1
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Zou J, Zhu R, Wang J, Meng H, Wang Z, Chen H, Weng YX. Coherent Phonon-Mediated Many-Body Interaction in Monolayer WSe 2. J Phys Chem Lett 2023; 14:4657-4665. [PMID: 37167104 DOI: 10.1021/acs.jpclett.3c00870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Due to the strong Coulomb interaction, the optical and electrical properties of two-dimensional transition metal dichalcogenides (TMDCs) are greatly determined by the emergence of many-body complexes such as excitons or trions. To fully realize the potential functionalities of these atomically thin materials, a comprehensive understanding of their many-body interaction mechanism is essential. Here, using the advanced femtosecond two-dimensional electronic spectroscopy technique combined with broadband transient absorption spectroscopy, a strong electron-exciton coupling effect in monolayer WSe2 following the ultrafast photoexcitation is revealed. We demonstrate that such many-body complexes can be generated effectively through the band-edge optical excitation, with a ∼1.5 ps stabilization process. The coherent optical phonon plays a dominant role in this electron-exciton interaction, and the coherence of the electron (exciton)-phonon coupling can last for ∼4.5 ps. This finding offers new insight into the formation mechanism of photoinduced many-body complexes in TMDCs.
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Affiliation(s)
- Jiading Zou
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ruidan Zhu
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jiayu Wang
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hanting Meng
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhuan Wang
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Hailong Chen
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Yu-Xiang Weng
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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2
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Qian C, Villafañe V, Petrić MM, Soubelet P, Stier AV, Finley JJ. Coupling of MoS_{2} Excitons with Lattice Phonons and Cavity Vibrational Phonons in Hybrid Nanobeam Cavities. PHYSICAL REVIEW LETTERS 2023; 130:126901. [PMID: 37027879 DOI: 10.1103/physrevlett.130.126901] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 01/23/2023] [Accepted: 02/28/2023] [Indexed: 06/19/2023]
Abstract
We report resonant Raman spectroscopy of neutral excitons X^{0} and intravalley trions X^{-} in hBN-encapsulated MoS_{2} monolayer embedded in a nanobeam cavity. By temperature tuning the detuning between Raman modes of MoS_{2} lattice phonons and X^{0}/X^{-} emission peaks, we probe the mutual coupling of excitons, lattice phonons and cavity vibrational phonons. We observe an enhancement of X^{0}-induced Raman scattering and a suppression for X^{-}-induced, and explain our findings as arising from the tripartite exciton-phonon-phonon coupling. The cavity vibrational phonons provide intermediate replica states of X^{0} for resonance conditions in the scattering of lattice phonons, thus enhancing the Raman intensity. In contrast, the tripartite coupling involving X^{-} is found to be much weaker, an observation explained by the geometry-dependent polarity of the electron and hole deformation potentials. Our results indicate that phononic hybridization between lattice and nanomechanical modes plays a key role in the excitonic photophysics and light-matter interaction in 2D-material nanophotonic systems.
