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Hu C, Cheng H, Zhou J, Zhang K, Liu X, Jiang Y. Layer Dependence of Complex Refractive Index in CrSBr. MATERIALS (BASEL, SWITZERLAND) 2024; 17:3430. [PMID: 39063721 PMCID: PMC11277651 DOI: 10.3390/ma17143430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2024] [Revised: 06/30/2024] [Accepted: 07/03/2024] [Indexed: 07/28/2024]
Abstract
CrSBr is a recently discovered two-dimensional anti-ferromagnet. It has attracted much attention due to its superior properties for potential optoelectronic and spintronic applications. However, its complex refractive index with layer dependence has not been systematically studied yet. In this work, we studied the room-temperature complex refractive indices of thin CrSBr flakes of different thicknesses in the visible light range. Using micro-reflectance spectroscopy, we measured the optical contrast of thin CrSBr flakes with respect to different substrates. The complex refractive index was extracted by modeling the optical contrast with the Fresnel equations. We extracted the band gap values of CrSBr in the few-layer limit. We determined the band gaps for monolayer, bilayer, and trilayer CrSBr to be 1.88 eV, 1.81 eV, and 1.77 eV, respectively. As a comparison, the band gap for multilayer CrSBr is outside our measured range, that is, below 1.55 eV. Our results suggest that the band gap of CrSBr decreases as thickness increases.
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Affiliation(s)
- Chao Hu
- Material Science and Engineering, Anhui University, Hefei 230601, China; (C.H.)
| | - Huanghuang Cheng
- Material Science and Engineering, Anhui University, Hefei 230601, China; (C.H.)
- Center of Free Electron Laser and High Magnetic Field, Anhui University, Hefei 230601, China
| | - Jiayuan Zhou
- Institute of Physical Science and Information Technology, Anhui University, Hefei 230601, China
| | - Kai Zhang
- School of Physics and Optoelectronics Engineering, Anhui University, Hefei 230601, China
| | - Xue Liu
- Center of Free Electron Laser and High Magnetic Field, Anhui University, Hefei 230601, China
| | - Yuxuan Jiang
- School of Physics and Optoelectronics Engineering, Anhui University, Hefei 230601, China
- Center of Free Electron Laser and High Magnetic Field, Anhui University, Hefei 230601, China
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2
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Tabataba-Vakili F, Nguyen HPG, Rupp A, Mosina K, Papavasileiou A, Watanabe K, Taniguchi T, Maletinsky P, Glazov MM, Sofer Z, Baimuratov AS, Högele A. Doping-control of excitons and magnetism in few-layer CrSBr. Nat Commun 2024; 15:4735. [PMID: 38830857 DOI: 10.1038/s41467-024-49048-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 05/22/2024] [Indexed: 06/05/2024] Open
Abstract
Magnetism in two-dimensional materials reveals phenomena distinct from bulk magnetic crystals, with sensitivity to charge doping and electric fields in monolayer and bilayer van der Waals magnet CrI3. Within the class of layered magnets, semiconducting CrSBr stands out by featuring stability under ambient conditions, correlating excitons with magnetic order and thus providing strong magnon-exciton coupling, and exhibiting peculiar magneto-optics of exciton-polaritons. Here, we demonstrate that both exciton and magnetic transitions in bilayer and trilayer CrSBr are sensitive to voltage-controlled field-effect charging, exhibiting bound exciton-charge complexes and doping-induced metamagnetic transitions. Moreover, we demonstrate how these unique properties enable optical probes of local magnetic order, visualizing magnetic domains of competing phases across metamagnetic transitions induced by magnetic field or electrostatic doping. Our work identifies few-layer CrSBr as a rich platform for exploring collaborative effects of charge, optical excitations, and magnetism.
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Affiliation(s)
- Farsane Tabataba-Vakili
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539, München, Germany.
- Munich Center for Quantum Science and Technology (MCQST), 80799, München, Germany.
| | - Huy P G Nguyen
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539, München, Germany
| | - Anna Rupp
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539, München, Germany
| | - Kseniia Mosina
- Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technická 5, 166 28, Prague 6, Czech Republic
| | - Anastasios Papavasileiou
- Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technická 5, 166 28, Prague 6, Czech Republic
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | | | | | - Zdenek Sofer
- Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technická 5, 166 28, Prague 6, Czech Republic
| | - Anvar S Baimuratov
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539, München, Germany.
| | - Alexander Högele
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539, München, Germany.
