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Hong S, Kim D, Kim J, Park J, Rho S, Huh J, Lee Y, Jeong K, Cho M. Enhanced Photocharacteristics by Fermi Level Modulating in Sb 2 Te 3 /Bi 2 Se 3 Topological Insulator p-n Junction. Adv Sci (Weinh) 2024; 11:e2307509. [PMID: 38161227 PMCID: PMC10953576 DOI: 10.1002/advs.202307509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/13/2023] [Indexed: 01/03/2024]
Abstract
Topological insulators have recently received attention in optoelectronic devices because of their high mobility and broadband absorption resulting from their topological surface states. In particular, theoretical and experimental studies have emerged that can improve the spin generation efficiency in a topological insulator-based p-n junction structure called a TPNJ, drawing attention in optospintronics. Recently, research on implementing the TPNJ structure is conducted; however, studies on the device characteristics of the TPNJ structure are still insufficient. In this study, the TPNJ structure is effectively implemented without intermixing by controlling the annealing temperature, and the photocharacteristics appearing in the TPNJ structure are investigated using a cross-pattern that can compare the characteristics in a single device. Enhanced photo characteristics are observed for the TPNJ structure. An optical pump Terahertz probe and a physical property measurement system are used to confirm the cause of improved photoresponsivity. Consequently, the photocharacteristics are improved owing to the change in the absorption mechanism and surface transport channel caused by the Fermi level shift in the TPNJ structure.
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Affiliation(s)
- Seok‐Bo Hong
- Department of PhysicsYonsei University50 Yonsei‐roSeoul03722Republic of Korea
| | - Dajung Kim
- Department of PhysicsYonsei University50 Yonsei‐roSeoul03722Republic of Korea
| | - Jonghoon Kim
- Department of PhysicsYonsei University50 Yonsei‐roSeoul03722Republic of Korea
| | - Jaehan Park
- Department of PhysicsYonsei University50 Yonsei‐roSeoul03722Republic of Korea
| | - Seungwon Rho
- Department of PhysicsYonsei University50 Yonsei‐roSeoul03722Republic of Korea
| | - Jaeseok Huh
- Department of PhysicsYonsei University50 Yonsei‐roSeoul03722Republic of Korea
| | - Youngmin Lee
- Department of PhysicsYonsei University50 Yonsei‐roSeoul03722Republic of Korea
| | - Kwangsik Jeong
- Division of Physics and Semiconductor ScienceDongguk UniversitySeoul04620Republic of Korea
| | - Mann‐Ho Cho
- Department of PhysicsYonsei University50 Yonsei‐roSeoul03722Republic of Korea
- Department of System Semiconductor EngineeringYonsei University50 Yonsei‐roSeoul03722Republic of Korea
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2
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Connelly BC, Taylor PJ, de Coster GJ. Emergence of threefold symmetric helical photocurrents in epitaxial low twinned Bi 2Se 3. Proc Natl Acad Sci U S A 2024; 121:e2307425121. [PMID: 38271339 PMCID: PMC10835140 DOI: 10.1073/pnas.2307425121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 11/29/2023] [Indexed: 01/27/2024] Open
Abstract
We present evidence of a strong circular photon drag effect (PDE) in topological insulators (TIs) through the observation of helicity-dependent topological photocurrents with threefold rotational symmetry using THz spectroscopy in epitaxially-grown Bi2Se3 with reduced crystallographic twinning. We establish how twinned domains introduce competing nonlinear optical (NLO) responses inherent to the crystal structure that obscure geometry-sensitive optical processes through the introduction of a spurious mirror symmetry. Minimizing the twinning defect reveals strong NLO response currents whose magnitude and direction depend on the alignment of the excitation to the crystal axes and follow the threefold rotational symmetry of the crystal. Notably, photocurrents arising from helical light reverse direction for left/right circular polarizations and maintain a strong azimuthal dependence-a result uniquely attributable to the circular PDE, where the photon momentum acts as an applied in-plane field stationary in the laboratory frame. Our results demonstrate new levels of control over the magnitude and direction of photocurrents in TIs and that the study of single-domain films is crucial to reveal hidden phenomena that couple topological order and crystal symmetries.
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Affiliation(s)
- Blair C. Connelly
- U.S. Army Combat Capabilities Development Command Army Research Laboratory, Adelphi, MD20783
| | - Patrick J. Taylor
- U.S. Army Combat Capabilities Development Command Army Research Laboratory, Adelphi, MD20783
| | - George J. de Coster
- U.S. Army Combat Capabilities Development Command Army Research Laboratory, Adelphi, MD20783
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3
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Marchenkov VV, Lukoyanov AV, Baidak ST, Perevalova AN, Fominykh BM, Naumov SV, Marchenkova EB. Electronic Structure and Transport Properties of Bi 2Te 3 and Bi 2Se 3 Single Crystals. Micromachines (Basel) 2023; 14:1888. [PMID: 37893325 PMCID: PMC10609277 DOI: 10.3390/mi14101888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/21/2023] [Accepted: 09/28/2023] [Indexed: 10/29/2023]
Abstract
The electrical resistivity and the Hall effect of topological insulator Bi2Te3 and Bi2Se3 single crystals were studied in the temperature range from 4.2 to 300 K and in magnetic fields up to 10 T. Theoretical calculations of the electronic structure of these compounds were carried out in density functional approach, taking into account spin-orbit coupling and crystal structure data for temperatures of 5, 50 and 300 K. A clear correlation was found between the density of electronic states at the Fermi level and the current carrier concentration. In the case of Bi2Te3, the density of states at the Fermi level and the current carrier concentration increase with increasing temperature, from 0.296 states eV-1 cell-1 (5 K) to 0.307 states eV-1 cell-1 (300 K) and from 0.9 × 1019 cm-3 (5 K) to 2.6 × 1019 cm-3 (300 K), respectively. On the contrary, in the case of Bi2Se3, the density of states decreases with increasing temperature, from 0.201 states eV-1 cell-1 (5 K) to 0.198 states eV-1 cell-1 (300 K), and, as a consequence, the charge carrier concentration also decreases from 2.94 × 1019 cm-3 (5 K) to 2.81 × 1019 cm-3 (300 K).
