentrosymmetric environment, TMD heterobilayers host nonequivalent +K and -K valleys of contrasting Berry curvatures, which can be optically controlled by the helicity of optical excitation. The corresponding valley selection rules are well established by not only intralayer excitons but also interlayer excitons. Quite intriguingly, here, we experimentally demonstrate that unusual valley switching can be achieved using the lowest-lying intralayer excitons in H-type heterobilayer WS2/MoS2 prepared by one-step growth. This TMD combination provides an ideal case for interlayer coupling with an almost perfect lattice match, thereby also in the momentum space between +K and -K valleys in the H-type heterostructure. The underlying valley-switching mechanism can be understood by bright-to-dark conversion of initially created electrons in the valley of WS2, followed by interlayer charge transfer to the opposite valley in MoS2. Our suggested model is also confirmed by the absence of valley switching when the lowest-lying excitons in MoS2 are directly generated in the heterobilayer. In contrast to the H-type case, we show that no valley switching is observed from R-type heterobilayers prepared by the same method, where interlayer charge transfer does not occur between the opposite valleys. We compare the case with the series of valley polarization data from other heterobilayer combinations obtained under different excitation energies and temperatures. Our valley switching mechanism can be utilized for valley manipulation by controlling the excitation photon energy together with the photon helicity in valleytronic devices derived from H-type TMD heterobilayers.
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Affiliation(s)
- Chinh Tam Le
- Department of Physics and Energy Harvest-Storage Research Center, University of Ulsan, Ulsan44610, South Korea
| | - Je-Ho Lee
- Department of Physics, Chung-Ang University, Seoul06794, South Korea
| | - Donggyu Kim
- Department of Physics, Sogang University, Seoul04107, South Korea
| | - Myeongjin Jang
- Department of Physics, Yonsei University, Seoul03722, South Korea
| | - Jun-Yeong Yoon
- Department of Physics, Yonsei University, Seoul03722, South Korea
| | - Kwanpyo Kim
- Department of Physics, Yonsei University, Seoul03722, South Korea
| | - Joon I Jang
- Department of Physics, Sogang University, Seoul04107, South Korea
| | - Maeng-Je Seong
- Department of Physics, Chung-Ang University, Seoul06794, South Korea
| | - Yong Soo Kim
- Department of Physics and Energy Harvest-Storage Research Center, University of Ulsan, Ulsan44610, South Korea
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21
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Li G, Stefanczyk O, Kumar K, Mineo Y, Nakabayashi K, Ohkoshi SI. Low-Frequency Sub-Terahertz Absorption in Hg II -XCN-Fe II (X=S, Se) Coordination Polymers. Angew Chem Int Ed Engl 2023; 62:e202214673. [PMID: 36522797 DOI: 10.1002/anie.202214673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 12/14/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
Self-assembly FeII complexes of phenazine (Phen), quinoxaline (Qxn), and 4,4'-trimethylenedipyridine (Tmp) with tetrahedral building blocks of [HgII (XCN)4 ]2- (X=S or Se) formed six new high-dimensional frameworks with the general formula of [Fe(L)m ][Hg(XCN)4 ]⋅solvents (L=Phen, m/X=2/S, 1; L=Qxn, m/X=2/S, 2; L=Qxn, m/X=1/S, 3; L=Qxn, m/X=1/Se, 3-Se; L=Tmp, m/X=1/S, 4; and L=Tmp, m/X=1/Se, 4-Se). 1, 3, and 3-Se show an intense sub-terahertz (sub-THz) absorbance of around 0.60 THz due to vibrations of the solvent molecules coordinated to the FeII ions and crystallization organic molecules. In addition, crystals of 1, 4, and 4-Se display low-frequency Raman scattering with exceptionally low values of 0.44, 0.51, and 0.53 THz, respectively. These results indicate that heavy metal FeII -HgII systems are promising platforms to construct sub-THz absorbers.
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Affiliation(s)
- Guanping Li
- Department of Chemistry, School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Olaf Stefanczyk
- Department of Chemistry, School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Kunal Kumar
- Department of Chemistry, School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yuuki Mineo
- Department of Chemistry, School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Koji Nakabayashi
- Department of Chemistry, School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Shin-Ichi Ohkoshi
- Department of Chemistry, School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
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22
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Majchrzak PE, Liu Y, Volckaert K, Biswas D, Sahoo C, Puntel D, Bronsch W, Tuniz M, Cilento F, Pan XC, Liu Q, Chen YP, Ulstrup S. Van der Waals Engineering of Ultrafast Carrier Dynamics in Magnetic Heterostructures. NANO LETTERS 2023; 23:414-421. [PMID: 36607246 DOI: 10.1021/acs.nanolett.2c03075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Heterostructures composed of the intrinsic magnetic topological insulator MnBi2Te4 and its nonmagnetic counterpart Bi2Te3 host distinct surface electronic band structures depending on the stacking order and exposed termination. Here, we probe the ultrafast dynamical response of MnBi2Te4 and MnBi4Te7 following near-infrared optical excitation using time- and angle-resolved photoemission spectroscopy and disentangle surface from bulk dynamics based on density functional theory slab calculations of the surface-projected electronic structure. We gain access to the out-of-equilibrium charge carrier populations of both MnBi2Te4 and Bi2Te3 surface terminations of MnBi4Te7, revealing an instantaneous occupation of states associated with the Bi2Te3 surface layer followed by carrier extraction into the adjacent MnBi2Te4 layers with a laser fluence-tunable delay of up to 350 fs. The ensuing thermal relaxation processes are driven by phonon scattering with significantly slower relaxation times in the magnetic MnBi2Te4 septuple layers. The observed competition between interlayer charge transfer and intralayer phonon scattering demonstrates a method to control ultrafast charge transfer processes in MnBi2Te4-based van der Waals compounds.
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Affiliation(s)
- Paulina Ewa Majchrzak
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
| | - Yuntian Liu
- Department of Physics and Shenzhen Institute for Quantum Science and Engineering (SIQSE), Southern University of Science and Technology, Shenzhen 518055, China
| | - Klara Volckaert
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
| | - Deepnarayan Biswas
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
| | - Chakradhar Sahoo
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
| | - Denny Puntel
- Dipartimento di Fisica, Università degli Studi di Trieste, 34127 Trieste, Italy
| | - Wibke Bronsch
- Elettra - Sincrotrone Trieste S.C.p.A., 34149 Basovizza, Italy
| | - Manuel Tuniz
- Dipartimento di Fisica, Università degli Studi di Trieste, 34127 Trieste, Italy
| | | | - Xing-Chen Pan
- Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - Qihang Liu
- Department of Physics and Shenzhen Institute for Quantum Science and Engineering (SIQSE), Southern University of Science and Technology, Shenzhen 518055, China
| | - Yong P Chen
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
- Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
- Department of Physics and Astronomy, School of Electrical and Computer Engineering, and Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, Indiana 47907, United States
| | - Søren Ulstrup
- Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
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23
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Su J, Li X, Xu M, Zhang J, Liu X, Zheng X, Shi Y, Zhang Q. Enhancing Photodetection Ability of MoS 2 Nanoscrolls via Interface Engineering. ACS APPLIED MATERIALS & INTERFACES 2023; 15:3307-3316. [PMID: 36596237 DOI: 10.1021/acsami.2c18537] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Van der Waals semiconductors have been really confirmed in two-dimensional (2D) layered systems beyond the traditional limits of lattice-matching requirements. The extension of this concept to the 1D atomic level may generate intriguing physical functionalities due to its non-covalent bonding surface. However, whether the curvature of the lattice in such rolled-up structures affects their optoelectronic features or the performance of devices established on them remains an open question. Here, MoS2-based nanoscrolls were obtained by virtue of an alkaline solution-assisted method and the 0D/1D (BaTiO3/MoS2) strategy to tune their optoelectronic properties and improve the light sensing performance was explored. The capillary force generated by a drop of NaHCO3 solution could drive the delamination of nanosheets from the underlying substrate and a spontaneous rolling-up process. The package of BaTiO3 particles in MoS2 nanoscrolls has been evident by TEM image, and the optical characterizations were mirrored via micro-Raman spectroscopy and photoluminescence. These bare MoS2 nanoscrolls reveal a reduced photoresponse compared to the plane structures due to the curvature of the lattice. However, such BaTiO3/MoS2 nanoscrolls exhibit a significantly improved photodetection (Rhybrid = 73.9 A/W vs Ronly = 1.1 A/W and R2D = 1.5 A/W at 470 nm, 0.58 mW·cm-2), potentially due to the carrier extraction/injection occurring between BaTiO3 and MoS2. This study thereby provides an insight into 1D van der Waals material community and demonstrates a general approach to fabricate high-performance 1D van der Waals optoelectronic devices.