- Munich Center for Quantum Science and Technology (MCQST), 80799, München, Germany.
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3
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Ziebel ME, Feuer ML, Cox J, Zhu X, Dean CR, Roy X. CrSBr: An Air-Stable, Two-Dimensional Magnetic Semiconductor. NANO LETTERS 2024; 24:4319-4329. [PMID: 38567828 DOI: 10.1021/acs.nanolett.4c00624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2024]
Abstract
The discovery of magnetic order at the 2D limit has sparked new exploration of van der Waals magnets for potential use in spintronics, magnonics, and quantum information applications. However, many of these materials feature low magnetic ordering temperatures and poor air stability, limiting their fabrication into practical devices. In this Mini-Review, we present a promising material for fundamental studies and functional use: CrSBr, an air-stable, two-dimensional magnetic semiconductor. Our discussion highlights experimental research on bulk CrSBr, including quasi-1D semiconducting properties, A-type antiferromagnetic order (TN = 132 K), and strong coupling between its electronic and magnetic properties. We then discuss the behavior of monolayer and few-layer flakes and present a perspective on promising avenues for further studies on CrSBr.
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Affiliation(s)
- Michael E Ziebel
- Columbia University, Department of Chemistry, New York, New York 10027, United States
| | - Margalit L Feuer
- Columbia University, Department of Chemistry, New York, New York 10027, United States
| | - Jordan Cox
- Columbia University, Department of Chemistry, New York, New York 10027, United States
| | - Xiaoyang Zhu
- Columbia University, Department of Chemistry, New York, New York 10027, United States
| | - Cory R Dean
- Columbia University, Department of Physics, New York, New York 10027, United States
| | - Xavier Roy
- Columbia University, Department of Chemistry, New York, New York 10027, United States
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4
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Lin K, Sun X, Dirnberger F, Li Y, Qu J, Wen P, Sofer Z, Söll A, Winnerl S, Helm M, Zhou S, Dan Y, Prucnal S. Strong Exciton-Phonon Coupling as a Fingerprint of Magnetic Ordering in van der Waals Layered CrSBr. ACS NANO 2024; 18:2898-2905. [PMID: 38240736 PMCID: PMC10832030 DOI: 10.1021/acsnano.3c07236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 01/11/2024] [Accepted: 01/16/2024] [Indexed: 01/31/2024]
Abstract
The layered, air-stable van der Waals antiferromagnetic compound CrSBr exhibits pronounced coupling among its optical, electronic, and magnetic properties. As an example, exciton dynamics can be significantly influenced by lattice vibrations through exciton-phonon coupling. Using low-temperature photoluminescence spectroscopy, we demonstrate the effective coupling between excitons and phonons in nanometer-thick CrSBr. By careful analysis, we identify that the satellite peaks predominantly arise from the interaction between the exciton and an optical phonon with a frequency of 118 cm-1 (∼14.6 meV) due to the out-of-plane vibration of Br atoms. Power-dependent and temperature-dependent photoluminescence measurements support exciton-phonon coupling and indicate a coupling between magnetic and optical properties, suggesting the possibility of carrier localization in the material. The presence of strong coupling between the exciton and the lattice may have important implications for the design of light-matter interactions in magnetic semiconductors and provide insights into the exciton dynamics in CrSBr. This highlights the potential for exploiting exciton-phonon coupling to control the optical properties of layered antiferromagnetic materials.