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Affiliation(s)
- Chenjiang Qian
- Walter Schottky Institut and Physik Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany
| | - Viviana Villafañe
- Walter Schottky Institut and Physik Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany
| | - Marko M Petrić
- Walter Schottky Institut and Department of Electrical and Computer Engineering, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany
| | - Pedro Soubelet
- Walter Schottky Institut and Physik Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany
| | - Andreas V Stier
- Walter Schottky Institut and Physik Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany
| | - Jonathan J Finley
- Walter Schottky Institut and Physik Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany
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3
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Kim B, Luo Y, Rhodes D, Bai Y, Wang J, Liu S, Jordan A, Huang B, Li Z, Taniguchi T, Watanabe K, Owen J, Strauf S, Barmak K, Zhu X, Hone J. Free Trions with Near-Unity Quantum Yield in Monolayer MoSe 2. ACS NANO 2022; 16:140-147. [PMID: 34935357 DOI: 10.1021/acsnano.1c04331] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Trions, quasiparticles composed of an electron-hole pair bound to a second electron and/or hole, are many-body states with potential applications in optoelectronics. Trions in monolayer transition metal dichalcogenide (TMD) semiconductors have attracted recent interest due to their valley/spin polarization, strong binding energy, and tunability through external gate control. However, low materials quality (i.e., high defect density) has hindered efforts to understand the intrinsic properties of trions. The low photoluminescence (PL) quantum yield (QY) and short lifetime of trions have prevented harnessing them in device applications. Here, we study the behavior of trions in a series of MoSe2 monolayers, with atomic defect density varying by over 2 orders of magnitude. The QY increases with decreasing defect density and approaches unity in the cleanest material. Simultaneous measurement of the PL lifetime yields both the intrinsic radiative lifetime and the defect-dependent nonradiative lifetime. The long lifetime of ∼230 ps of trions allows direct observation of their diffusion.
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Affiliation(s)
- Bumho Kim
- Department of Mechanical Engineering, Columbia University, New York, New York 10027, United States
| | - Yue Luo
- Department of Physics, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
- Center for Nanoscale Systems, Harvard University, Cambridge, Massachusetts 02138, United States
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Daniel Rhodes
- Department of Mechanical Engineering, Columbia University, New York, New York 10027, United States
| | - Yusong Bai
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Jue Wang
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Song Liu
- Department of Mechanical Engineering, Columbia University, New York, New York 10027, United States
| | - Abraham Jordan
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Baili Huang
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, United States
| | - Zhaochen Li
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, United States
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Jonathan Owen
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Stefan Strauf
- Department of Physics, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Katayun Barmak
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, United States
| | - Xiaoyang Zhu
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - James Hone
- Department of Mechanical Engineering, Columbia University, New York, New York 10027, United States
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4
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Jadczak J, Glazov M, Kutrowska-Girzycka J, Schindler JJ, Debus J, Ho CH, Watanabe K, Taniguchi T, Bayer M, Bryja L. Upconversion of Light into Bright Intravalley Excitons via Dark Intervalley Excitons in hBN-Encapsulated WSe 2 Monolayers. ACS NANO 2021; 15:19165-19174. [PMID: 34735768 PMCID: PMC8717626 DOI: 10.1021/acsnano.1c08286] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 10/29/2021] [Indexed: 05/19/2023]
Abstract
Semiconducting monolayers of transition-metal dichalcogenides are outstanding platforms to study both electronic and phononic interactions as well as intra- and intervalley excitons and trions. These excitonic complexes are optically either active (bright) or inactive (dark) due to selection rules from spin or momentum conservation. Exploring ways of brightening dark excitons and trions has strongly been pursued in semiconductor physics. Here, we report on a mechanism in which a dark intervalley exciton upconverts light into a bright intravalley exciton in hBN-encapsulated WSe2 monolayers. Excitation spectra of upconverted photoluminescence reveals resonances at energies 34.5 and 46.0 meV below the neutral exciton in the nominal WSe2 transparency range. The required energy gains are theoretically explained by cooling of resident electrons or by exciton scattering with Λ- or K-valley phonons. Accordingly, an elevated temperature and a moderate concentration of resident electrons are necessary for observing the upconversion resonances. The interaction process observed between the inter- and intravalley excitons elucidates the importance of dark excitons for the optics of two-dimensional materials.
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Affiliation(s)
- Joanna Jadczak
- Department
of Experimental Physics, Wrocław University
of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
- (J.J.)
| | | | - Joanna Kutrowska-Girzycka
- Department
of Experimental Physics, Wrocław University
of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | | | - Joerg Debus
- Experimental
Physics 2, TU Dortmund University, 44227 Dortmund, Germany
| | - Ching-Hwa Ho
- Graduate
Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 106, Taiwan
| | - Kenji Watanabe
- National
Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
| | - Takashi Taniguchi
- National
Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
| | - Manfred Bayer
- Experimental
Physics 2, TU Dortmund University, 44227 Dortmund, Germany
| | - Leszek Bryja
- Department
of Experimental Physics, Wrocław University
of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
- (L.B.)