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Affiliation(s)
- Vyacheslav V. Marchenkov
- M.N. Mikheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620108 Ekaterinburg, Russia; (V.V.M.); (S.T.B.); (A.N.P.); (B.M.F.); (S.V.N.); (E.B.M.)
- Institute of Physics and Technology, Ural Federal University Named after the First President of Russia B.N. Yeltsin, 620002 Ekaterinburg, Russia
| | - Alexey V. Lukoyanov
- M.N. Mikheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620108 Ekaterinburg, Russia; (V.V.M.); (S.T.B.); (A.N.P.); (B.M.F.); (S.V.N.); (E.B.M.)
- Institute of Physics and Technology, Ural Federal University Named after the First President of Russia B.N. Yeltsin, 620002 Ekaterinburg, Russia
| | - Semyon T. Baidak
- M.N. Mikheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620108 Ekaterinburg, Russia; (V.V.M.); (S.T.B.); (A.N.P.); (B.M.F.); (S.V.N.); (E.B.M.)
- Institute of Physics and Technology, Ural Federal University Named after the First President of Russia B.N. Yeltsin, 620002 Ekaterinburg, Russia
| | - Alexandra N. Perevalova
- M.N. Mikheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620108 Ekaterinburg, Russia; (V.V.M.); (S.T.B.); (A.N.P.); (B.M.F.); (S.V.N.); (E.B.M.)
| | - Bogdan M. Fominykh
- M.N. Mikheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620108 Ekaterinburg, Russia; (V.V.M.); (S.T.B.); (A.N.P.); (B.M.F.); (S.V.N.); (E.B.M.)
- Institute of Physics and Technology, Ural Federal University Named after the First President of Russia B.N. Yeltsin, 620002 Ekaterinburg, Russia
| | - Sergey V. Naumov
- M.N. Mikheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620108 Ekaterinburg, Russia; (V.V.M.); (S.T.B.); (A.N.P.); (B.M.F.); (S.V.N.); (E.B.M.)
| | - Elena B. Marchenkova
- M.N. Mikheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620108 Ekaterinburg, Russia; (V.V.M.); (S.T.B.); (A.N.P.); (B.M.F.); (S.V.N.); (E.B.M.)
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Zou Z, Yu Z, Chen C, Wang Q, Zhu K, Ye K, Wang G, Cao D, Yan J. High-Performance Alkali Metal Ion Storage in Bi 2Se 3 Enabled by Suppression of Polyselenide Shuttling Through Intrinsic Sb-Substitution Engineering. ACS Nano 2023. [PMID: 37428997 DOI: 10.1021/acsnano.3c03381] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
Bismuth selenide holds great promise as a kind of conversion-alloying-type anode material for alkali metal ion storage because of its layered structure with large interlayer spacing and high theoretical specific capacity. Nonetheless, its commercial development has been significantly hammered by the poor kinetics, severe pulverization, and polyselenide shuttle during the charge/discharge process. Herein, Sb-substitution and carbon encapsulation strategies are simultaneously employed to synthesize SbxBi2-xSe3 nanoparticles decorated on Ti3C2Tx MXene with encapsulation of N-doped carbon (SbxBi2-xSe3/MX⊂NC) as anodes for alkali metal ion storage. The superb electrochemical performances could be assigned to the cationic displacement of Sb3+ that effectively inhibits the shuttling effect of soluble polyselenides and the confinement engineering that alleviates the volume change during the sodiation/desodiation process. When used as anodes for sodium- and lithium-ion batteries, the Sb0.4Bi1.6Se3/MX⊂NC composite exhibits superior electrochemical performances. This work offers valuable guidance to suppress the shuttling of polyselenides/polysulfides in high-performance alkali metal ion batteries with conversion/alloying-type transition metal sulfide/selenide anode materials.
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Affiliation(s)
- Zhengguang Zou
- College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
| | - Zhiqi Yu
- College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
| | - Chi Chen
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, and Xiamen Institute of Rare Earth Materials, Haixi Institute, Chinese Academy of Sciences, Xiamen 361021, China
| | - Qian Wang
- College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
| | - Kai Zhu
- College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
| | - Ke Ye
- College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
| | - Guiling Wang
- College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
| | - Dianxue Cao
- College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
| | - Jun Yan
- College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
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5
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Yuan Z, Zhao X, Wang C, Hang S, Li M, Liu Y. Exploring Material Properties and Device Output Performance of a Miniaturized Flexible Thermoelectric Generator Using Scalable Synthesis of Bi 2Se 3 Nanoflakes. Nanomaterials (Basel) 2023; 13:1937. [PMID: 37446453 DOI: 10.3390/nano13131937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/09/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023]
Abstract
Environmental heat-to-electric energy conversion presents a promising solution for powering sensors in wearable and portable devices. However, the availability of near-room temperature thermoelectric (TE) materials is highly limited, posing a significant challenge in this field. Bi2Se3, as a room-temperature TE material, has attracted much attention. Here, we demonstrate a large-scale synthesis of Bi2Se3 nanoflakes used for the microflexible TE generator. A high-performance micro-TE generator module, utilizing a flexible printed circuit, has been designed and fabricated through the process of screen printing. The TE generator configuration comprises five pairs of PN TE legs. The p-type TE leg utilizes commercially available Sb2Te3 powder, while the n-type TE leg employs Bi2Se3 nanoflakes synthesized in this study. For comparative purposes, we also incorporate commercially available Bi2Se3 powder as an alternative n-type TE leg. The optimal performance of the single-layer microflexible TE generator, employing Bi2Se3 nanoflakes as the active material, is achieved when operating at a temperature differential of 109.5 K, the open-circuit voltage (VOC) is 0.11 V, the short circuit current (ISC) is 0.34 mA, and the maximum output power (PMAX) is 9.5 μW, much higher than the generator consisting of commercial Bi2Se3 powder, which is expected to provide an energy supply for flexible electronic devices.