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Affiliation(s)
- Jun Su
- Center for Advanced Optoelectronic Materials, College of Materials and Environmental Engineering, Hangzhou Dianzi University (HDU), Hangzhou 310018, China
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, Hangzhou Dianzi University (HDU), Hangzhou 310018, P. R. China
| | - Xin Li
- Center for Advanced Optoelectronic Materials, College of Materials and Environmental Engineering, Hangzhou Dianzi University (HDU), Hangzhou 310018, China
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, Hangzhou Dianzi University (HDU), Hangzhou 310018, P. R. China
| | - Minxuan Xu
- Center for Advanced Optoelectronic Materials, College of Materials and Environmental Engineering, Hangzhou Dianzi University (HDU), Hangzhou 310018, China
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, Hangzhou Dianzi University (HDU), Hangzhou 310018, P. R. China
| | - Jian Zhang
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, Hangzhou Dianzi University (HDU), Hangzhou 310018, P. R. China
| | - Xiaolian Liu
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, Hangzhou Dianzi University (HDU), Hangzhou 310018, P. R. China
| | - Xin Zheng
- Center for Advanced Optoelectronic Materials, College of Materials and Environmental Engineering, Hangzhou Dianzi University (HDU), Hangzhou 310018, China
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, Hangzhou Dianzi University (HDU), Hangzhou 310018, P. R. China
| | - Yueqin Shi
- Center for Advanced Optoelectronic Materials, College of Materials and Environmental Engineering, Hangzhou Dianzi University (HDU), Hangzhou 310018, China
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, Hangzhou Dianzi University (HDU), Hangzhou 310018, P. R. China
| | - Qi Zhang
- Center for Advanced Optoelectronic Materials, College of Materials and Environmental Engineering, Hangzhou Dianzi University (HDU), Hangzhou 310018, China
- Key Laboratory of Novel Materials for Sensor of Zhejiang Province, Hangzhou Dianzi University (HDU), Hangzhou 310018, P. R. China
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24
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Tan QH, Li YM, Lai JM, Sun YJ, Zhang Z, Song F, Robert C, Marie X, Gao W, Tan PH, Zhang J. Quantum interference between dark-excitons and zone-edged acoustic phonons in few-layer WS 2. Nat Commun 2023; 14:88. [PMID: 36604415 PMCID: PMC9816112 DOI: 10.1038/s41467-022-35714-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 12/15/2022] [Indexed: 01/07/2023] Open
Abstract
Fano resonance which describes a quantum interference between continuum and discrete states, provides a unique method for studying strongly interacting physics. Here, we report a Fano resonance between dark excitons and zone-edged acoustic phonons in few-layer WS2 by using the resonant Raman technique. The discrete phonons with large momentum at the M-point of the Brillouin zone and the continuum dark exciton states related to the optically forbidden transition at K and Q valleys are coupled by the exciton-phonon interactions. We observe rich Fano resonance behaviors across layers and modes defined by an asymmetry-parameter q: including constructive interference with two mirrored asymmetry Fano peaks (weak coupling, q > 1 and q < - 1), and destructive interference with Fano dip (strong coupling, ∣q∣ < < 1). Our results provide new insight into the exciton-phonon quantum interference in two-dimensional semiconductors, where such interferences play a key role in their transport, optical, and thermodynamic properties.
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Affiliation(s)
- Qing-Hai Tan
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China ,grid.410726.60000 0004 1797 8419Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049 China ,grid.59025.3b0000 0001 2224 0361Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore, Singapore
| | - Yun-Mei Li
- grid.12955.3a0000 0001 2264 7233Department of Physics, Xiamen University, Xiamen, 361005 China
| | - Jia-Min Lai
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China ,grid.410726.60000 0004 1797 8419Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Yu-Jia Sun
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China ,grid.410726.60000 0004 1797 8419Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Zhe Zhang
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China ,grid.410726.60000 0004 1797 8419Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Feilong Song
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China ,grid.410726.60000 0004 1797 8419Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Cedric Robert
- grid.462768.90000 0004 0383 4043University of Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - Xavier Marie
- grid.462768.90000 0004 0383 4043University of Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse, France
| | - Weibo Gao
- grid.59025.3b0000 0001 2224 0361Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore, Singapore ,grid.59025.3b0000 0001 2224 0361The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, 637371 Singapore, Singapore ,grid.4280.e0000 0001 2180 6431Centre for Quantum Technologies, National University of Singapore, Singapore, 117543 Singapore
| | - Ping-Heng Tan
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China ,grid.410726.60000 0004 1797 8419Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Jun Zhang
- grid.9227.e0000000119573309State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 China ,grid.410726.60000 0004 1797 8419Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049 China ,grid.410726.60000 0004 1797 8419CAS Center of Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, 100049 China
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25
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Wang XQ. Properties of the Interaction Between Excitons and Surface Acoustic Phonons in Multilayer Graphene. IRANIAN JOURNAL OF SCIENCE AND TECHNOLOGY, TRANSACTIONS A: SCIENCE 2022. [DOI: 10.1007/s40995-022-01393-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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26
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Kumar J, Patbhaje U, Shrivastava M. Breathing Mode's Temperature Coefficient Estimation and Interlayer Phonon Scattering Model of Few-Layer Phosphorene. ACS OMEGA 2022; 7:43462-43467. [PMID: 36506203 PMCID: PMC9730771 DOI: 10.1021/acsomega.2c03759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 11/07/2022] [Indexed: 06/17/2023]
Abstract
The breathing mode's Raman characteristic is a key parameter that estimates the number of layers and helps to determine interlayer thermal coupling in multilayer phosphorene. However, its temperature coefficient is not investigated yet, probably due to phosphorene's ambient instability, difficulties in capturing its Raman modes, and relatively weak temperature sensitivity than the corresponding primary intralayer Raman modes. Here, we captured the breathing modes' Raman scattering in multiple phosphorene flakes at different temperatures and estimated the corresponding first-order temperature coefficient. The captured modes show a negative temperature coefficient of around -0.0025 cm-1/K. Besides, we have explored a unique feature of the breathing mode phonon scattering with temperature. The modes closely follow the dominant three-phonon process and four-phonon process scattering phenomena at low- and high-temperature ranges. The three-phonon process scattering is dominant below ∼100 K, shifting to the dominant four-phonon process scattering beyond ∼150 K. Moreover, the phonon modes show anomalous behavior of blue shift with temperature during 100-150 K, probably due to transition in the scattering process. Our study shows the significant dependency of the breathing modes over temperature, which helps to understand and model phosphorene's interlayer thermal and mechanical properties. The study also reflects that phosphorene has significant interlayer heat transport capability due to three- and four-phonon scattering features.