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5
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Xie K, Li X, Cao T. Theory and Ab Initio Calculation of Optically Excited States-Recent Advances in 2D Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e1904306. [PMID: 31808581 DOI: 10.1002/adma.201904306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 09/19/2019] [Indexed: 05/16/2023]
Abstract
Recent studies of the optical properties of 2D materials have reported unique phenomena and features that are absent in conventional bulk semiconductors. Many of these interesting properties, such as enhanced light-matter coupling, gate-tunable photoluminescence, and unusual excitonic optical selection rules arise from the nature of the two- and multi-particle excited states such as strongly bound Wannier excitons and charged excitons. The theory, modeling, and ab initio calculations of these optically excited states in 2D materials are reviewed. Several analytical and ab initio approaches are introduced. These methods are compared with each other, revealing their relative strength and limitations. Recent works that apply these methods to a variety of 2D materials and material-defect systems are then highlighted. Understanding of the optically excited states in these systems is relevant not only for fundamental scientific research of electronic excitations and correlations, but also plays an important role in the future development of quantum information science and nano-photonics.
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Affiliation(s)
- Kaichen Xie
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, 98195, USA
| | - Xiaosong Li
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, 98195, USA
- Department of Chemistry, University of Washington, Seattle, WA, 98195, USA
| | - Ting Cao
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, 98195, USA
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6
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Jadczak J, Kutrowska-Girzycka J, Bieniek M, Kazimierczuk T, Kossacki P, Schindler JJ, Debus J, Watanabe K, Taniguchi T, Ho CH, Wójs A, Hawrylak P, Bryja L. Probing negatively charged and neutral excitons in MoS 2/hBN and hBN/MoS 2/hBN van der Waals heterostructures. NANOTECHNOLOGY 2021; 32:145717. [PMID: 33463532 DOI: 10.1088/1361-6528/abd507] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
High-quality van der Waals heterostructures assembled from hBN-encapsulated monolayer transition metal dichalcogenides enable observations of subtle optical and spin-valley properties whose identification was beyond the reach of structures exfoliated directly on standard SiO2/Si substrates. Here, we describe different van der Waals heterostructures based on uncapped single-layer MoS2 stacked onto hBN layers of different thicknesses and hBN-encapsulated monolayers. Depending on the doping level, they reveal the fine structure of excitonic complexes, i.e. neutral and charged excitons. In the emission spectra of a particular MoS2/hBN heterostructure without an hBN cap we resolve two trion peaks, T1 and T2, energetically split by about 10 meV, resembling the pair of singlet and triplet trion peaks (T S and T T ) in tungsten-based materials. The existence of these trion features suggests that monolayer MoS2 has a dark excitonic ground state, despite having a 'bright' single-particle arrangement of spin-polarized conduction bands. In addition, we show that the effective excitonic g-factor significantly depends on the electron concentration and reaches the lowest value of -2.47 for hBN-encapsulated structures, which reveals a nearly neutral doping regime. In the uncapped MoS2 structures, the excitonic g-factor varies from -1.15 to -1.39 depending on the thickness of the bottom hBN layer and decreases as a function of rising temperature.