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Affiliation(s)
- Zicheng Yuan
- Reactor Engineering Sub-Institute, Nuclear Power Institute of China, Chengdu 610213, China
| | - Xueke Zhao
- School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450052, China
| | - Canhui Wang
- Reactor Engineering Sub-Institute, Nuclear Power Institute of China, Chengdu 610213, China
| | - Shuang Hang
- Inter-University Institute for High Energies, Université Libre de Bruxelles, 1050 Brussels, Belgium
| | - Mengyao Li
- Inter-University Institute for High Energies, Université Libre de Bruxelles, 1050 Brussels, Belgium
| | - Yu Liu
- School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, China
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6
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Huang Z, Luo Z, Deng Z, Yang M, Gao W, Yao J, Zhao Y, Dong H, Zheng Z, Li J. Integration of Self-Passivated Topological Electrodes for Advanced 2D Optoelectronic Devices. Small Methods 2023; 7:e2201571. [PMID: 36932942 DOI: 10.1002/smtd.202201571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 02/20/2023] [Indexed: 06/09/2023]
Abstract
With the rapid development of two-dimensional semiconductor technology, the inevitable chemical disorder at a typical metal-semiconductor interface has become an increasingly serious problem that degrades the performance of 2D semiconductor optoelectronic devices. Herein, defect-free van der Waals contacts have been achieved by utilizing topological Bi2 Se3 as the electrodes. Such clean and atomically sharp contacts avoid the consumption of photogenerated carriers at the interface, enabling a markedly boosted sensitivity as compared to counterpart devices with directly deposited metal electrodes. Typically, the device with 2D WSe2 channel realizes a high responsivity of 20.5 A W-1 , an excellent detectivity of 2.18 × 1012 Jones, and a fast rise/decay time of 41.66/38.81 ms. Furthermore, high-resolution visible-light imaging capability of the WSe2 device is demonstrated, indicating its promising application prospect in future optoelectronic systems. More inspiringly, the topological electrodes are universally applicable to other 2D semiconductor channels, including WS2 and InSe, suggesting its broad applicability. These results open fascinating opportunities for the development of high-performance electronics and optoelectronics.
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Affiliation(s)
- Zihao Huang
- Guangdong Provincial Key Laboratory of Information Photonics Technology, School of Materials and Energy, Guangdong University of Technology, Guangzhou, Guangdong, 510006, P. R. China
| | - Zhongtong Luo
- Guangdong Provincial Key Laboratory of Information Photonics Technology, School of Materials and Energy, Guangdong University of Technology, Guangzhou, Guangdong, 510006, P. R. China
| | - Ziwen Deng
- Guangdong Provincial Key Laboratory of Information Photonics Technology, School of Materials and Energy, Guangdong University of Technology, Guangzhou, Guangdong, 510006, P. R. China
| | - Mengmeng Yang
- Guangdong Provincial Key Laboratory of Information Photonics Technology, School of Materials and Energy, Guangdong University of Technology, Guangzhou, Guangdong, 510006, P. R. China
- School of Semiconductor Science and Technology, South China Normal University, Foshan, Guangdong, 528225, P. R. China
| | - Wei Gao
- School of Semiconductor Science and Technology, South China Normal University, Foshan, Guangdong, 528225, P. R. China
| | - Jiandong Yao
- State Key Laboratory of Optoelectronic Materials and Technologies, Nanotechnology Research Center, School of Materials Science & Engineering, Sun Yat-sen University, Guangzhou, Guangdong, 510275, P. R. China
| | - Yu Zhao
- Guangdong Provincial Key Laboratory of Information Photonics Technology, School of Materials and Energy, Guangdong University of Technology, Guangzhou, Guangdong, 510006, P. R. China
| | - Huafeng Dong
- Guangdong Provincial Key Laboratory of Information Photonics Technology, School of Materials and Energy, Guangdong University of Technology, Guangzhou, Guangdong, 510006, P. R. China
| | - Zhaoqiang Zheng
- Guangdong Provincial Key Laboratory of Information Photonics Technology, School of Materials and Energy, Guangdong University of Technology, Guangzhou, Guangdong, 510006, P. R. China
| | - Jingbo Li
- School of Semiconductor Science and Technology, South China Normal University, Foshan, Guangdong, 528225, P. R. China
- Guangdong Provincial Key Laboratory of Chip and Integration Technology, Guangzhou, 510631, P. R. China
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7
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Cho HD, Lee J, Kim DY, Chung SY, Lee JK. Enhanced Photoresponse of High Crystalline Bi 2Se 3 Thin-Films Using Patterned Substrates. ACS Appl Mater Interfaces 2023; 15:22274-22281. [PMID: 37115789 DOI: 10.1021/acsami.3c02501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
High-quality Bi2Se3 thin films with topological insulating properties at room temperature have recently attracted much attention as one of the promising materials for realizing innovative electronic and optoelectronic devices. Here, we report the high crystallinity growth of Bi2Se3 thin films on a patterned sapphire substrate (PSS) by using a vapor-phase transport deposition with minimizing thermal dissociation of Se atoms vaporized in Bi2Se3 powder. This PSS not only reduces the large dislocation of heterogeneously grown Bi2Se3 on a sapphire substrate but also induces enhanced light absorption in the visible to near-infrared (IR) ranges compared to Bi2Se3 on planar sapphire substrates. Thus, the Bi2Se3 thin film laterally grown on the PSS reveals uniform surface properties and high crystallinity in the rhombohedral lattice phase with a full width at half maximum of 0.06° for the XRD (003) peak. Also, the photoresponse of the fabricated IR conversion device using Bi2Se3/PSS heterostructure exhibits excellent performance and high reliability with no degradation after continuous switching. As a result, the device constructed with the Bi2Se3/PSS exhibits one order of magnitude higher NIR induced-photocurrent and 1-2 orders of magnitude faster photo-switching than that with Bi2Se3/Al2O3. Such an enhancement in the device performance of Bi2Se3/PSS is confirmed by the increased absorption spectra in visible and NIR ranges and the improved light absorption distribution.
