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Chen Z, Sui X, Li Z, Li Y, Liu X, Zhang Y. Quantum-sized topological insulators/semimetals enable ultrahigh and broadband saturable absorption. NANOSCALE HORIZONS 2023; 8:1686-1694. [PMID: 37702034 DOI: 10.1039/d3nh00282a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
Two-dimensional topological insulators/semimetals have recently attracted much attention. However, quantum-sized topological insulators/semimetals with intrinsic characteristics have never been reported before. Herein, we report the high-yield production of topological insulator (i.e., Bi2Se3 and Sb2Te3) and semimetal (i.e., TiS2) quantum sheets (QSs) with monolayer structures and sub-4 nm lateral sizes. Both linear and nonlinear optical performances of the QSs are investigated. The QS dispersions present remarkable photoluminescence with excitation wavelength-, concentration-, and solvent-dependence. The solution-processed QSs-poly(methyl methacrylate) (PMMA) hybrid thin films demonstrate exceptional nonlinear saturation absorption (NSA). Particularly, Bi2Se3 QSs-PMMA enables record-high NSA performance with a broadband feature. Specifically, the (absolute) modulation depths up to 71.6 and 72.4% and saturation intensities down to 1.52 and 0.49 MW cm-2 are achieved at 532 and 800 nm, respectively. Such a phenomenal NSA performance would greatly facilitate their applications in mode-locked lasers and related fields.
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Affiliation(s)
- Zhexue Chen
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P. R. China.
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Xinyu Sui
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P. R. China
| | - Zhangqiang Li
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P. R. China.
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yueqi Li
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P. R. China.
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Xinfeng Liu
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P. R. China
| | - Yong Zhang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P. R. China.
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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Adhikari S, Mandal S, Kim DH. Recent Development Strategies for Bismuth-Driven Materials in Sustainable Energy Systems and Environmental Restoration. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2206003. [PMID: 36526436 DOI: 10.1002/smll.202206003] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/20/2022] [Indexed: 06/17/2023]
Abstract
Bismuth(Bi)-based materials have gained considerable attention in recent decades for use in a diverse range of sustainable energy and environmental applications due to their low toxicity and eco-friendliness. Bi materials are widely employed in electrochemical energy storage and conversion devices, exhibiting excellent catalytic and non-catalytic performance, as well as CO2 /N2 reduction and water treatment systems. A variety of Bi materials, including its oxides, chalcogenides, oxyhalides, bismuthates, and other composites, have been developed for understanding their physicochemical properties. In this review, a comprehensive overview of the properties of individual Bi material systems and their use in a range of applications is provided. This review highlights the implementation of novel strategies to modify Bi materials based on morphological and facet control, doping/defect inclusion, and composite/heterojunction formation. The factors affecting the development of different classes of Bi materials and how their control differs between individual Bi compounds are also described. In particular, the development process for these material systems, their mass production, and related challenges are considered. Thus, the key components in Bi compounds are compared in terms of their properties, design, and applications. Finally, the future potential and challenges associated with Bi complexes are presented as a pathway for new innovations.
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Affiliation(s)
- Sangeeta Adhikari
- School of Chemical Engineering, Chonnam National University, 77 Yongbong-ro, Gwangju, 61186, Republic of Korea
- Catalyst Research Institute, Chonnam National University, 77, Yongbong-ro, Buk-gu, Gwangju, 61186, Republic of Korea
| | - Sandip Mandal
- School of Earth Science and Environmental Engineering, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Oryong-dong, Buk-gu, Gwangju, 61005, Republic of Korea
| | - Do-Heyoung Kim
- School of Chemical Engineering, Chonnam National University, 77 Yongbong-ro, Gwangju, 61186, Republic of Korea
- Catalyst Research Institute, Chonnam National University, 77, Yongbong-ro, Buk-gu, Gwangju, 61186, Republic of Korea
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Optical manipulation of Rashba-split 2-dimensional electron gas. Nat Commun 2022; 13:3096. [PMID: 35654938 PMCID: PMC9163084 DOI: 10.1038/s41467-022-30742-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 05/16/2022] [Indexed: 11/17/2022] Open
Abstract
In spintronics, the two main approaches to actively control the electrons’ spin involve static magnetic or electric fields. An alternative avenue relies on the use of optical fields to generate spin currents, which can bolster spin-device performance, allowing for faster and more efficient logic. To date, research has mainly focused on the optical injection of spin currents through the photogalvanic effect, and little is known about the direct optical control of the intrinsic spin-splitting. To explore the optical manipulation of a material’s spin properties, we consider the Rashba effect. Using time- and angle-resolved photoemission spectroscopy (TR-ARPES), we demonstrate that an optical excitation can tune the Rashba-induced spin splitting of a two-dimensional electron gas at the surface of Bi2Se3. We establish that light-induced photovoltage and charge carrier redistribution - which in concert modulate the Rashba spin-orbit coupling strength on a sub-picosecond timescale - can offer an unprecedented platform for achieving optically-driven spin logic devices. The major challenge for the development of spin based information processing is to obtain efficient ways of controlling spin. Here, Michiardi et al show that the Rashba spin-splitting at the surface of Bi2Se3 topological insulator can be controlled via optical pulses on picosecond timescales.
