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Jalil AR, Schüffelgen P, Valencia H, Schleenvoigt M, Ringkamp C, Mussler G, Luysberg M, Mayer J, Grützmacher D. Selective Area Epitaxy of Quasi-1-Dimensional Topological Nanostructures and Networks. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:354. [PMID: 36678107 PMCID: PMC9863233 DOI: 10.3390/nano13020354] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 06/17/2023]
Abstract
Quasi-one-dimensional (1D) topological insulators hold the potential of forming the basis of novel devices in spintronics and quantum computing. While exposure to ambient conditions and conventional fabrication processes are an obstacle to their technological integration, ultra-high vacuum lithography techniques, such as selective area epitaxy (SAE), provide all the necessary ingredients for their refinement into scalable device architectures. In this work, high-quality SAE of quasi-1D topological insulators on templated Si substrates is demonstrated. After identifying the narrow temperature window for selectivity, the flexibility and scalability of this approach is revealed. Compared to planar growth of macroscopic thin films, selectively grown regions are observed to experience enhanced growth rates in the nanostructured templates. Based on these results, a growth model is deduced, which relates device geometry to effective growth rates. After validating the model experimentally for various three-dimensional topological insulators (3D TIs), the crystal quality of selectively grown nanostructures is optimized by tuning the effective growth rates to 5 nm/h. The high quality of selectively grown nanostructures is confirmed through detailed structural characterization via atomically resolved scanning transmission electron microscopy (STEM).
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Affiliation(s)
- Abdur Rehman Jalil
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany
- JARA-FIT (Fundamentals of Future Information Technology), Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany
- Peter Grünberg Institute (PGI-10), JARA-Green IT, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Peter Schüffelgen
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany
- JARA-FIT (Fundamentals of Future Information Technology), Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany
| | - Helen Valencia
- JARA-FIT (Fundamentals of Future Information Technology), Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany
- Ernst Ruska-Centre (ER-C) for Microscopy and Spectroscopy with Electrons, Forschungszentrum Juelich, 52425 Jülich, Germany
| | - Michael Schleenvoigt
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany
- JARA-FIT (Fundamentals of Future Information Technology), Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany
| | - Christoph Ringkamp
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany
- JARA-FIT (Fundamentals of Future Information Technology), Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany
| | - Gregor Mussler
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany
- JARA-FIT (Fundamentals of Future Information Technology), Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany
| | - Martina Luysberg
- Ernst Ruska-Centre (ER-C) for Microscopy and Spectroscopy with Electrons, Forschungszentrum Juelich, 52425 Jülich, Germany
| | - Joachim Mayer
- Ernst Ruska-Centre (ER-C) for Microscopy and Spectroscopy with Electrons, Forschungszentrum Juelich, 52425 Jülich, Germany
- Central Facility for Electron Microscopy (GFE), RWTH Aachen University, 52074 Aachen, Germany
| | - Detlev Grützmacher
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany
- JARA-FIT (Fundamentals of Future Information Technology), Jülich-Aachen Research Alliance, Forschungszentrum Jülich and RWTH Aachen University, 52425 Jülich, Germany
- Peter Grünberg Institute (PGI-10), JARA-Green IT, Forschungszentrum Jülich, 52425 Jülich, Germany
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Abstract
2D layered materials with diverse exciting properties have recently attracted tremendous interest in the scientific community. Layered topological insulator Bi2Se3 comes into the spotlight as an exotic state of quantum matter with insulating bulk states and metallic Dirac-like surface states. Its unique crystal and electronic structure offer attractive features such as broadband optical absorption, thickness-dependent surface bandgap and polarization-sensitive photoresponse, which enable 2D Bi2Se3 to be a promising candidate for optoelectronic applications. Herein, we present a comprehensive summary on the recent advances of 2D Bi2Se3 materials. The structure and inherent properties of Bi2Se3 are firstly described and its preparation approaches (i.e., solution synthesis and van der Waals epitaxy growth) are then introduced. Moreover, the optoelectronic applications of 2D Bi2Se3 materials in visible-infrared detection, terahertz detection, and opto-spintronic device are discussed in detail. Finally, the challenges and prospects in this field are expounded on the basis of current development.