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Affiliation(s)
- Hak Dong Cho
- Quantum Functional Semiconductor Research Center, Dongguk University, Seoul 04620, Korea
| | - Juwon Lee
- Quantum Functional Semiconductor Research Center, Dongguk University, Seoul 04620, Korea
| | - Deuk Young Kim
- Quantum Functional Semiconductor Research Center, Dongguk University, Seoul 04620, Korea
- Division of Physics and Semiconductor Science, Dongguk University, Seoul 04620, Korea
| | - Sung Yun Chung
- Division of Energy and Optical Technology Convergence, Cheongju University, Cheongju-si, Chungcheongbuk-do 28503, Korea
| | - Jong-Kwon Lee
- Division of Energy and Optical Technology Convergence, Cheongju University, Cheongju-si, Chungcheongbuk-do 28503, Korea
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8
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Gracia-Abad R, Sangiao S, Kumar Chaluvadi S, Orgiani P, Teresa JMD. Ion-Induced Lateral Damage in the Focused Ion Beam Patterning of Topological Insulator Bi 2Se 3 Thin Films. Materials (Basel) 2023; 16:2244. [PMID: 36984129 PMCID: PMC10051711 DOI: 10.3390/ma16062244] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/03/2023] [Accepted: 03/08/2023] [Indexed: 06/18/2023]
Abstract
Focused Ion Beam patterning has become a widely applied technique in the last few decades in the micro- and nanofabrication of quantum materials, representing an important advantage in terms of resolution and versatility. However, ion irradiation can trigger undesired effects on the target material, most of them related to the damage created by the impinging ions that can severely affect the crystallinity of the sample, compromising the application of Focused Ion Beam to the fabrication of micro- and nanosized systems. We focus here on the case of Bi2Se3, a topological material whose unique properties rely on its crystallinity. In order to study the effects of ion irradiation on the structure of Bi2Se3, we irradiated with Ga+ ions the full width of Hall-bar devices made from thin films of this material, with the purpose of inducing changes in the electrical resistance and characterizing the damage created during the process. The results indicate that a relatively high ion dose is necessary to introduce significant changes in the conduction. This ion dose creates medium-range lateral damage in the structure, manifested through the formation of an amorphous region that can extend laterally up to few hundreds of nanometers beyond the irradiated area. This amorphous material is no longer expected to behave as intrinsic Bi2Se3, indicating a spatial limitation for the devices fabricated through this technique.
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Affiliation(s)
- Rubén Gracia-Abad
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain
- Laboratorio de Microscopías Avanzadas (LMA), Universidad de Zaragoza, 50018 Zaragoza, Spain
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - Soraya Sangiao
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain
- Laboratorio de Microscopías Avanzadas (LMA), Universidad de Zaragoza, 50018 Zaragoza, Spain
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain
| | | | - Pasquale Orgiani
- CNR-IOM, TASC Laboratory in Area Science Park, 34149 Trieste, Italy
| | - José María De Teresa
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain
- Laboratorio de Microscopías Avanzadas (LMA), Universidad de Zaragoza, 50018 Zaragoza, Spain
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain
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Han J, Pang M, Meng D, Qiu J, Wang D. Construction of Bouquet-like Bi 2Se 3/Bi 2O 3@Bi Composites with High Interfacial Charge Separation for the Degradation of Atrazine. Materials (Basel) 2023; 16:1896. [PMID: 36903010 PMCID: PMC10004082 DOI: 10.3390/ma16051896] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 02/21/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Using low-density solar energy in the environment and converting it into chemical energy that can drive the degradation of organic pollutants is considered to be a very promising strategy for solving the problem of environmental pollution. The efficacy of photocatalytic destruction of organic contaminants is nonetheless constrained by the high composite rate of photogenic carriers, insufficient light absorption and utilization impact, and sluggish charge transfer rate. In this work, we created a new type of heterojunction photocatalyst with a spherical Bi2Se3/Bi2O3@Bi core-shell structure and investigated its degrading properties of organic pollutants in the environment. Interestingly, benefiting from the fast electron transfer capability of the Bi0 electron bridge, the charge separation and transfer efficiency between Bi2Se3 and Bi2O3 is greatly improved. In this photocatalyst, Bi2Se3 not only has a photothermal effect to speed up the process of photocatalytic reaction, but also has fast electrical conductivity of topological materials at the surface, which speeds up the transmission efficiency of photogenic carriers. As expected, the removal performance of the Bi2Se3/Bi2O3@Bi photocatalyst to atrazine is 4.2 and 5.7 times higher than that of the original Bi2Se3 and Bi2O3. Meanwhile, the best samples Bi2Se3/Bi2O3@Bi showed 98.7%, 97.8%, 69.4%, 90.6%, 91.2%, 77.2%, 97.7%, and 98.9% removal of ATZ, 2,4-DCP, SMZ, KP, CIP, CBZ, OTC-HCl, and RhB, and 56.8%, 59.1%, 34.6%, 34.5%, 37.1%, 73.9%, and 78.4% mineralization. Through characterization such as XPS and electrochemical workstations, it is proved that the photocatalytic properties of Bi2Se3/Bi2O3@Bi catalysts are far superior to other materials, and a suitable photocatalytic mechanism is proposed. A novel form of bismuth-based compound photocatalyst is anticipated to be produced as a result of this research in order to address the increasingly critical problem of environmental water pollution in addition to presenting fresh avenues for the creation of adaptable nanomaterials for additional environmental applications.