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27
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Wang PJ, Tsai PC, Yang ZS, Lin SY, Sun CK. Revealing the interlayer van der Waals coupling of bi-layer and tri-layer MoS 2 using terahertz coherent phonon spectroscopy. PHOTOACOUSTICS 2022; 28:100412. [PMID: 36281319 PMCID: PMC9587369 DOI: 10.1016/j.pacs.2022.100412] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/20/2022] [Accepted: 10/07/2022] [Indexed: 06/16/2023]
Abstract
In this research, we applied THz coherent phonon spectroscopy to optically probe the vibrational modes of the epitaxially-grown bi-layer and tri-layer MoS2 on sapphire substrate. The layers' THz vibration is displacively stimulated and temporally retrieved by near-UV femtosecond laser pulses, revealing Raman-active and Raman-inactive modes in one measurement. With the complete breathing modes revealed, here we extend the linear chain model by considering the elastic contact with the substrate and vdWs coupling of the next nearest MoS2 layer to analyze the effective spring constants. We further considered the intralayer stiffness as a correction term to acquire the actual interlayer vdWs coupling. Our THz phonon spectroscopy results indicate the interlayer spring constants of 9.03 × 1019 N/m3 and 9.86 × 1019 N/m3 for bi-layer and tri-layer respectively. The extended model further suggests that a non-negligible substrate mechanical coupling and next nearest neighbor vdWs coupling of 1.48 × 1019 N/m3 and 1.04 × 1019 N/m3 have to be considered.
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Affiliation(s)
- Peng-Jui Wang
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Po-Cheng Tsai
- Graduate Institute of Electronics Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Rd., Taipei 10617, Taiwan
- Research Center for Applied Sciences, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
| | - Zih-Sian Yang
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Shih-Yen Lin
- Graduate Institute of Electronics Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Rd., Taipei 10617, Taiwan
- Research Center for Applied Sciences, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
| | - Chi-Kuang Sun
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
- Research Center for Applied Sciences, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
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28
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Luo W, Oyedele AD, Mao N, Puretzky A, Xiao K, Liang L, Ling X. Excitation-Dependent Anisotropic Raman Response of Atomically Thin Pentagonal PdSe 2. ACS PHYSICAL CHEMISTRY AU 2022; 2:482-489. [PMID: 36465836 PMCID: PMC9706783 DOI: 10.1021/acsphyschemau.2c00007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 07/15/2022] [Accepted: 07/22/2022] [Indexed: 06/17/2023]
Abstract
The group-10 noble-metal dichalcogenides have recently emerged as a promising group of two-dimensional materials due to their unique crystal structures and fascinating physical properties. In this work, the resonance enhancement of the interlayer breathing mode (B1) and intralayer Ag 1 and Ag 3 modes in atomically thin pentagonal PdSe2 were studied using angle-resolved polarized Raman spectroscopy with 13 excitation wavelengths. Under the excitation energies of 2.33, 2.38, and 2.41 eV, the Raman intensities of both the low-frequency breathing mode B1 and high-frequency mode Ag 1 of all the thicknesses are the strongest when the incident polarization is parallel to the a axis of PdSe2, serving as a fast identification of the crystal orientation of few-layer PdSe2. We demonstrated that the intensities of B1, Ag 1, and Ag 3 modes are the strongest with the excitation energies between 2.18 and 2.38 eV when the incident polarization is parallel to PdSe2 a axis, which arises from the resonance enhancement caused by the absorption. Our investigation reveals the underlying interplay of the anisotropic electron-phonon and electron-photon interactions in the Raman scattering process of atomically thin PdSe2. It paves the way for future applications on PdSe2-based optoelectronics.
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Affiliation(s)
- Weijun Luo
- Department
of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| | - Akinola D. Oyedele
- Center
for Nanophase Materials Sciences, Oak Ridge
National Laboratory, Oak Ridge, Tennessee 37831, United States
- Bredesen
Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Nannan Mao
- Department
of Chemistry, Boston University, Boston, Massachusetts 02215, United States
- Department
of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Alexander Puretzky
- Center
for Nanophase Materials Sciences, Oak Ridge
National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Kai Xiao
- Center
for Nanophase Materials Sciences, Oak Ridge
National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Liangbo Liang
- Center
for Nanophase Materials Sciences, Oak Ridge
National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Xi Ling
- Department
of Chemistry, Boston University, Boston, Massachusetts 02215, United States
- Division
of Materials Science and Engineering, Boston
University, Boston, Massachusetts 02215, United States
- The Photonics
Center, Boston University, Boston, Massachusetts 02215, United States
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29
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ter Huurne SE, Da Cruz AR, van Hoof N, Godiksen RH, Elrafei SA, Curto AG, Flatté ME, Rivas JG. High-Frequency Sheet Conductance of Nanolayered WS 2 Crystals for Two-Dimensional Nanodevices. ACS APPLIED NANO MATERIALS 2022; 5:15557-15562. [PMID: 36338326 PMCID: PMC9623546 DOI: 10.1021/acsanm.2c03517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
Time-resolved terahertz (THz) spectroscopy is a powerful technique for the determination of charge transport properties in photoexcited semiconductors. However, the relatively long wavelengths of THz radiation and the diffraction limit imposed by optical imaging systems reduce the applicability of THz spectroscopy to large samples with dimensions in the millimeter to centimeter range. Exploiting THz near-field spectroscopy, we present the first time-resolved THz measurements on a single exfoliated 2D nanolayered crystal of a transition metal dichalcogenide (WS2). The high spatial resolution of THz near-field spectroscopy enables mapping of the sheet conductance for an increasing number of atomic layers. The single-crystalline structure of the nanolayered crystal allows for the direct observation of low-energy phonon modes, which are present in all thicknesses, coupling with free carriers. Density functional theory calculations show that the phonon mode corresponds to the breathing mode between atomic layers in the weakly bonded van der Waals layers, which can be strongly influenced by substrate-induced strain. The non-invasive and high-resolution mapping technique of carrier dynamics in nanolayered crystals by time-resolved THz time domain spectroscopy enables possibilities for the investigation of the relation between phonons and charge transport in nanoscale semiconductors for applications in two-dimensional nanodevices.
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Affiliation(s)
- Stan E.T. ter Huurne
- Department
of Applied Physics and Eindhoven Hendrik Casimir Institute, Eindhoven University of Technology, P.O. Box 513, Eindhoven5600 MB, The Netherlands
| | - Adonai Rodrigues Da Cruz
- Department
of Applied Physics and Eindhoven Hendrik Casimir Institute, Eindhoven University of Technology, P.O. Box 513, Eindhoven5600 MB, The Netherlands
| | - Niels van Hoof
- Department
of Applied Physics and Eindhoven Hendrik Casimir Institute, Eindhoven University of Technology, P.O. Box 513, Eindhoven5600 MB, The Netherlands
| | - Rasmus H. Godiksen
- Department
of Applied Physics and Eindhoven Hendrik Casimir Institute, Eindhoven University of Technology, P.O. Box 513, Eindhoven5600 MB, The Netherlands
| | - Sara A. Elrafei
- Department
of Applied Physics and Eindhoven Hendrik Casimir Institute, Eindhoven University of Technology, P.O. Box 513, Eindhoven5600 MB, The Netherlands
| | - Alberto G. Curto
- Department
of Applied Physics and Eindhoven Hendrik Casimir Institute, Eindhoven University of Technology, P.O. Box 513, Eindhoven5600 MB, The Netherlands
| | - Michael E. Flatté
- Department
of Applied Physics and Eindhoven Hendrik Casimir Institute, Eindhoven University of Technology, P.O. Box 513, Eindhoven5600 MB, The Netherlands
- Department
of Physics and Astronomy, University of
Iowa, Iowa City, Iowa52242, United States
| | - Jaime Gómez Rivas
- Department
of Applied Physics and Eindhoven Hendrik Casimir Institute, Eindhoven University of Technology, P.O. Box 513, Eindhoven5600 MB, The Netherlands
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30
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Ng RC, El Sachat A, Cespedes F, Poblet M, Madiot G, Jaramillo-Fernandez J, Florez O, Xiao P, Sledzinska M, Sotomayor-Torres CM, Chavez-Angel E. Excitation and detection of acoustic phonons in nanoscale systems. NANOSCALE 2022; 14:13428-13451. [PMID: 36082529 PMCID: PMC9520674 DOI: 10.1039/d2nr04100f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 08/15/2022] [Indexed: 06/15/2023]
Abstract
Phonons play a key role in the physical properties of materials, and have long been a topic of study in physics. While the effects of phonons had historically been considered to be a hindrance, modern research has shown that phonons can be exploited due to their ability to couple to other excitations and consequently affect the thermal, dielectric, and electronic properties of solid state systems, greatly motivating the engineering of phononic structures. Advances in nanofabrication have allowed for structuring and phonon confinement even down to the nanoscale, drastically changing material properties. Despite developments in fabricating such nanoscale devices, the proper manipulation and characterization of phonons continues to be challenging. However, a fundamental understanding of these processes could enable the realization of key applications in diverse fields such as topological phononics, information technologies, sensing, and quantum electrodynamics, especially when integrated with existing electronic and photonic devices. Here, we highlight seven of the available methods for the excitation and detection of acoustic phonons and vibrations in solid materials, as well as advantages, disadvantages, and additional considerations related to their application. We then provide perspectives towards open challenges in nanophononics and how the additional understanding granted by these techniques could serve to enable the next generation of phononic technological applications.