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Affiliation(s)
- Fakun K. Wang
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Sijie J. Yang
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Tianyou Y. Zhai
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
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Hwang W, Yoo SH, Soon A, Jang W. Going beyond the equilibrium crystal shape: re-tracing the morphological evolution in group 5 tetradymite nanocrystals. NANOSCALE 2021; 13:15721-15730. [PMID: 34524344 DOI: 10.1039/d1nr04793k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Nanocrystals of group 5 tetradymites M2X3 (where M = Bi and Sb, X = Se and Te) are of high technological relevance in modern topological nanoelectronics. However, there is a current lack of a systematic understanding to predict the preferred nanocrystal morphology in experiments where commonly-used equilibrium thermodynamic models appear to fail. In this work, using first-principles DFT calculations with a rationally-extended ab initio atomistic thermodynamics approach coupled to implicit solvation models and Gibbs-Wulff shape constructions, we demonstrate that this absence of predictive power stems from the limitation of equilibrium thermodynamics. By re-tracing and carefully addressing with a more realistic chemical potential definition, we illustrate this shortcoming can be overcome and afford a more rational route to size-engineer and shape-design highly-functional group 5 tetradymite nanoparticles for targeted applications.
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Affiliation(s)
- Woohyun Hwang
- Department of Materials Science & Engineering and Center for Artificial Synesthesia Materials Discovery, Yonsei University, Seoul 03722, Republic of Korea.
| | - Su-Hyun Yoo
- Department of Computational Materials Design, Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Düsseldorf, Germany
| | - Aloysius Soon
- Department of Materials Science & Engineering and Center for Artificial Synesthesia Materials Discovery, Yonsei University, Seoul 03722, Republic of Korea.
- School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Woosun Jang
- Department of Materials Science & Engineering and Center for Artificial Synesthesia Materials Discovery, Yonsei University, Seoul 03722, Republic of Korea.
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Wang J, Tang J. Fe-based Fenton-like catalysts for water treatment: Preparation, characterization and modification. CHEMOSPHERE 2021; 276:130177. [PMID: 33714147 DOI: 10.1016/j.chemosphere.2021.130177] [Citation(s) in RCA: 93] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/06/2021] [Accepted: 02/27/2021] [Indexed: 06/12/2023]
Abstract
Fenton reaction based on hydroxyl radicals () is effective for environment remediation. Nevertheless, the conventional Fenton reaction has several disadvantages, such as working at acidic pH, producing iron-containing sludge, and the difficulty in catalysts reuse. Fenton-like reaction using solid catalysts rather than Fe2+ has received increasing attention. To date, Fe-based catalysts have received increasing attention due to their earth abundance, good biocompatibility, comparatively low toxicity and ready availability, it is necessary to review the current status of Fenton-like catalysts. In this review, the recent advances in Fe-based Fenton-like catalysts were systematically analyzed and summarized. Firstly, the various preparation methods were introduced, including template-free methods (precipitation, sol gel, impregnation, hydrothermal, thermal, and others) and template-based methods (hard-templating method and soft-templating method); then, the characterization techniques for Fe-based catalysts were summarized, such as X-ray diffraction (XRD), Brunauer, Emmett and Teller (BET), SEM (scanning electron microscopy)/TEM (transmission electron microscopy)/HRTEM (high-resolution TEM), FTIR (Fourier transform infrared spectroscopy)/Raman, XPS (X-ray photoelectron spectroscopy), 57Fe Mössbauer spectroscopy etc.; thirdly, some important conventional Fe-based catalysts were introduced, including iron oxides and oxyhydroxides, zero-valent iron (ZVI) and iron disulfide and oxychloride; fourthly, the modification strategies of Fe-based catalysts were discussed, such as microstructure controlling, introduction of support materials, construction of core-shell structure and incorporation of new metal-containing component; Finally, concluding remarks were given and the future perspectives for further study were discussed. This review will provide important information to further advance the development and application of Fe-based catalysts for water treatment.