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Affiliation(s)
- Juncheng Han
- School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
| | - Menghan Pang
- School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
| | - Donghuan Meng
- School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
| | - Jianrong Qiu
- School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
| | - Dongbo Wang
- School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
- Guangxi Universities Key Laboratory of Environmental Protection, Guangxi University, Nanning 530004, China
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10
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Hennighausen Z, Moon J, McCreary KM, Li CH, van 't Erve OMJ, Jonker BT. Interlayer Exciton-Phonon Bound State in Bi 2Se 3/Monolayer WS 2 van der Waals Heterostructures. ACS Nano 2023; 17:2529-2536. [PMID: 36646115 DOI: 10.1021/acsnano.2c10313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The ability to assemble layers of two-dimensional (2D) materials to form permutations of van der Waals heterostructures provides significant opportunities in materials design and synthesis. Interlayer interactions can enable desired properties and functionality, and understanding such interactions is essential to that end. Here we report formation of interlayer exciton-phonon bound states in Bi2Se3/WS2 heterostructures, where the Bi2Se3 A1(3) surface phonon, a mode particularly susceptible to electron-phonon coupling, is imprinted onto the excitonic emission of the WS2. The exciton-phonon bound state (or exciton-phonon quasiparticle) presents itself as evenly separated peaks superposed on the WS2 excitonic photoluminescence spectrum, whose periodic spacing corresponds to the A1(3) surface phonon energy. Low-temperature polarized Raman spectroscopy of Bi2Se3 reveals intense surface phonons and local symmetry breaking that allows the A1(3) surface phonon to manifest in otherwise forbidden scattering geometries. Our work advances knowledge of the complex interlayer van der Waals interactions and facilitates technologies that combine the distinctive transport and optical properties from separate materials into one device for possible spintronics, valleytronics, and quantum computing applications.
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Affiliation(s)
- Zachariah Hennighausen
- NRC Postdoc at the Materials Science and Technology Division, Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Jisoo Moon
- NRC Postdoc at the Materials Science and Technology Division, Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Kathleen M McCreary
- Materials Science and Technology Division, Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Connie H Li
- Materials Science and Technology Division, Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Olaf M J van 't Erve
- Materials Science and Technology Division, Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Berend T Jonker
- Materials Science and Technology Division, Naval Research Laboratory, Washington, D.C. 20375, United States
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11
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Kim D, Yang C, Park YD. Towards More Accurate Determination of the Thermoelectric Properties of Bi 2Se 3 Epifilms by Suspension via Nanomachining Techniques. Sensors (Basel) 2022; 22:8042. [PMID: 36298391 PMCID: PMC9609336 DOI: 10.3390/s22208042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 10/12/2022] [Accepted: 10/19/2022] [Indexed: 06/16/2023]
Abstract
We report on the characterization of the thermoelectric properties of Bi2Se3 epifilms. MBE-grown Bi2Se3 films on GaAs (111) A are nanomachined with integrated Pt elements serving as local joule heaters, thermometers, and voltage probes. We suspended a 4 µm × 120 µm Bi2Se3 by nanomachining techniques. Specifically, we selectively etched GaAs buffer/substrate layers by citric acid solution followed by a critical point drying method. We found that the self-heating 3ω method is an appropriate technique for the accurate measurement of the thermal conductivity of suspended Bi2Se3. The measured thermoelectric properties of 200 nm thick Bi2Se3 at room temperature were κ=1.95 W/m K, S=−102.8 μV/K, σ = 75,581 S/m and the figure of merit was ZT=0.12. The study introduces a method to measure thermal conductivity accurately by suspending thin films.
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Affiliation(s)
- Donguk Kim
- Department of Physics & Astronomy, Seoul National University, Seoul 08858, Korea
| | - Chanuk Yang
- Department of Physics, Research Institute of Physics and Chemistry, Jeonbuk National University, Jeonju 54896, Korea
| | - Yun Daniel Park
- Department of Physics & Astronomy, Seoul National University, Seoul 08858, Korea
- Institute of Applied Physics, Seoul National University, Seoul 08858, Korea
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12
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Salvato M, Crescenzi MD, Scagliotti M, Castrucci P, Boninelli S, Caruso GM, Liu Y, Mikkelsen A, Timm R, Nahas S, Black-Schaffer A, Kunakova G, Andzane J, Erts D, Bauch T, Lombardi F. Nanometric Moiré Stripes on the Surface of Bi 2Se 3 Topological Insulator. ACS Nano 2022; 16:13860-13868. [PMID: 36098662 PMCID: PMC9527797 DOI: 10.1021/acsnano.2c02515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 09/07/2022] [Indexed: 06/15/2023]
Abstract
Mismatch between adjacent atomic layers in low-dimensional materials, generating moiré patterns, has recently emerged as a suitable method to tune electronic properties by inducing strong electron correlations and generating novel phenomena. Beyond graphene, van der Waals structures such as three-dimensional (3D) topological insulators (TIs) appear as ideal candidates for the study of these phenomena due to the weak coupling between layers. Here we discover and investigate the origin of 1D moiré stripes on the surface of Bi2Se3 TI thin films and nanobelts. Scanning tunneling microscopy and high-resolution transmission electron microscopy reveal a unidirectional strained top layer, in the range 14-25%, with respect to the relaxed bulk structure, which cannot be ascribed to the mismatch with the substrate lattice but rather to strain induced by a specific growth mechanism. The 1D stripes are characterized by a spatial modulation of the local density of states, which is strongly enhanced compared to the bulk system. Density functional theory calculations confirm the experimental findings, showing that the TI surface Dirac cone is preserved in the 1D moiré stripes, as expected from the topology, though with a heavily renormalized Fermi velocity that also changes between the top and valley of the stripes. The strongly enhanced density of surface states in the TI 1D moiré superstructure can be instrumental in promoting strong correlations in the topological surface states, which can be responsible for surface magnetism and topological superconductivity.