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Affiliation(s)
- Ryan C Ng
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain.
| | | | - Francisco Cespedes
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain.
- Departamento de Física, Universidad Autónoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
| | - Martin Poblet
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain.
| | - Guilhem Madiot
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain.
| | - Juliana Jaramillo-Fernandez
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain.
| | - Omar Florez
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain.
- Departamento de Física, Universidad Autónoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
| | - Peng Xiao
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain.
- Departamento de Física, Universidad Autónoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
| | - Marianna Sledzinska
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain.
| | - Clivia M Sotomayor-Torres
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain.
- ICREA, Passeig Lluis Companys 23, 08010 Barcelona, Spain
| | - Emigdio Chavez-Angel
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain.
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31
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Kiemle J, Powalla L, Polyudov K, Gulati L, Singh M, Holleitner AW, Burghard M, Kastl C. Gate-Tunable Helical Currents in Commensurate Topological Insulator/Graphene Heterostructures. ACS NANO 2022; 16:12338-12344. [PMID: 35968692 DOI: 10.1021/acsnano.2c03370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
van der Waals heterostructures made from graphene and three-dimensional topological insulators promise very high electron mobilities, a nontrivial spin texture, and a gate-tunability of electronic properties. Such a combination of advantageous electronic characteristics can only be achieved through proximity effects in heterostructures, as graphene lacks a large enough spin-orbit interaction. In turn, the heterostructures are promising candidates for all-electrical control of proximity-induced spin phenomena. Here, we explore epitaxially grown interfaces between graphene and the lattice-matched topological insulator Bi2Te2Se. For this heterostructure, spin-orbit coupling proximity has been predicted to impart an anisotropic and electronically tunable spin texture. Polarization-resolved second-harmonic generation, Raman spectroscopy, and time-resolved magneto-optic Kerr microscopy are combined to demonstrate that the atomic interfaces align in a commensurate symmetry with characteristic interlayer vibrations. By polarization-resolved photocurrent measurements, we find a circular photogalvanic effect which is drastically enhanced at the Dirac point of the proximitized graphene. We attribute the peculiar gate-tunability to the proximity-induced interfacial spin structure, which could be exploited for, e.g., spin filters.
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Affiliation(s)
- Jonas Kiemle
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- MCQST, Schellingstrasse 4, 80799 München, Germany
| | - Lukas Powalla
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Katharina Polyudov
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Lovish Gulati
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Maanwinder Singh
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- MCQST, Schellingstrasse 4, 80799 München, Germany
| | - Alexander W Holleitner
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- MCQST, Schellingstrasse 4, 80799 München, Germany
| | - Marko Burghard
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Christoph Kastl
- Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
- MCQST, Schellingstrasse 4, 80799 München, Germany
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32
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Rodriguez A, Krayev A, Velický M, Frank O, El-Khoury PZ. Nano-optical Visualization of Interlayer Interactions in WSe 2/WS 2 Heterostructures. J Phys Chem Lett 2022; 13:5854-5859. [PMID: 35727212 PMCID: PMC9335877 DOI: 10.1021/acs.jpclett.2c01250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The interplay between excitons and phonons governs the optical and electronic properties of transition metal dichalcogenides (TMDs). Even though a number of linear and nonlinear optical-, electron-, and photoelectron-based approaches have been developed and/or adopted to characterize excitons and phonons in single/few-layer TMDs and their heterostructures, no existing method is capable of directly probing ultralow-frequency and interlayer phonons on the nanoscale. To this end, we developed ultralow-frequency tip-enhanced Raman spectroscopy, which allows spectrally and spatially resolved chemical and structural nanoimaging of WSe2/WS2 heterostructures. In this work, we apply this method to analyze phonons in nanobubbles that are sustained in these heterobilayers. Our method is capable of directly probing interlayer (de)coupling using our novel structurally sensitive nano-optical probe and the interplay between excitons and interlayer/intralayer phonons through correlation analysis of the recorded spectral images.
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Affiliation(s)
- Alvaro Rodriguez
- J.
Heyrovský Institute of Physical Chemistry, Czech Academy of
Sciences, Dolejškova 2155/3, 182 23 Prague, Czech Republic
| | - Andrey Krayev
- Horiba
Instruments, Inc., 359 Bel Marin Keys Boulevard, Suite 18, Novato, California 94949, United States
| | - Matěj Velický
- J.
Heyrovský Institute of Physical Chemistry, Czech Academy of
Sciences, Dolejškova 2155/3, 182 23 Prague, Czech Republic
| | - Otakar Frank
- J.
Heyrovský Institute of Physical Chemistry, Czech Academy of
Sciences, Dolejškova 2155/3, 182 23 Prague, Czech Republic
| | - Patrick Z. El-Khoury
- Physical
Sciences Division, Pacific Northwest National
Laboratory, P.O. Box 999, Richland, Washington 99352, United States
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33
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Li G, Wu X, Gao Y, Ma X, Hou F, Cheng H, Huang Q, Wu YC, DeCapua MC, Zhang Y, Lin J, Liu C, Huang L, Zhao Y, Yan J, Huang M. Observation of Ultrastrong Coupling between Substrate and the Magnetic Topological Insulator MnBi 2Te 4. NANO LETTERS 2022; 22:3856-3864. [PMID: 35503660 DOI: 10.1021/acs.nanolett.1c04194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The intrinsic magnetic topological insulator MnBi2Te4 has attracted significant interest recently as a promising platform for exploring exotic quantum phenomena. Here we report that, when atomically thin MnBi2Te4 is deposited on a substrate such as silicon oxide or gold, there is a very strong mechanical coupling between the atomic layer and the supporting substrate. This is manifested as an intense low-frequency breathing Raman mode that is present even for monolayer MnBi2Te4. Interestingly, this coupling turns out to be stronger than the interlayer coupling between the MnBi2Te4 atomic layers. We further found that these low-energy breathing modes are highly sensitive to sample degradation, and they become drastically weaker upon ambient air exposure. This is in contrast to the higher energy optical phonon modes which are much more robust, suggesting that the low-energy Raman modes found here can be an effective indicator of sample quality.