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Affiliation(s)
- Jianlong Wang
- Laboratory of Environmental Technology, INET, Tsinghua University, Beijing, 100084, PR China; Beijing Key Laboratory of Radioactive Waste Treatment, Tsinghua University, Beijing, 100084, PR China.
| | - Juntao Tang
- Laboratory of Environmental Technology, INET, Tsinghua University, Beijing, 100084, PR China
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Synthesis and characterization of a Sb 2Te 3/Bi 2Te 3 p-n junction heterostructure via electrodeposition in nanoporous membranes. iScience 2021; 24:102694. [PMID: 34195570 PMCID: PMC8233195 DOI: 10.1016/j.isci.2021.102694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 05/24/2021] [Accepted: 06/03/2021] [Indexed: 11/22/2022] Open
Abstract
Topological insulators (TIs) are bulk insulators with metallic surface states that can be described by a single Dirac cone. However, low-dimensional solids such as nanowires (NWs) are a challenge, due to the difficulty of separating surface contributions from bulk carriers. Fabrication of NWs with high surface-to-volume ratio can be realized by different methods such as chemical vapor transport, molecular beam epitaxy, and electrodeposition. The last method is used in the present work allowing the growth of structures such as p-n junctions, intercalation of magnetic or superconducting dots. We report the synthesis of high-quality TI NW: Bi2Te3, Sb2Te3 and p-n junction via electrodeposition. Structural, morphological, and nanostructure properties of NWs have been investigated by various characterization techniques. Interface structures and lateral heterojunctions (LHJ) in p-n junction NWs has also been made.
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Hatta S, Obayashi K, Okuyama H, Aruga T. Metallic conduction through van der Waals interfaces in ultrathin [Formula: see text] films. Sci Rep 2021; 11:5742. [PMID: 33707477 PMCID: PMC7952583 DOI: 10.1038/s41598-021-85078-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 02/24/2021] [Indexed: 11/18/2022] Open
Abstract
While the van der Waals (vdW) interface in layered materials hinders the transport of charge carriers in the vertical direction, it serves a good horizontal conduction path. We have investigated electrical conduction of few quintuple-layer (QL) [Formula: see text] films by in situ four-point probe conductivity measurement. The impact of the vdW (Te-Te) interface appeared as a large conductivity increase with increasing thickness from 1 to 2 QL. Angle-resolved photoelectron spectroscopy and first-principles calculations reveal the confinement of bulk-like conduction band (CB) state into the vdW interface. Our analysis based on the Boltzmann equation showed that the conduction of the CB has a long mean free path compared to the surface-state conduction. This is mainly attributed to the spatial separation of the CB electrons and the donor defects located at the Bi sites.