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Affiliation(s)
- J Jadczak
- Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
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7
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Wagner K, Wietek E, Ziegler JD, Semina MA, Taniguchi T, Watanabe K, Zipfel J, Glazov MM, Chernikov A. Autoionization and Dressing of Excited Excitons by Free Carriers in Monolayer WSe_{2}. PHYSICAL REVIEW LETTERS 2020; 125:267401. [PMID: 33449708 DOI: 10.1103/physrevlett.125.267401] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 11/09/2020] [Indexed: 06/12/2023]
Abstract
We experimentally demonstrate dressing of the excited exciton states by a continuously tunable Fermi sea of free charge carriers in a monolayer semiconductor. It represents an unusual scenario of two-particle excitations of charged excitons previously inaccessible in conventional material systems. We identify excited state trions, accurately determine their binding energies in the zero-density limit for both electron- and hole-doped regimes, and observe emerging many-body phenomena at elevated doping. Combining experiment and theory we gain access to the intra-exciton coupling facilitated by the interaction with free charge carriers. We provide evidence for a process of autoionization for quasiparticles, a unique scattering pathway available for excited states in atomic systems. Finally, we demonstrate a complete transfer of the optical transition strength from the excited excitons to dressed Fermi-polaron states as well as the associated light emission from their nonequilibrium populations.
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Affiliation(s)
- Koloman Wagner
- Department of Physics, University of Regensburg, Regensburg D-93053, Germany
| | - Edith Wietek
- Department of Physics, University of Regensburg, Regensburg D-93053, Germany
| | - Jonas D Ziegler
- Department of Physics, University of Regensburg, Regensburg D-93053, Germany
| | | | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Ibaraki 305-004, Japan
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki 305-004, Japan
| | - Jonas Zipfel
- Department of Physics, University of Regensburg, Regensburg D-93053, Germany
| | | | - Alexey Chernikov
- Department of Physics, University of Regensburg, Regensburg D-93053, Germany
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8
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Exciton g-factors in monolayer and bilayer WSe 2 from experiment and theory. Nat Commun 2020; 11:4539. [PMID: 32913234 PMCID: PMC7483470 DOI: 10.1038/s41467-020-18019-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 07/28/2020] [Indexed: 11/08/2022] Open
Abstract
The optical properties of monolayer and bilayer transition metal dichalcogenide semiconductors are governed by excitons in different spin and valley configurations, providing versatile aspects for van der Waals heterostructures and devices. Here, we present experimental and theoretical studies of exciton energy splittings in external magnetic field in neutral and charged WSe2 monolayer and bilayer crystals embedded in a field effect device for active doping control. We develop theoretical methods to calculate the exciton g-factors from first principles for all possible spin-valley configurations of excitons in monolayer and bilayer WSe2 including valley-indirect excitons. Our theoretical and experimental findings shed light on some of the characteristic photoluminescence peaks observed for monolayer and bilayer WSe2. In more general terms, the theoretical aspects of our work provide additional means for the characterization of single and few-layer transition metal dichalcogenides, as well as their heterostructures, in the presence of external magnetic fields.
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9
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Glazov MM. Optical properties of charged excitons in two-dimensional semiconductors. J Chem Phys 2020; 153:034703. [PMID: 32716165 DOI: 10.1063/5.0012475] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Strong Coulomb interaction in atomically thin transition metal dichalcogenides makes these systems particularly promising for studies of excitonic physics. Of special interest are the manifestations of the charged excitons, also known as trions, in the optical properties of two-dimensional semiconductors. In order to describe the optical response of such a system, the exciton interaction with resident electrons should be explicitly taken into account. In this paper, we demonstrate that this can be done in both the trion (essentially, few-particle) and Fermi-polaron (many-body) approaches, which produce equivalent results, provided that the electron density is sufficiently low and the trion binding energy is much smaller than the exciton one. Here, we consider the oscillator strengths of the optical transitions related to the charged excitons, fine structure of trions, and Zeeman effect, as well as photoluminescence of trions illustrating the applicability of both few-particle and many-body models.