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Affiliation(s)
- Matteo Salvato
- Dipartimento
di Fisica and INFN, Università di
Roma “Tor Vergata”, 00133 Roma, Italy
| | - Maurizio De Crescenzi
- Dipartimento
di Fisica and INFN, Università di
Roma “Tor Vergata”, 00133 Roma, Italy
| | - Mattia Scagliotti
- Dipartimento
di Fisica and INFN, Università di
Roma “Tor Vergata”, 00133 Roma, Italy
| | - Paola Castrucci
- Dipartimento
di Fisica and INFN, Università di
Roma “Tor Vergata”, 00133 Roma, Italy
| | | | | | - Yi Liu
- Division
of Synchrotron Radiation Research, Department of Physics and NanoLund, Lund University, 221 00 Lund, Sweden
| | - Anders Mikkelsen
- Division
of Synchrotron Radiation Research, Department of Physics and NanoLund, Lund University, 221 00 Lund, Sweden
| | - Rainer Timm
- Division
of Synchrotron Radiation Research, Department of Physics and NanoLund, Lund University, 221 00 Lund, Sweden
| | - Suhas Nahas
- Department
of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden
| | - Annica Black-Schaffer
- Department
of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden
| | - Gunta Kunakova
- Institute
of Chemical Physics, University of Latvia, LV-1586 Riga, Latvia
- Quantum Device
Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, 41296 Goteborg, Sweden
| | - Jana Andzane
- Institute
of Chemical Physics, University of Latvia, LV-1586 Riga, Latvia
| | - Donats Erts
- Institute
of Chemical Physics, University of Latvia, LV-1586 Riga, Latvia
| | - Thilo Bauch
- Quantum Device
Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, 41296 Goteborg, Sweden
| | - Floriana Lombardi
- Quantum Device
Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, 41296 Goteborg, Sweden
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13
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Liu Y, Acuna W, Zhang H, Ho DQ, Hu R, Wang Z, Janotti A, Bryant G, Davydov AV, Zide JMO, Law S. Bi 2Se 3 Growth on (001) GaAs Substrates for Terahertz Integrated Systems. ACS Appl Mater Interfaces 2022; 14:42683-42691. [PMID: 36074957 DOI: 10.1021/acsami.2c11135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Terahertz (THz) technologies have been of interest for many years due to the variety of applications including gas sensing, nonionizing imaging of biological systems, security and defense, and so forth. To date, scientists have used different classes of materials to perform different THz functions. However, to assemble an on-chip THz integrated system, we must understand how to integrate these different materials. Here, we explore the growth of Bi2Se3, a topological insulator material that could serve as a plasmonic waveguide in THz integrated devices, on technologically important GaAs(001) substrates. We explore surface treatments and find that an atomically smooth GaAs surface is critical to achieving high-quality Bi2Se3 films despite the relatively weak film/substrate interaction. Calculations indicate that the Bi2Se3/GaAs interface is likely selenium-terminated and shows no evidence of chemical bonding between the Bi2Se3 and the substrate. These results are a guide for integrating van der Waals materials with conventional semiconductor substrates and serve as the first steps toward achieving an on-chip THz integrated system.
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Affiliation(s)
- Yongchen Liu
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Wilder Acuna
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Huairuo Zhang
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
- Theiss Research, Inc., La Jolla, California 92037, United States
| | - Dai Q Ho
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Ruiqi Hu
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Zhengtianye Wang
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Anderson Janotti
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Garnett Bryant
- Nanoscale Device Characterization Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Albert V Davydov
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Joshua M O Zide
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Stephanie Law
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
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14
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Scheitz S, Glier TE, Nweze C, van Heek M, Moch I, Zierold R, Blick R, Huse N, Rübhausen M. Carrier Injection Observed by Interface-Enhanced Raman Scattering from Topological Insulators on Gold Substrates. ACS Appl Mater Interfaces 2022; 14:32625-32633. [PMID: 35816728 DOI: 10.1021/acsami.2c04380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The electron-phonon interaction at the interface between topological insulator (TI), namely, Bi2Se3 and Bi2Te3 two-dimensional (2D) nanoflakes, to a gold substrate as a function of TI flake thickness is studied by means of Raman scattering. We reveal the presence of interface-enhanced Raman scattering and a strong phonon renormalization induced by carriers injected from the gold substrate to the topological surface in contact. We derive the change of the electron-phonon coupling showing a nearly linear behavior as a function of layer thickness. The strongly nonlinear change of the Raman scattering cross section as a function of flake thickness can be associated with band bending effects at the metal-TI interface. Our results provide spectroscopic evidence for a strongly modified band structure in the first few quintuple layers of Bi2Se3 and Bi2Te3 in contact with gold.