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Das SK, Padhan P. The effect of mechanical strain on the Dirac surface states in the (0001) surface and the cohesive energy of the topological insulator Bi 2Se 3. NANOSCALE ADVANCES 2021; 3:4816-4825. [PMID: 36134302 PMCID: PMC9416801 DOI: 10.1039/d1na00139f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 07/07/2021] [Indexed: 05/21/2023]
Abstract
The band gap (E g) engineering and Dirac point tuning of the (0001) surface of 8 QLs (quintuple layers) thick Bi2Se3 slab are explored using the first-principles density functional theory calculations by varying the strain. The strain on the Bi2Se3 slab primarily varies the bandwidth, modifies the p z - orbital population of Bi and moves the Dirac point of the (0001) surface of Bi2Se3. The Dirac cone feature of the (0001) surface of Bi2Se3 is preserved for the entire range of the biaxial strain. However, around 5% tensile uniaxial strain and even lower value of volume conservation strain annihilate the Dirac cone, which causes the loss of topological (0001) surface states of Bi2Se3. The biaxial strain provides ease in achieving the Dirac cone at the Fermi energy (E F) than the uniaxial and volume conservation strains. Interestingly, the transition from direct E g to indirect E g state of the (0001) surface of Bi2Se3 is observed in the volume conservation strain-dependent E g. The strain on Bi2Se3, significantly modifies the conduction band of Se2 atoms near E F compared to Bi and Se1, and plays a vital role in the conduction of the (0001) surface of Bi2Se3. The atomic cohesive energy of the Bi2Se3 slab is very close to that of (0001) oriented nanocrystals extracted from the Raman spectra. The strain-dependent cohesive energy indicates that at a higher value of strain, the uniaxial and volume conservation strain provides better stability than that of the biaxial strain (0001) oriented growth of the Bi2Se3 nanocrystals. Our study establishes the relationship between the strained lattice and electronic structures of Bi2Se3, and more generally demonstrates the tuning of the Dirac point with the mechanical strain.
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Affiliation(s)
- Soumendra Kumar Das
- Department of Physics, Indian Institute of Technology Madras Chennai 600036 Tamil Nadu India
| | - Prahallad Padhan
- Department of Physics, Indian Institute of Technology Madras Chennai 600036 Tamil Nadu India
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Aranda-Aguirre A, Ojeda J, Ferreira de Brito J, Garcia-Segura S, Boldrin Zanoni MV, Alarcon H. Photoelectrodes of Cu2O with interfacial structure of topological insulator Bi2Se3 contributes to selective photoelectrocatalytic reduction of CO2 towards methanol. J CO2 UTIL 2020. [DOI: 10.1016/j.jcou.2020.101154] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Shahbazi MA, Faghfouri L, Ferreira MPA, Figueiredo P, Maleki H, Sefat F, Hirvonen J, Santos HA. The versatile biomedical applications of bismuth-based nanoparticles and composites: therapeutic, diagnostic, biosensing, and regenerative properties. Chem Soc Rev 2020; 49:1253-1321. [PMID: 31998912 DOI: 10.1039/c9cs00283a] [Citation(s) in RCA: 163] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Studies of nanosized forms of bismuth (Bi)-containing materials have recently expanded from optical, chemical, electronic, and engineering fields towards biomedicine, as a result of their safety, cost-effective fabrication processes, large surface area, high stability, and high versatility in terms of shape, size, and porosity. Bi, as a nontoxic and inexpensive diamagnetic heavy metal, has been used for the fabrication of various nanoparticles (NPs) with unique structural, physicochemical, and compositional features to combine various properties, such as a favourably high X-ray attenuation coefficient and near-infrared (NIR) absorbance, excellent light-to-heat conversion efficiency, and a long circulation half-life. These features have rendered bismuth-containing nanoparticles (BiNPs) with desirable performance for combined cancer therapy, photothermal and radiation therapy (RT), multimodal imaging, theranostics, drug delivery, biosensing, and tissue engineering. Bismuth oxyhalides (BiOx, where X is Cl, Br or I) and bismuth chalcogenides, including bismuth oxide, bismuth sulfide, bismuth selenide, and bismuth telluride, have been heavily investigated for therapeutic purposes. The pharmacokinetics of these BiNPs can be easily improved via the facile modification of their surfaces with biocompatible polymers and proteins, resulting in enhanced colloidal stability, extended blood circulation, and reduced toxicity. Desirable antibacterial effects, bone regeneration potential, and tumor growth suppression under NIR laser radiation are the main biomedical research areas involving BiNPs that have opened up a new paradigm for their future clinical translation. This review emphasizes the synthesis and state-of-the-art progress related to the biomedical applications of BiNPs with different structures, sizes, and compositions. Furthermore, a comprehensive discussion focusing on challenges and future opportunities is presented.