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Affiliation(s)
- M M Glazov
- Ioffe Institute, 194021 St. Petersburg, Russia
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10
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Brem S, Ekman A, Christiansen D, Katsch F, Selig M, Robert C, Marie X, Urbaszek B, Knorr A, Malic E. Phonon-Assisted Photoluminescence from Indirect Excitons in Monolayers of Transition-Metal Dichalcogenides. NANO LETTERS 2020; 20:2849-2856. [PMID: 32084315 PMCID: PMC7307964 DOI: 10.1021/acs.nanolett.0c00633] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Indexed: 05/23/2023]
Abstract
The photoluminescence (PL) spectrum of transition-metal dichalcogenides (TMDs) shows a multitude of emission peaks below the bright exciton line, and not all of them have been explained yet. Here, we study the emission traces of phonon-assisted recombinations of indirect excitons. To this end, we develop a microscopic theory describing simultaneous exciton, phonon, and photon interaction and including consistent many-particle dephasing. We explain the drastically different PL below the bright exciton in tungsten- and molybdenum-based materials as the result of different configurations of bright and momentum-dark states. In good agreement with experiments, our calculations predict that WSe2 exhibits clearly visible low-temperature PL signals stemming from the phonon-assisted recombination of momentum-dark K-K' excitons.
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Affiliation(s)
- Samuel Brem
- Department
of Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden
| | - August Ekman
- Department
of Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden
| | - Dominik Christiansen
- Institute
of Theoretical Physics, Technical University
Berlin, 10623 Berlin, Germany
| | - Florian Katsch
- Institute
of Theoretical Physics, Technical University
Berlin, 10623 Berlin, Germany
| | - Malte Selig
- Institute
of Theoretical Physics, Technical University
Berlin, 10623 Berlin, Germany
| | - Cedric Robert
- Laboratoire
de Physique et Chimie des Nano-objets (LPCNO), Université de Toulouse, INSA-CNRS-UPS, 31077 Toulouse, France
| | - Xavier Marie
- Laboratoire
de Physique et Chimie des Nano-objets (LPCNO), Université de Toulouse, INSA-CNRS-UPS, 31077 Toulouse, France
| | - Bernhard Urbaszek
- Laboratoire
de Physique et Chimie des Nano-objets (LPCNO), Université de Toulouse, INSA-CNRS-UPS, 31077 Toulouse, France
| | - Andreas Knorr
- Institute
of Theoretical Physics, Technical University
Berlin, 10623 Berlin, Germany
| | - Ermin Malic
- Department
of Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden
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11
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Shi D, Yang M, Chang B, Ai Z, Zhang K, Shao Y, Wang S, Wu Y, Hao X. Ultrasonic-Ball Milling: A Novel Strategy to Prepare Large-Size Ultrathin 2D Materials. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1906734. [PMID: 32115877 DOI: 10.1002/smll.201906734] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 02/13/2020] [Indexed: 06/10/2023]
Abstract
Large-size ultrathin 2D materials, with extensive applications in optics, medicine, biology, and semiconductor fields, can be prepared through an existing common physical and chemical process. However, the current exfoliation technologies still need to be improved upon with urgency. Herein, a novel and simple "ultrasonic-ball milling" strategy is reported to effectively obtain high quality and large size ultrathin 2D materials with complete lattice structure through the introduction of moderate sapphire (Al2 O3 ) abrasives in a liquid phase system. Ultimately numerous high-quality ultrathin h-BN, graphene, MoS2 , WS2 , and BCN nanosheets are obtained with large sizes ranging from 1-20 µm, small thickness of ≈1-3 nm and a high yield of over 20%. Utilizing shear and friction force synergistically, this strategy provides a new method and alternative for preparing and optimizing large size ultrathin 2D materials.
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Affiliation(s)
- Dong Shi
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, P. R. China
| | - Mingzhi Yang
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, P. R. China
| | - Bin Chang
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, P. R. China
| | - Zizheng Ai
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, P. R. China
| | - Kang Zhang
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, P. R. China
| | - Yongliang Shao
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, P. R. China
| | - Shouzhi Wang
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, P. R. China
| | - Yongzhong Wu
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, P. R. China
| | - Xiaopeng Hao
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, P. R. China
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