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Affiliation(s)
- Gaomin Li
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People's Republic of China
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Xiaohua Wu
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People's Republic of China
| | - Yifan Gao
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People's Republic of China
| | - Xiaoming Ma
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, People's Republic of China
| | - Fuchen Hou
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People's Republic of China
| | - Hanyan Cheng
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People's Republic of China
| | - Qiaoling Huang
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People's Republic of China
| | - Yueh-Chun Wu
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Matthew C DeCapua
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Yujun Zhang
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People's Republic of China
| | - Junhao Lin
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People's Republic of China
| | - Chang Liu
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People's Republic of China
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, People's Republic of China
| | - Li Huang
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People's Republic of China
| | - Yue Zhao
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People's Republic of China
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, People's Republic of China
| | - Jun Yan
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Mingyuan Huang
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People's Republic of China
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34
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He W, Wetherington MT, Ulman KA, Gray JL, Robinson JA, Quek SY. Shear Modes in a 2D Polar Metal. J Phys Chem Lett 2022; 13:4015-4020. [PMID: 35485838 DOI: 10.1021/acs.jpclett.2c00719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Low-frequency shear and breathing modes are important Raman signatures of two-dimensional (2D) materials, providing information on the number of layers and insights into interlayer interactions. We elucidate the nature of low-frequency modes in a 2D polar metal-2D Ga covalently bonded to a SiC substrate, using a first-principles Green's function-based approach. The low-frequency Raman modes are dominated by surface resonance modes, consisting primarily of out-of-phase shear modes in Ga, coupled to SiC phonons. Breathing modes are strongly coupled to the substrate and do not give rise to peaks in the phonon spectra. The highest-frequency shear mode blue-shifts significantly with increasing thickness, reflecting both an increase in the number of Ga layers and an increase in the effective interlayer force constant. The surface resonance modes evolve into localized 2D Ga modes as the phonon momentum increases. The predicted low-frequency modes are consistent with Raman measurements on 2D polar Ga.
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Affiliation(s)
- Wen He
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive, Singapore 117575
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, Singapore 117546
| | - Maxwell T Wetherington
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Kanchan Ajit Ulman
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, Singapore 117546
| | - Jennifer L Gray
- Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Joshua A Robinson
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- 2-Dimensional Crystal Consortium, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Su Ying Quek
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive, Singapore 117575
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, Singapore 117546
- Department of Physics, National University of Singapore, Singapore 117551
- NUS Graduate School Integrative Sciences and Engineering Programme, National University of Singapore, Singapore 117456
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35
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Radatović B, Jadriško V, Kamal S, Kralj M, Novko D, Vujičić N, Petrović M. Macroscopic Single-Phase Monolayer Borophene on Arbitrary Substrates. ACS APPLIED MATERIALS & INTERFACES 2022; 14:21727-21737. [PMID: 35500044 DOI: 10.1021/acsami.2c03678] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A major challenge in the investigation of all 2D materials is the development of synthesis protocols and tools which would enable their large-scale production and effective manipulation. The same holds for borophene, where experiments are still largely limited to in situ characterizations of small-area samples. In contrast, our work is based on millimeter-sized borophene sheets, synthesized on an Ir(111) surface in ultrahigh vacuum. Besides high-quality macroscopic synthesis, as confirmed by low-energy electron diffraction (LEED) and atomic force microscopy (AFM), we also demonstrate a successful transfer of borophene from Ir to a Si wafer via electrochemical delamination process. Comparative Raman spectroscopy, in combination with the density functional theory (DFT) calculations, proved that borophene's crystal structure has been preserved in the transfer. Our results demonstrate successful growth and manipulation of large-scale, single-layer borophene sheets with minor defects and ambient stability, thus expediting borophene implementation into more complex systems and devices.
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Affiliation(s)
- Borna Radatović
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička 46, 10000 Zagreb, Croatia
| | - Valentino Jadriško
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička 46, 10000 Zagreb, Croatia
| | - Sherif Kamal
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička 46, 10000 Zagreb, Croatia
| | - Marko Kralj
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička 46, 10000 Zagreb, Croatia
| | - Dino Novko
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička 46, 10000 Zagreb, Croatia
| | - Nataša Vujičić
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička 46, 10000 Zagreb, Croatia
| | - Marin Petrović
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička 46, 10000 Zagreb, Croatia
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36
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Abstract
The two-dimensional layered semiconductor InSe, with its high carrier mobility, chemical stability, and strong charge transfer ability, plays a crucial role in optoelectronic devices. The number of InSe layers (L) has an important influence on its band structure and optoelectronic properties. Herein we present systematic investigations on few-layer (1L-7L) γ-InSe by optical contrast and Raman spectroscopy. We propose three quantified formulas to quickly identify the layer number using optical contrast, the frequency difference of two A1 modes, and ultralow-frequency Raman spectroscopy, respectively. Moreover, angle-resolved polarization Raman spectra show that γ-InSe is isotropic in the a-b plane. Furthermore, using Raman mapping, we find that the relative strength of the low-frequency interlayer shear modes is particularly sensitive to the interaction between the sample and the substrate.
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Affiliation(s)
- Yu-Jia Sun
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Si-Min Pang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jun Zhang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
- CAS Center of Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100049, China
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37
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Yang MM, Leng YC, Liu YL, Liu Y, Zhao YN, Tan L, Hu XW, Lian RQ, Liu XL, Cong RD, Sun SS, Li XL. Phonon and Exciton Properties between WS 2 and MoS 2 Layers via Inversion Heterostructure Engineering. ACS APPLIED MATERIALS & INTERFACES 2022; 14:19012-19022. [PMID: 35421305 DOI: 10.1021/acsami.1c24368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Recently, two-dimensional (2D) van der Waals heterostructures (vdWHs) have exhibited emergent electronic and optical properties due to their peculiar phonons and excitons, which lay the foundation for the development of photoelectronic devices. The dielectric environment plays an important role in the interlayer coupling of vdWHs. Here, we studied the interlayer and extra-layer dielectric effects on phonon and exciton properties in WS2/MoS2 and MoS2/WS2 vdWHs by Raman and photoluminescence (PL) spectroscopy. The ultralow frequency (ULF) Raman modes are insensitive to atomic arrangement at the interface between 1LW and 1LM and dielectric environments of neighboring materials, and the layer breathing mode (LBM) frequency follows that of WS2. The shift of high-frequency (HF) Raman modes is attributable to interlayer dielectric screening and charge transfer effects. Furthermore, the energy of interlayer coupling exciton peak I is insensitive to atomic arrangement at the interface between 1LW and 1LM and its energy follows that of MoS2, but the slight intensity difference in inversion vdWHs means that the substrate's dielectric properties may induce doping on the bottom layer. This paper provides fundamental understanding of phonon and exciton properties of such artificially formed vdWHs structures, which is important for new insights into manipulating the performances of potential devices.