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Affiliation(s)
- Kaiman Lin
- University
of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai
Jiao Tong University, 20024 Shanghai, People’s Republic of China
- Institute
of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - Xiaoxiao Sun
- Institute
of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - Florian Dirnberger
- Institute
of Applied Physics and Würzburg-Dresden Cluster of Excellence
ct.qmat, Technische Universität Dresden, 01062 Dresden, Germany
| | - Yi Li
- Institute
of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
- Technische
Universität Dresden, 01062 Dresden, Germany
| | - Jiang Qu
- Leibniz
Institute for Solid State and Materials Research Dresden (IFW Dresden), Helmholtzstraße 20, 01069 Dresden, Germany
| | - Peiting Wen
- Institute
of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
- Technische
Universität Dresden, 01062 Dresden, Germany
| | - Zdenek Sofer
- Department
of Inorganic Chemistry, University of Chemistry
and Technology Prague, Technická 5, 16628 Prague 6, Czech Republic
| | - Aljoscha Söll
- Department
of Inorganic Chemistry, University of Chemistry
and Technology Prague, Technická 5, 16628 Prague 6, Czech Republic
| | - Stephan Winnerl
- Institute
of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - Manfred Helm
- Institute
of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
- Technische
Universität Dresden, 01062 Dresden, Germany
| | - Shengqiang Zhou
- Institute
of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
| | - Yaping Dan
- University
of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai
Jiao Tong University, 20024 Shanghai, People’s Republic of China
| | - Slawomir Prucnal
- Institute
of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany
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5
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Serati de Brito C, Faria Junior PE, Ghiasi TS, Ingla-Aynés J, Rabahi CR, Cavalini C, Dirnberger F, Mañas-Valero S, Watanabe K, Taniguchi T, Zollner K, Fabian J, Schüller C, van der Zant HSJ, Gobato YG. Charge Transfer and Asymmetric Coupling of MoSe 2 Valleys to the Magnetic Order of CrSBr. NANO LETTERS 2023. [PMID: 38019289 DOI: 10.1021/acs.nanolett.3c03431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
van der Waals heterostructures composed of two-dimensional (2D) transition metal dichalcogenides and vdW magnetic materials offer an intriguing platform to functionalize valley and excitonic properties in nonmagnetic TMDs. Here, we report magneto photoluminescence (PL) investigations of monolayer (ML) MoSe2 on the layered A-type antiferromagnetic (AFM) semiconductor CrSBr under different magnetic field orientations. Our results reveal a clear influence of the CrSBr magnetic order on the optical properties of MoSe2, such as an anomalous linear-polarization dependence, changes of the exciton/trion energies, a magnetic-field dependence of the PL intensities, and a valley g-factor with signatures of an asymmetric magnetic proximity interaction. Furthermore, first-principles calculations suggest that MoSe2/CrSBr forms a broken-gap (type-III) band alignment, facilitating charge transfer processes. The work establishes that antiferromagnetic-nonmagnetic interfaces can be used to control the valley and excitonic properties of TMDs, relevant for the development of opto-spintronics devices.
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Affiliation(s)
- Caique Serati de Brito
- Physics Department, Federal University of São Carlos, São Carlos, SP 13565-905, Brazil
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, D-93040 Regensburg, Germany
| | - Paulo E Faria Junior
- Institute for Theoretical Physics, University of Regensburg, D-93040 Regensburg, Germany
| | - Talieh S Ghiasi
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Josep Ingla-Aynés
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - César Ricardo Rabahi
- Physics Department, Federal University of São Carlos, São Carlos, SP 13565-905, Brazil
| | - Camila Cavalini
- Physics Department, Federal University of São Carlos, São Carlos, SP 13565-905, Brazil
| | - Florian Dirnberger
- Institute of Applied Physics and Würzburg-Dresden Cluster of Excellence ct.qmat, Technische Universität, 01069 Dresden, Germany
| | - Samuel Mañas-Valero
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
- Instituto de Ciencia Molecular (ICMol), Universitat de València, Catedrático José Beltrán 2, Paterna 46980, Spain
| | - Kenji Watanabe
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Klaus Zollner
- Institute for Theoretical Physics, University of Regensburg, D-93040 Regensburg, Germany
| | - Jaroslav Fabian
- Institute for Theoretical Physics, University of Regensburg, D-93040 Regensburg, Germany
| | - Christian Schüller
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, D-93040 Regensburg, Germany
| | - Herre S J van der Zant
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Yara Galvão Gobato
- Physics Department, Federal University of São Carlos, São Carlos, SP 13565-905, Brazil
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