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Affiliation(s)
- Sarah Scheitz
- Institut für Nanostruktur- und Festkörperphysik, Center for Free Electron Laser Science (CFEL), Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Tomke Eva Glier
- Institut für Nanostruktur- und Festkörperphysik, Center for Free Electron Laser Science (CFEL), Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Christian Nweze
- Institut für Nanostruktur- und Festkörperphysik, Center for Free Electron Laser Science (CFEL), Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Malte van Heek
- Institut für Nanostruktur- und Festkörperphysik, Center for Free Electron Laser Science (CFEL), Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Isa Moch
- Institut für Nanostruktur- und Festkörperphysik, Center for Free Electron Laser Science (CFEL), Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Robert Zierold
- Institut für Nanostruktur- und Festkörperphysik, Center for Hybrid Nanostructures (CHyN), Universität Hamburg, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Robert Blick
- Institut für Nanostruktur- und Festkörperphysik, Center for Hybrid Nanostructures (CHyN), Universität Hamburg, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Nils Huse
- Institut für Nanostruktur- und Festkörperphysik, Center for Free Electron Laser Science (CFEL), Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Michael Rübhausen
- Institut für Nanostruktur- und Festkörperphysik, Center for Free Electron Laser Science (CFEL), Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
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15
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Li CH, Moon J, van 't Erve OMJ, Wickramaratne D, Cobas ED, Johannes MD, Jonker BT. Spin-Sensitive Epitaxial In 2Se 3 Tunnel Barrier in In 2Se 3/Bi 2Se 3 Topological van der Waals Heterostructure. ACS Appl Mater Interfaces 2022; 14:34093-34100. [PMID: 35820066 DOI: 10.1021/acsami.2c08053] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Current-generated spin arising from spin-momentum locking in topological insulator (TI) surface states has been shown to switch the magnetization of an adjacent ferromagnet (FM) via spin-orbit torque (SOT) with a much higher efficiency than heavy metals. However, in such FM/TI heterostructures, most of the current is shunted through the FM metal due to its lower resistance, and recent calculations have also shown that topological surface states can be significantly impacted when interfaced with an FM metal such as Ni and Co. Hence, placing an insulating layer between the TI and FM will not only prevent current shunting, therefore minimizing overall power consumption, but may also help preserve the topological surface states at the interface. Here, we report the van der Waals epitaxial growth of β-phase In2Se3 on Bi2Se3 by molecular beam epitaxy and demonstrate its spin sensitivity by the electrical detection of current-generated spin in Bi2Se3 surface states using a Fe/In2Se3 detector contact. Our density functional calculations further confirm that the linear dispersion and spin texture of the Bi2Se3 surface states are indeed preserved at the In2Se3/Bi2Se3 interface. This demonstration of an epitaxial crystalline spin-sensitive barrier that can be grown directly on Bi2Se3, and verification that it preserves the topological surface state, is electrically insulating and spin-sensitive, is an important step toward minimizing overall power consumption in SOT switching in TI/FM heterostructures in fully epitaxial topological spintronic devices.
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Affiliation(s)
- Connie H Li
- Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375, United States
| | - Jisoo Moon
- Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375, United States
- National Research Council, Washington, DC 20001, United States
| | - Olaf M J van 't Erve
- Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375, United States
| | - Darshana Wickramaratne
- Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375, United States
| | - Enrique D Cobas
- Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375, United States
| | - Michelle D Johannes
- Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375, United States
| | - Berend T Jonker
- Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375, United States
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16
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Yu M, Fang C, Han J, Liu W, Gao S, Huang K. Construction of Bi 2O 2Se/Bi 2Se 3 Van Der Waals Heterostructures for Self-Powered and Broadband Photodetectors. ACS Appl Mater Interfaces 2022; 14:13507-13515. [PMID: 35258932 DOI: 10.1021/acsami.2c00616] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Due to its superior carrier mobility and high air stability, the emerging two-dimensional (2D) layered bismuth oxyselenide (Bi2O2Se) nanosheets have attracted extensive attention, showing great potential for applications in the electronic and optoelectronic fields. However, a high mobility easily leads to a high dark current, seriously restricting optoelectronic applications, especially in the field of photodetectors. In this paper, we report a high-quality Van der Waals (vdWs) Bi2O2Se/Bi2Se3 heterostructure on a fluorophlogopite substrate, exhibiting excellent photodiode characteristics. By means of the effective separation of photogenerated electrons and holes by a junction barrier at the interface, the current on/off ratio is up to about 3 × 103 under 532 nm laser illumination with zero bias. In addition, the photodetector not only achieves a fast response speed of 41 ms but also has a broadband photoresponse from 532 to 1450 nm (visible-NIR). Additionally, the responsivity can reach 0.29 A/W, and the external quantum efficiency exceeds 69% when the device operates in the reverse bias condition. The results indicate that the Bi2O2Se/Bi2Se3 vdWs heterostructure has great potential for self-powered, broadband, and fast photodetection applications.