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Affiliation(s)
- Shinichiro Hatta
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan
| | - Ko Obayashi
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan
| | - Hiroshi Okuyama
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan
| | - Tetsuya Aruga
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan
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Wu T, Kim J, Myung NV. Electrochemical Mechanism of Tellurium Reduction in Alkaline Medium. Front Chem 2020; 8:84. [PMID: 32195220 PMCID: PMC7062915 DOI: 10.3389/fchem.2020.00084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 01/27/2020] [Indexed: 11/13/2022] Open
Abstract
A systematic electrochemical study was conducted to investigate the reduction of tellurium (Te) in alkaline solutions. The effect of various parameters, including tellurite ion concentration, applied potential, and pH was investigated by both linear sweep voltammograms (LSVs) and electrochemical quartz crystal microbalance (EQCM). EQCM was essential to understand the reduction of Te(0) to solubleTe 2 2 - (-I) or Te2-(-II). The Tafel slopes for two Te reduction reactions [i.e., Te(IV) to Te(0) and Te(0) to Te(-I)] indicated that the electrochemical reduction of Te is strongly dependent on solution pH, whereas it is independent of the concentration ofTeO 3 2 - . At relatively weaker alkaline solutions (i.e., pH ≤ 12.5), the discharge ofTe ( OH ) 3 + was determined to be the rate-limiting step during the reduction of Te(IV) to Te(0). For the reduction of Te(0) to Te(-I), the reaction follows a four-step reaction, which consisted of two discharge and two electrochemical reactions. The second discharge reaction was the rate-limiting step when pH ≤12.5 with the Tafel slope of 120 mV/decade. At a higher pH of 14.7, the Tafel slope was shifted to be 40 mV/decade, which indicated that the rate-limiting step was altered to the second electrochemical reaction. Te(0) deposits were found either on the surface of an electrode or in the solution depending on pH due to the different rate-limiting reactions, revealing that pH was a key parameter to dictate the morphology of the Te(0) deposits in alkaline media.
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Affiliation(s)
- Tingjun Wu
- Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA, United States
- Laboratory of Advanced Functional Materials, Xiamen Institute of Rare-earth Materials, Haixi Institute, Chinese Academy of Sciences, Xiamen, China
| | - Jiwon Kim
- Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA, United States
- Materials Science and Chemical Engineering Center, Institute for Advanced Engineering, Yongin-si, South Korea
| | - Nosang V. Myung
- Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA, United States
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8
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Claro MS, Levy I, Gangopadhyay A, Smith DJ, Tamargo MC. Self-assembled Bismuth Selenide (Bi 2Se 3) quantum dots grown by molecular beam epitaxy. Sci Rep 2019; 9:3370. [PMID: 30833604 PMCID: PMC6399346 DOI: 10.1038/s41598-019-39821-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 01/28/2019] [Indexed: 11/25/2022] Open
Abstract
We report the growth of self-assembled Bi2Se3 quantum dots (QDs) by molecular beam epitaxy on GaAs substrates using the droplet epitaxy technique. The QD formation occurs after anneal of Bismuth droplets under Selenium flux. Characterization by atomic force microscopy, scanning electron microscopy, X-ray diffraction, high-resolution transmission electron microscopy and X-ray reflectance spectroscopy is presented. Raman spectra confirm the QD quality. The quantum dots are crystalline, with hexagonal shape, and have average dimensions of 12-nm height (12 quintuple layers) and 46-nm width, and a density of 8.5 × 109 cm−2. This droplet growth technique provides a means to produce topological insulator QDs in a reproducible and controllable way, providing convenient access to a promising quantum material with singular spin properties.
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Affiliation(s)
- Marcel S Claro
- Department of Chemistry, The City College of New York, New York, NY, 10031, USA.,INL - International Iberian Nanotechnology Laboratory, 4715-330, Braga, Portugal
| | - Ido Levy
- Department of Chemistry, The City College of New York, New York, NY, 10031, USA.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - Abhinandan Gangopadhyay
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, 85287, USA
| | - David J Smith
- Department of Physics, Arizona State University, Tempe, AZ, 85287, USA
| | - Maria C Tamargo
- Department of Chemistry, The City College of New York, New York, NY, 10031, USA. .,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA.