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Affiliation(s)
- Ming-Ming Yang
- National and Local Joint Engineering Laboratory of New Energy Photoelectric Devices, College of Physics Science & Technology, Hebei University, Baoding 071002, P. R. China
| | - Yu-Chen Leng
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P. R. China
- Center of Materials Science and Optoelectronics Engineering & CAS Center of Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yan-Liang Liu
- National and Local Joint Engineering Laboratory of New Energy Photoelectric Devices, College of Physics Science & Technology, Hebei University, Baoding 071002, P. R. China
| | - Yi Liu
- National and Local Joint Engineering Laboratory of New Energy Photoelectric Devices, College of Physics Science & Technology, Hebei University, Baoding 071002, P. R. China
| | - Ya-Nan Zhao
- National and Local Joint Engineering Laboratory of New Energy Photoelectric Devices, College of Physics Science & Technology, Hebei University, Baoding 071002, P. R. China
| | - Li Tan
- National and Local Joint Engineering Laboratory of New Energy Photoelectric Devices, College of Physics Science & Technology, Hebei University, Baoding 071002, P. R. China
| | - Xiao-Wen Hu
- National and Local Joint Engineering Laboratory of New Energy Photoelectric Devices, College of Physics Science & Technology, Hebei University, Baoding 071002, P. R. China
| | - Ru-Qian Lian
- National and Local Joint Engineering Laboratory of New Energy Photoelectric Devices, College of Physics Science & Technology, Hebei University, Baoding 071002, P. R. China
| | - Xue-Lu Liu
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P. R. China
| | - Ri-Dong Cong
- National and Local Joint Engineering Laboratory of New Energy Photoelectric Devices, College of Physics Science & Technology, Hebei University, Baoding 071002, P. R. China
| | - Shi-Shuai Sun
- College of Science, Tianjin University of Technology, Tianjin 300384, P. R. China
| | - Xiao-Li Li
- National and Local Joint Engineering Laboratory of New Energy Photoelectric Devices, College of Physics Science & Technology, Hebei University, Baoding 071002, P. R. China
- State Key Laboratory of Photovoltaic Materials & Technology, Yingli Solar, Baoding 071051, P. R. China
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38
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Shin KH, Seo MK, Pak S, Jang AR, Sohn JI. Observation of Strong Interlayer Couplings in WS 2/MoS 2 Heterostructures via Low-Frequency Raman Spectroscopy. NANOMATERIALS 2022; 12:nano12091393. [PMID: 35564101 PMCID: PMC9101887 DOI: 10.3390/nano12091393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/14/2022] [Accepted: 04/16/2022] [Indexed: 11/16/2022]
Abstract
Van der Waals (vdW) heterostructures based on two-dimensional (2D) transition metal dichalcogenides (TMDCs), particularly WS2/MoS2 heterostructures with type-II band alignments, are considered as ideal candidates for future functional optoelectronic applications owing to their efficient exciton dissociation and fast charge transfers. These physical properties of vdW heterostructures are mainly influenced by the interlayer coupling occurring at the interface. However, a comprehensive understanding of the interlayer coupling in vdW heterostructures is still lacking. Here, we present a detailed analysis of the low-frequency (LF) Raman modes, which are sensitive to interlayer coupling, in bilayers of MoS2, WS2, and WS2/MoS2 heterostructures directly grown using chemical vapor deposition to avoid undesirable interfacial contamination and stacking mismatch effects between the monolayers. We clearly observe two distinguishable LF Raman modes, the interlayer in-plane shear and out-of-plane layer-breathing modes, which are dependent on the twisting angles and interface quality between the monolayers, in all the 2D bilayered structures, including the vdW heterostructure. In contrast, LF modes are not observed in the MoS2 and WS2 monolayers. These results indicate that our directly grown 2D bilayered TMDCs with a favorable stacking configuration and high-quality interface can induce strong interlayer couplings, leading to LF Raman modes.
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Affiliation(s)
- Ki Hoon Shin
- Division of Physics and Semiconductor Science, Dongguk University, Seoul 04620, Korea; (K.H.S.); (M.-K.S.)
| | - Min-Kyu Seo
- Division of Physics and Semiconductor Science, Dongguk University, Seoul 04620, Korea; (K.H.S.); (M.-K.S.)
| | - Sangyeon Pak
- School of Electronic and Electrical Engineering, Hongik University, Seoul 04066, Korea;
| | - A-Rang Jang
- Department of Electrical Engineering, Semyung University, Jecheon 27136, Korea
- Correspondence: (A.-R.J.); (J.I.S.)
| | - Jung Inn Sohn
- Division of Physics and Semiconductor Science, Dongguk University, Seoul 04620, Korea; (K.H.S.); (M.-K.S.)
- Correspondence: (A.-R.J.); (J.I.S.)
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39
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Singh K, Garg D, Bandyopadhyay A, Sengupta A. Dual spectroscopic detection of THz energy modes of critical chemical compounds. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 271:120923. [PMID: 35121475 DOI: 10.1016/j.saa.2022.120923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 01/14/2022] [Accepted: 01/17/2022] [Indexed: 06/14/2023]
Abstract
Precise identification and sensing of organic and inorganic molecular systems are key factors in several applications in present industrial and scientific domains. While high energy modes, due to electronic interactions, are mostly impervious to the initial thermodynamic or chemical conditions, the low energy modes are sensitive to such alterations which makes them suitable for quality control purpose with sensitive spectral identification methods. Here we report for the first time, several low frequency peaks of specific nitrogen-based compounds and their derivatives, using the dual spectroscopic approach of Terahertz Time-Domain Spectroscopy (THz-TDS) and THz Raman Spectroscopy (THz-RS). Two different isomeric molecular systems have also been investigated to assess both the selectivity and specificity of low energy modes in their identification and spectral correlation in terms of molecular interactions. This information of low frequency modes can be utilized readily by pharmaceutical and agri-food industries, chemical engineering and crystal growth communities in identification, detection, quality control and industrial waste management.
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Affiliation(s)
- Khushboo Singh
- Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Diksha Garg
- Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Aparajita Bandyopadhyay
- Joint Advanced Technology Center - Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Amartya Sengupta
- Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India; School of IT and Electrical Engineering, University of Queensland, Brisbane, QLD 4072, Australia.
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40
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Itoh N, Hanari N. Reliable estimation of Raman shifts for peaks of l-cystine (NMIJ CRM 6025-a) in the low-frequency region. ANAL SCI 2022; 38:657-664. [DOI: 10.1007/s44211-022-00080-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 01/06/2022] [Indexed: 11/28/2022]
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41
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Ko W, Gai Z, Puretzky AA, Liang L, Berlijn T, Hachtel JA, Xiao K, Ganesh P, Yoon M, Li AP. Understanding Heterogeneities in Quantum Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022:e2106909. [PMID: 35170112 DOI: 10.1002/adma.202106909] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 02/08/2022] [Indexed: 06/14/2023]
Abstract
Quantum materials are usually heterogeneous, with structural defects, impurities, surfaces, edges, interfaces, and disorder. These heterogeneities are sometimes viewed as liabilities within conventional systems; however, their electronic and magnetic structures often define and affect the quantum phenomena such as coherence, interaction, entanglement, and topological effects in the host system. Therefore, a critical need is to understand the roles of heterogeneities in order to endow materials with new quantum functions for energy and quantum information science applications. In this article, several representative examples are reviewed on the recent progress in connecting the heterogeneities to the quantum behaviors of real materials. Specifically, three intertwined topic areas are assessed: i) Reveal the structural, electronic, magnetic, vibrational, and optical degrees of freedom of heterogeneities. ii) Understand the effect of heterogeneities on the behaviors of quantum states in host material systems. iii) Control heterogeneities for new quantum functions. This progress is achieved by establishing the atomistic-level structure-property relationships associated with heterogeneities in quantum materials. The understanding of the interactions between electronic, magnetic, photonic, and vibrational states of heterogeneities enables the design of new quantum materials, including topological matter and quantum light emitters based on heterogenous 2D materials.