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Affiliation(s)
- Mohammad-Ali Shahbazi
- Drug Research Program, Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, FI-00014 University of Helsinki, Helsinki, Finland.
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Multiple ionization state of Arq+ ions during collisions near the Bohr velocity. Sci Rep 2019; 9:5359. [PMID: 30926834 PMCID: PMC6440978 DOI: 10.1038/s41598-019-41709-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 12/12/2018] [Indexed: 11/21/2022] Open
Abstract
In order to clarify the mechanism and the influence of the initial charge state and target atomic parameters for the formation of L-shell multiple ionization state of Arq+ ions produced by the collisions near the Bohr velocity, the k-shell x-ray emission of Ar is measured for 1.2 MeV Arq+(q=4, 6, 8, 9, 11, 12) ions impacting on V target and 3 MeV Ar11+ ions interacting with selected targets (Z2 = 23, 26, 27, 28, 29, 30). It is found that the measured Ar Kα and Kβ x-ray energies shift to the high energy side, and the relative intensity ratios of Kβ/Kα are enlarged than the atomic data, owing to the presence of out-shell multiple vacancies. The multiple ionization is almost independence of the projectile charge state, but is diminished with increasing target atomic number.
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Cermak P, Knotek P, Ruleova P, Holy V, Palka K, Kucek V, Benes L, Navratil J, Drasar C. High power factor and mobility of single crystals of Bi2Se3 induced by Mo doping. J SOLID STATE CHEM 2019. [DOI: 10.1016/j.jssc.2019.07.045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Jnawali G, Linser S, Shojaei IA, Pournia S, Jackson HE, Smith LM, Need RF, Wilson SD. Revealing Optical Transitions and Carrier Recombination Dynamics within the Bulk Band Structure of Bi 2Se 3. NANO LETTERS 2018; 18:5875-5884. [PMID: 30106301 DOI: 10.1021/acs.nanolett.8b02577] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Bismuth selenide (Bi2Se3) is a prototypical 3D topological insulator whose Dirac surface states have been extensively studied theoretically and experimentally. Surprisingly little, however, is known about the energetics and dynamics of electrons and holes within the bulk band structure of the semiconductor. We use mid-infrared femtosecond transient reflectance measurements on a single nanoflake to study the ultrafast thermalization and recombination dynamics of photoexcited electrons and holes within the extended bulk band structure over a wide energy range (0.3 to 1.2 eV). Theoretical modeling of the reflectivity spectral line shapes at 10 K demonstrates that the electrons and holes are photoexcited within a dense and cold electron gas with a Fermi level positioned well above the bottom of the lowest conduction band. Direct optical transitions from the first and the second spin-orbit split valence bands to the Fermi level above the lowest conduction band minimum are identified. The photoexcited carriers thermalize rapidly to the lattice temperature within a couple of picoseconds due to optical phonon emission and scattering with the cold electron gas. The minority carrier holes recombine with the dense electron gas within 150 ps at 10 K and 50 ps at 300 K. Such knowledge of interaction of electrons and holes within the bulk band structure provides a foundation for understanding how such states interact dynamically with the topologically protected Dirac surface states.
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Affiliation(s)
- Giriraj Jnawali
- Department of Physics , University of Cincinnati , Cincinnati , Ohio 45221 , United States
| | - Samuel Linser
- Department of Physics , University of Cincinnati , Cincinnati , Ohio 45221 , United States
| | - Iraj Abbasian Shojaei
- Department of Physics , University of Cincinnati , Cincinnati , Ohio 45221 , United States
| | - Seyyedesadaf Pournia
- Department of Physics , University of Cincinnati , Cincinnati , Ohio 45221 , United States
| | - Howard E Jackson
- Department of Physics , University of Cincinnati , Cincinnati , Ohio 45221 , United States
| | - Leigh M Smith
- Department of Physics , University of Cincinnati , Cincinnati , Ohio 45221 , United States
| | - Ryan F Need
- Materials Department , University of California , Santa Barbara , California 93106 , United States
| | - Stephen D Wilson
- Materials Department , University of California , Santa Barbara , California 93106 , United States
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