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9
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Wang YR, Lee P, Zhang BT, Sang YH, He JL, Liu H, Lee CK. Optical nonlinearity engineering of a bismuth telluride saturable absorber and application of a pulsed solid state laser therein. NANOSCALE 2017; 9:19100-19107. [PMID: 29143038 DOI: 10.1039/c7nr06004a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Saturable absorbers (SAs) have interesting applications for the realization of pulsed lasers in various wavelengths of fiber and solid-state lasers. Topological insulators (TIs) have been recently discovered to feature saturable absorption due to their unique band structure. In this study, high-purity layers of Bi2Te3 thin film SA have been successfully prepared using the spin coating-coreduction approach (SCCA). Compared with the typical method of preparing SAs, the SCCA can be used to prepare topological insulator saturable absorbers (TISAs) with high optical quality, large area consistency, and controllable thickness, which is critical for pulsed lasers. To the best of our knowledge, this study is the first observation and discussion of clear thickness-dependent optical nonlinearity. In this study, a Q-switched bulk Nd:YAG laser is demonstrated and investigated using the prepared TISA as the absorber. The timing jitter and amplitude fluctuation of the stable pulse laser indicated that the SCCA is suitable for fabricating a Bi2Te3 SA. Furthermore, the SCCA enables the establishment of a pulsing laser through saturation intensity engineering.
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Affiliation(s)
- Yi-Ran Wang
- Department of Photonics, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan.
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10
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Trivedi T, Roy A, Movva HCP, Walker ES, Bank SR, Neikirk DP, Banerjee SK. Versatile Large-Area Custom-Feature van der Waals Epitaxy of Topological Insulators. ACS NANO 2017; 11:7457-7467. [PMID: 28692797 DOI: 10.1021/acsnano.7b03894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
As the focus of applied research in topological insulators (TI) evolves, the need to synthesize large-area TI films for practical device applications takes center stage. However, constructing scalable and adaptable processes for high-quality TI compounds remains a challenge. To this end, a versatile van der Waals epitaxy (vdWE) process for custom-feature bismuth telluro-sulfide TI growth and fabrication is presented, achieved through selective-area fluorination and modification of surface free-energy on mica. The TI features grow epitaxially in large single-crystal trigonal domains, exhibiting armchair or zigzag crystalline edges highly oriented with the underlying mica lattice and only two preferred domain orientations mirrored at 180°. As-grown feature thickness dependence on lateral dimensions and denuded zones at boundaries are observed, as explained by a semiempirical two-species surface migration model with robust estimates of growth parameters and elucidating the role of selective-area surface modification. Topological surface states contribute up to 60% of device conductance at room temperature, indicating excellent electronic quality. High-yield microfabrication and the adaptable vdWE growth mechanism with readily alterable precursor and substrate combinations lend the process versatility to realize crystalline TI synthesis in arbitrary shapes and arrays suitable for facile integration with processes ranging from rapid prototyping to scalable manufacturing.
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Affiliation(s)
- Tanuj Trivedi
- Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin , Austin, Texas 78758, United States
| | - Anupam Roy
- Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin , Austin, Texas 78758, United States
| | - Hema C P Movva
- Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin , Austin, Texas 78758, United States
| | - Emily S Walker
- Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin , Austin, Texas 78758, United States
| | - Seth R Bank
- Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin , Austin, Texas 78758, United States
| | - Dean P Neikirk
- Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin , Austin, Texas 78758, United States
| | - Sanjay K Banerjee
- Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin , Austin, Texas 78758, United States
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Bhunia H, Bar A, Bera A, Pal AJ. Simultaneous observation of surface- and edge-states of a 2D topological insulator through scanning tunneling spectroscopy and differential conductance imaging. Phys Chem Chem Phys 2017; 19:9872-9878. [DOI: 10.1039/c7cp00149e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Gapless edge-states with a Dirac point below the Fermi energy and band-edges at the interior observed in 2D topological insulators.