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Affiliation(s)
- Wonhee Ko
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Zheng Gai
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Alexander A Puretzky
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Liangbo Liang
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Tom Berlijn
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Jordan A Hachtel
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Kai Xiao
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Panchapakesan Ganesh
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Mina Yoon
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - An-Ping Li
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
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42
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Konar R, Rajeswaran B, Paul A, Teblum E, Aviv H, Perelshtein I, Grinberg I, Tischler YR, Nessim GD. CVD-Assisted Synthesis of 2D Layered MoSe 2 on Mo Foil and Low Frequency Raman Scattering of Its Exfoliated Few-Layer Nanosheets on CaF 2 Substrates. ACS OMEGA 2022; 7:4121-4134. [PMID: 35155906 PMCID: PMC8829917 DOI: 10.1021/acsomega.1c05652] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 01/04/2022] [Indexed: 06/14/2023]
Abstract
Transition-metal dichalcogenides (TMDCs) are unique layered materials with exotic properties. So, examining their structures holds tremendous importance. 2H-MoSe2 (analogous to MoS2; Gr. 6 TMDC) is a crucial optoelectronic material studied extensively using Raman spectroscopy. In this regard, low-frequency Raman (LFR) spectroscopy can probe this material's structure as it reveals distinct vibration modes. Here, we focus on understanding the microstructural evolution of different 2H-MoSe2 morphologies and their layers using LFR scattering. We grew phase-pure 2H-MoSe2 (with variable microstructures) directly on a Mo foil using a two-furnace ambient-pressure chemical vapor deposition (CVD) system by carefully controlling the process parameters. We analyzed the layers of exfoliated flakes after ultrasonication and drop-cast 2H-MoSe2 of different layer thicknesses by choosing different concentrations of 2H-MoSe2 solutions. Further detailed analyses of the respective LFR regions confirm the presence of newly identified Raman signals for the 2H-MoSe2 nanosheets drop-cast on Raman-grade CaF2. Our results show that CaF2 is an appropriate Raman-enhancing substrate compared to Si/SiO2 as it presents new LFR modes of 2H-MoSe2. Therefore, CaF2 substrates are a promising medium to characterize in detail other TMDCs using LFR spectroscopy.
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43
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Yagmurcukardes M, Sozen Y, Baskurt M, Peeters FM, Sahin H. Interface-dependent phononic and optical properties of GeO/MoSO heterostructures. NANOSCALE 2022; 14:865-874. [PMID: 34985489 DOI: 10.1039/d1nr06534c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The interface-dependent electronic, vibrational, piezoelectric, and optical properties of van der Waals heterobilayers, formed by buckled GeO (b-GeO) and Janus MoSO structures, are investigated by means of first-principles calculations. The electronic band dispersions show that O/Ge and S/O interface formations result in a type-II band alignment with direct and indirect band gaps, respectively. In contrast, O/O and S/Ge interfaces give rise to the formation of a type-I band alignment with an indirect band gap. By considering the Bethe-Salpeter equation (BSE) on top of G0W0 approximation, it is shown that different interfaces can be distinguished from each other by means of the optical absorption spectra as a consequence of the band alignments. Additionally, the low- and high-frequency regimes of the Raman spectra are also different for each interface type. The alignment of the individual dipoles, which is interface-dependent, either weakens or strengthens the net dipole of the heterobilayers and results in tunable piezoelectric coefficients. The results indicate that the possible heterobilayers of b-GeO/MoSO asymmetric structures possess various electronic, optical, and piezoelectric properties arising from the different interface formations and can be distinguished by means of various spectroscopic techniques.
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Affiliation(s)
- M Yagmurcukardes
- Department of Photonics, Izmir Institute of Technology, 35430, Izmir, Turkey.
- Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
- NANOlab Center of Excellence, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Y Sozen
- Department of Photonics, Izmir Institute of Technology, 35430, Izmir, Turkey.
| | - M Baskurt
- Department of Photonics, Izmir Institute of Technology, 35430, Izmir, Turkey.
| | - F M Peeters
- Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
- NANOlab Center of Excellence, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - H Sahin
- Department of Photonics, Izmir Institute of Technology, 35430, Izmir, Turkey.
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44
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Park TG, Na HR, Chun SH, Cho WB, Lee S, Rotermund F. Coherent control of interlayer vibrations in Bi 2Se 3 van der Waals thin-films. NANOSCALE 2021; 13:19264-19273. [PMID: 34787629 DOI: 10.1039/d1nr05075c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Interlayer vibrations with discrete quantized modes in two-dimensional (2D) materials can be excited by ultrafast light due to the inherent low dimensionality and van der Waals force as a restoring force. Controlling such interlayer vibrations in layered materials, which are closely related to fundamental nanomechanical interactions and thermal transport, in spatial- and time-domain provides an in-depth understanding of condensed matters and potential applications for advanced phononic and photonics devices. The manipulation of interlayer vibrational modes has been implemented in a spatial domain through material design to develop novel optoelectronic and phononic devices with various 2D materials, but such control in a time domain is still lacking. We present an all-optical method for controlling the interlayer vibrations in a highly precise manner with Bi2Se3 as a promising optoelectronic and thermoelasticity material in layered structures using a coherently controlled pump and probe scheme. The observed thickness-dependent fast interlayer breathing modes and substrate-induced slow interfacial modes can be exactly explained by a modified linear chain model including coupling effect with substrate. In addition, the results of coherent control experiments also agree with the simulation results based on the interference of interlayer vibrations. This investigation is universally applicable for diverse 2D materials and provides insight into the interlayer vibration-related dynamics and novel device implementation based on an ultrafast timescale interlayer-spacing modulation scheme.
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Affiliation(s)
- Tae Gwan Park
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
| | - Hong Ryeol Na
- Department of Physics and Astronomy, Sejong University, Seoul 05006, Korea.
| | - Seung-Hyun Chun
- Department of Physics and Astronomy, Sejong University, Seoul 05006, Korea.
| | - Won Bae Cho
- Welfare & Medical ICT Research Department, Electronics and Telecommunications Research Institute (ETRI), Daejeon 34129, Korea
| | - Sunghun Lee
- Department of Physics and Astronomy, Sejong University, Seoul 05006, Korea.
| | - Fabian Rotermund
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
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45
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The helicity of Raman scattered light: principles and applications in two-dimensional materials. Sci China Chem 2021. [DOI: 10.1007/s11426-021-1119-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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46
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Pizzi G, Milana S, Ferrari AC, Marzari N, Gibertini M. Shear and Breathing Modes of Layered Materials. ACS NANO 2021; 15:12509-12534. [PMID: 34370440 PMCID: PMC8397437 DOI: 10.1021/acsnano.0c10672] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 06/14/2021] [Indexed: 05/19/2023]
Abstract
Layered materials (LMs), such as graphite, hexagonal boron nitride, and transition-metal dichalcogenides, are at the center of an ever-increasing research effort, due to their scientific and technological relevance. Raman and infrared spectroscopies are accurate, non-destructive approaches to determine a wide range of properties, including the number of layers, N, and the strength of the interlayer interactions. We present a general approach to predict the complete spectroscopic fan diagrams, i.e., the relations between frequencies and N for the optically active shear and layer-breathing modes of any multilayer comprising N ≥ 2 identical layers. In order to achieve this, we combine a description of the normal modes in terms of a one-dimensional mechanical model, with symmetry arguments that describe the evolution of the point group as a function of N. Group theory is then used to identify which modes are Raman- and/or infrared-active, and to provide diagrams of the optically active modes for any stack composed of identical layers. We implement the method and algorithms in an open-source tool to assist researchers in the prediction and interpretation of such diagrams. Our work will underpin future efforts on Raman and infrared characterization of known, and yet not investigated, LMs.
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Affiliation(s)
- Giovanni Pizzi
- Theory
and Simulation of Materials (THEOS), and National Centre for Computational
Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- E-mail:
| | - Silvia Milana
- Cambridge
Graphene Centre, University of Cambridge, Cambridge CB3 OFA, U.K.
| | - Andrea C. Ferrari
- Cambridge
Graphene Centre, University of Cambridge, Cambridge CB3 OFA, U.K.