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Affiliation(s)
- Hrishikesh Bhunia
- Department of Solid State Physics
- Indian Association for the Cultivation of Science
- Jadavpur
- Kolkata 700032
- India
| | - Abhijit Bar
- Department of Solid State Physics
- Indian Association for the Cultivation of Science
- Jadavpur
- Kolkata 700032
- India
| | - Abhijit Bera
- Department of Solid State Physics
- Indian Association for the Cultivation of Science
- Jadavpur
- Kolkata 700032
- India
| | - Amlan J. Pal
- Department of Solid State Physics
- Indian Association for the Cultivation of Science
- Jadavpur
- Kolkata 700032
- India
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12
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Schönherr P, Zhang F, Kojda D, Mitdank R, Albrecht M, Fischer SF, Hesjedal T. Free-standing millimetre-long Bi2Te3 sub-micron belts catalyzed by TiO2 nanoparticles. NANOSCALE RESEARCH LETTERS 2016; 11:308. [PMID: 27342602 PMCID: PMC4920739 DOI: 10.1186/s11671-016-1510-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 05/30/2016] [Indexed: 06/06/2023]
Abstract
Physical vapour deposition (PVD) is used to grow millimetre-long Bi2Te3 sub-micron belts catalysed by TiO2 nanoparticles. The catalytic efficiency of TiO2 nanoparticles for the nanostructure growth is compared with the catalyst-free growth employing scanning electron microscopy. The catalyst-coated and catalyst-free substrates are arranged side-by-side, and overgrown at the same time, to assure identical growth conditions in the PVD furnace. It is found that the catalyst enhances the yield of the belts. Very long belts were achieved with a growth rate of 28 nm/min. A ∼1-mm-long belt with a rectangular cross section was obtained after 8 h of growth. The thickness and width were determined by atomic force microscopy, and their ratio is ∼1:10. The chemical composition was determined to be stoichiometric Bi2Te3 using energy-dispersive X-ray spectroscopy. Temperature-dependent conductivity measurements show a characteristic increase of the conductivity at low temperatures. The room temperature conductivity of 0.20 × 10(5) S m (-1) indicates an excellent sample quality.
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Affiliation(s)
- Piet Schönherr
- />Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU UK
| | - Fengyu Zhang
- />Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU UK
- />University of Science and Technology of China, Jinzhai Rd. 96, Hefei, 230026 China
| | - Danny Kojda
- />Humboldt-Universität zu Berlin, Newtonstr. 15, Berlin, 12489 Germany
| | - Rüdiger Mitdank
- />Humboldt-Universität zu Berlin, Newtonstr. 15, Berlin, 12489 Germany
| | - Martin Albrecht
- />Leibniz-Institut für Kristallzüchtung - IKZ, Berlin, 12489 Germany
| | - Saskia F. Fischer
- />Humboldt-Universität zu Berlin, Newtonstr. 15, Berlin, 12489 Germany
| | - Thorsten Hesjedal
- />Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU UK
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14
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Wen Y, Wang Q, Yin L, Liu Q, Wang F, Wang F, Wang Z, Liu K, Xu K, Huang Y, Shifa TA, Jiang C, Xiong J, He J. Epitaxial 2D PbS Nanoplates Arrays with Highly Efficient Infrared Response. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:8051-8057. [PMID: 27376848 DOI: 10.1002/adma.201602481] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 06/02/2016] [Indexed: 05/08/2023]
Abstract
2D nonlayered semiconductors attract intense interest due to their unique planar structure and various fascinating optoelectronic properties. Here, a method is developed to design orientation-controlled and well-defined single-crystalline PbS nanoplates arrays on mica. Furthermore, the single PbS nanoplate device displays great photoresponsivity, detectivity, and photogain values as high as 1621 A W-1 , 1.72 × 1011 Jones, and 2512, respectively.
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Affiliation(s)
- Yao Wen
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
- CAS Key Laboratory for Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qisheng Wang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Lei Yin
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Qi Liu
- Key Laboratory of Microelectronic Devices and Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing, 100029, China
| | - Feng Wang
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Fengmei Wang
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Zhenxing Wang
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Kaili Liu
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Kai Xu
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Yun Huang
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Tofik Ahmed Shifa
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Chao Jiang
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China.
- CAS Key Laboratory for Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing, 100190, China.
| | - Jie Xiong
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China.
| | - Jun He
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China.
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China.
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