- E-mail:
| | - Nicola Marzari
- Theory
and Simulation of Materials (THEOS), and National Centre for Computational
Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Marco Gibertini
- Theory
and Simulation of Materials (THEOS), and National Centre for Computational
Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- Dipartimento
di Scienze Fisiche, Informatiche e Matematiche, University of Modena and Reggio Emilia, IT-41125 Modena, Italy
- Department
of Quantum Matter Physics, University of
Geneva, CH-1211 Genéve, Switzerland
- E-mail:
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47
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Debnath R, Sett S, Biswas R, Raghunathan V, Ghosh A. A simple fabrication strategy for orientationally accurate twisted heterostructures. NANOTECHNOLOGY 2021; 32:455705. [PMID: 34298522 DOI: 10.1088/1361-6528/ac1756] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 07/23/2021] [Indexed: 06/13/2023]
Abstract
Van der Waals (vdW) heterostructure is a type of metamaterial where multiple layers of 2D materials are vertically aligned at controlled misorientation. The relative rotation in between the adjacent layers, or the twist angle between them plays a crucial role in changing the electronic band structure of the superlattice. The assembly of multi-layers of precisely twisted two dimensional layered materials requires knowledge of the atomic structure at the edge of the flake. It may be artificially created by the 'tear and stack' process. Otherwise, the crystallographic orientation needs to be determined through invasive processes such as transmission electron microscopy or scanning tunneling microscopy, and via second-harmonic generation (SHG). Here, we demonstrate a simple and elegant transfer protocol using only an optical microscope as a edge identifier tool through which, controlled transfer of twisted homobilayer and heterobilayer transition metal dichalcogenides is performed with close to 100% yield. The fabricated twisted vdW heterostructures have been characterized by SHG, Raman spectroscopy and photoluminiscence spectroscopy, confirming the desired twist angle within ∼0.5° accuracy. The presented method is reliable, quick and prevents the use of invasive tools which is desirable for reproducible device functionalities.
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Affiliation(s)
- Rahul Debnath
- Department of Physics, Indian Institute of Science, Bangalore 560012, India
| | - Shaili Sett
- Department of Physics, Indian Institute of Science, Bangalore 560012, India
| | - Rabindra Biswas
- Department of Electrical and Communication Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Varun Raghunathan
- Department of Electrical and Communication Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Arindam Ghosh
- Department of Physics, Indian Institute of Science, Bangalore 560012, India
- Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore 560012, India
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48
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Lin KQ, Holler J, Bauer JM, Parzefall P, Scheuck M, Peng B, Korn T, Bange S, Lupton JM, Schüller C. Large-Scale Mapping of Moiré Superlattices by Hyperspectral Raman Imaging. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2008333. [PMID: 34242447 DOI: 10.1002/adma.202008333] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 05/03/2021] [Indexed: 05/25/2023]
Abstract
Moiré superlattices can induce correlated-electronic phases in twisted van der Waals materials: strongly correlated quantum phenomena emerge, such as superconductivity and the Mott-insulating state. However, moiré superlattices produced through artificial stacking can be quite inhomogeneous, which hampers the development of a clear correlation between the moiré period and the emerging electrical and optical properties. Here, it is demonstrated in twisted-bilayer transition-metal dichalcogenides that low-frequency Raman scattering can be utilized not only to detect atomic reconstruction, but also to map out the inhomogeneity of the moiré lattice over large areas. The method is established based on the finding that both the interlayer-breathing mode and moiré phonons are highly susceptible to the moiré period and provide characteristic fingerprints. Hyperspectral Raman imaging visualizes microscopic domains of a 5° twisted-bilayer sample with an effective twist-angle resolution of about 0.1°. This ambient methodology can be conveniently implemented to characterize and preselect high-quality areas of samples for subsequent device fabrication, and for transport and optical experiments.
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Affiliation(s)
- Kai-Qiang Lin
- Department of Physics, University of Regensburg, 93053, Regensburg, Germany
| | - Johannes Holler
- Department of Physics, University of Regensburg, 93053, Regensburg, Germany
| | - Jonas M Bauer
- Department of Physics, University of Regensburg, 93053, Regensburg, Germany
| | - Philipp Parzefall
- Department of Physics, University of Regensburg, 93053, Regensburg, Germany
| | - Marten Scheuck
- Department of Physics, University of Regensburg, 93053, Regensburg, Germany
| | - Bo Peng
- TCM Group, Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK
| | - Tobias Korn
- Institute of Physics, University of Rostock, 18059, Rostock, Germany
| | - Sebastian Bange
- Department of Physics, University of Regensburg, 93053, Regensburg, Germany
| | - John M Lupton
- Department of Physics, University of Regensburg, 93053, Regensburg, Germany
| | - Christian Schüller
- Department of Physics, University of Regensburg, 93053, Regensburg, Germany
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49
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Tan Q, Rasmita A, Li S, Liu S, Huang Z, Xiong Q, Yang SA, Novoselov KS, Gao WB. Layer-engineered interlayer excitons. SCIENCE ADVANCES 2021; 7:7/30/eabh0863. [PMID: 34301603 PMCID: PMC8302131 DOI: 10.1126/sciadv.abh0863] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 06/07/2021] [Indexed: 05/21/2023]
Abstract
Photoluminescence (PL) from excitons serves as a powerful tool to characterize the optoelectronic property and band structure of semiconductors, especially for atomically thin two-dimensional transition metal dichalcogenide (TMD) materials. However, PL quenches quickly when the thickness of TMD materials increases from monolayer to a few layers, due to the change from direct to indirect band transition. Here, we show that PL can be recovered by engineering multilayer heterostructures, with the band transition reserved to be a direct type. We report emission from layer-engineered interlayer excitons from these multilayer heterostructures. Moreover, as desired for valleytronics devices, the lifetime, valley polarization, and valley lifetime of the generated interlayer excitons can all be substantially improved as compared with that in the monolayer-monolayer heterostructure. Our results pave the way for controlling the properties of interlayer excitons by layer engineering.
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Affiliation(s)
- Qinghai Tan
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Abdullah Rasmita
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Si Li
- Research Laboratory for Quantum Materials in Singapore University of Technology and Design, Singapore 487372, Singapore
- School of Physics, Northwest University, Xi' an 710069, China
| | - Sheng Liu
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Zumeng Huang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Qihua Xiong
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
| | - Shengyuan A Yang
- Research Laboratory for Quantum Materials in Singapore University of Technology and Design, Singapore 487372, Singapore.
| | - K S Novoselov
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Singapore.
| | - Wei-Bo Gao
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
- The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637371, Singapore
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50
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Mao N, Lin Y, Bie YQ, Palacios T, Liang L, Saito R, Ling X, Kong J, Tisdale WA. Resonance-Enhanced Excitation of Interlayer Vibrations in Atomically Thin Black Phosphorus. NANO LETTERS 2021; 21:4809-4815. [PMID: 34048260 DOI: 10.1021/acs.nanolett.1c00917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The strength of interlayer coupling critically affects the physical properties of 2D materials such as black phosphorus (BP), where the electronic structure depends sensitively on layer thickness. Rigid-layer vibrations reflect directly the interlayer coupling strength in 2D van der Waals solids, but measurement of these characteristic frequencies is made difficult by sample instability and small Raman scattering cross sections in atomically thin elemental crystals. Here, we overcome these challenges in BP by performing resonance-enhanced low-frequency Raman scattering under an argon-protective environment. Interlayer breathing modes for atomically thin BP were previously unobservable under conventional (nonresonant) excitation but became strongly enhanced when the excitation energy matched the sub-band electronic transitions of few-layer BP, down to bilayer thicknesses. The measured out-of-plane interlayer force constant was found to be 10.1 × 1019 N/m3 in BP, which is comparable to graphene. Accurate characterization of the interlayer coupling strength lays the foundation for future exploration of BP twisted structures and heterostructures.
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Affiliation(s)
- Nannan Mao
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Chemistry and Division of Materials Science and Engineering, Boston University, Boston, Massachusetts 02215, United States
| | - Yuxuan Lin
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Ya-Qing Bie
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Tomás Palacios
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Liangbo Liang
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Riichiro Saito
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - Xi Ling
- Department of Chemistry and Division of Materials Science and Engineering, Boston University, Boston, Massachusetts 02215, United States
- The Photonics Center, Boston University, Boston, Massachusetts 02215, United States
| | - Jing Kong
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - William A Tisdale
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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