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Affiliation(s)
- Ming Yu
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan, Hunan 411105, P. R. China
| | - Chaocheng Fang
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan, Hunan 411105, P. R. China
| | - Jianfu Han
- Hunan Institute of Advanced Sensing and Information Technology, Xiangtan University, Xiangtan, Hunan 411105, P. R. China
| | - Wenliang Liu
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan, Hunan 411105, P. R. China
| | - Shengmei Gao
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan, Hunan 411105, P. R. China
| | - Kai Huang
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan, Hunan 411105, P. R. China
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17
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Wang CC, Lin PT, Shieu FS, Shih HC. Enhanced Photocurrent of the Ag Interfaced Topological Insulator Bi 2Se 3 under UV- and Visible-Light Radiations. Nanomaterials (Basel) 2021; 11:nano11123353. [PMID: 34947704 PMCID: PMC8705254 DOI: 10.3390/nano11123353] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/05/2021] [Accepted: 12/08/2021] [Indexed: 11/16/2022]
Abstract
Bi2Se3 is a topological quantum material that is used in photodetectors, owing to its narrow bandgap, conductive surface, and insulating bulk. In this work, Ag@Bi2Se3 nanoplatelets were synthesized on Al2O3(100) substrates in a two-step process of thermal evaporation and magnetron sputtering. X-ray diffractometer (XRD), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, and x-ray photoelectron spectroscopy (XPS) revealed that all samples had the typical rhombohedral Bi2Se3. Field-emission scanning electron microscopy (FESEM)-energy dispersive x-ray spectroscopy (EDS), XPS, and HRTEM confirmed the presence of the precipitated Ag. The optical absorptance of Bi2Se3 nanoplatelets in UV-visible range decreased with the Ag contents. Results of photocurrent measurements under zero-bias conditions revealed that the deposited Ag affected photosensitivity. A total of 7.1 at.% Ag was associated with approximately 4.25 and 4.57 times higher photocurrents under UV and visible light, respectively, than 0 at.% Ag. The photocurrent in Bi2Se3 at 7.1 at.% Ag under visible light was 1.72-folds of that under UV light. This enhanced photocurrent is attributable to the narrow bandgap (~0.35 eV) of Bi2Se3 nanoplatelets, the Schottky field at the interface between Ag and Bi2Se3, the surface plasmon resonance that is caused by Ag, and the highly conductive surface that is formed from Ag and Bi2Se3. This work suggests that the appropriate Ag deposition enhances the photocurrent in, and increases the photosensitivity of, Bi2Se3 nanoplatelets under UV and visible light.
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Affiliation(s)
- Chih-Chiang Wang
- Department of Materials Science and Engineering, National Chung Hsing University, Taichung 40227, Taiwan;
- International Agriculture Center, National Chung Hsing University, Taichung 40227, Taiwan
| | - Pao-Tai Lin
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843, USA;
| | - Fuh-Sheng Shieu
- Department of Materials Science and Engineering, National Chung Hsing University, Taichung 40227, Taiwan;
- Correspondence: (F.-S.S.); (H.-C.S.)
| | - Han-Chang Shih
- Department of Materials Science and Engineering, National Chung Hsing University, Taichung 40227, Taiwan;
- Department of Chemical Engineering and Materials Science, Chinese Culture University, Taipei 11114, Taiwan
- Correspondence: (F.-S.S.); (H.-C.S.)
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18
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Wen D, Dong L, Li K, Du Y, Deng R, Feng J, Zhang H, Wang D. Selenium Vacancy Engineering Using Bi 2Se 3 Nanodots for Boosting Highly Efficient Photonic Hyperthermia. ACS Appl Mater Interfaces 2021; 13:48378-48385. [PMID: 34632756 DOI: 10.1021/acsami.1c13107] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Despite bismuth-based energy conversion nanomaterials having attracted extensive attention for nanomedicine, the nanomaterials suffer from major shortcomings including low tumor accumulation, long internal retention time, and undesirable photothermal conversion efficiency (PCE). To combat these challenges, bovine serum albumin and folic acid co-modified Bi2Se3 nanomedicine with rich selenium vacancies (abbreviated as VSe-BS) was fabricated for the second near-infrared (NIR-II) light-triggered photonic hyperthermia. More importantly, selenium vacancies on the crystal planes (0 1 5) and (0 1 11) of VSe-BS with similar formation energies could be distinctively observed via aberration-corrected scanning transmission electron microscopy images. The defect engineering endows VSe-BS with enhanced conductivity, making VSe-BS possess outstanding PCE (54.1%) in the NIR-II biowindow and desirable photoacoustic imaging performance. Tumor ablation studies indicate that VSe-BS possesses satisfactory therapeutic outcomes triggered by NIR-II light. These findings give rise to inspiration for further broadening the biological applications of defect engineering bismuth-based nanomaterials.
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Affiliation(s)
- Ding Wen
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Lile Dong
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Kai Li
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Yechao Du
- Department of Gastric and Colorectal Surgery, The First Hospital of Jilin University, Changchun 130021, China
| | - Ruiping Deng
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Jing Feng
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Hongjie Zhang
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China
- Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Daguang Wang
- Department of Gastric and Colorectal Surgery, The First Hospital of Jilin University, Changchun 130021, China
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19
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Li P, You Y, Huang K, Luo W. Quantum anomalous Hall effect in Cr 2Ge 2Te 6/Bi 2Se 3/Cr 2Ge 2Te 6heterostructures. J Phys Condens Matter 2021; 33:465003. [PMID: 34433141 DOI: 10.1088/1361-648x/ac2117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
Currently, quantum anomalous Hall (QAH) effect can only be observed at very low temperatures, which severely hinders its utilization from spintronics to quantum computation. Finding or predicting new systems supporting QAH effect at high temperatures remains essential and challenging. This work presents first-principles studies on the proximity effect between Bi2Se3slabs and Cr2Ge2Te6(CGT) layers, reporting that Chern insulators are available in CGT/Bi2Se3/CGT heterostructures. If the sandwiched Bi2Se3slab is 4 quintuple layers (QLs) or thicker, the Chern insulating state is robust against the interfacial stacking manner. If the Bi2Se3slab is only 2 or 3 QLs, the CrBi- and CrH-aligned heterostructures are also Chern insulators, while the CrSe-aligned ones are trivial. The Chern insulators support the Hall conductivityσxy=e2/hand have energy gaps ranging from 3 to 20 meV, implying QAH effect at higher temperatures. An effective model Hamiltonian is introduced to understand the topological phase of the heterostructures.
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Affiliation(s)
- Ping Li
- Key Laboratory of Advanced Electronic Materials and Devices, School of Mathematics and Physics, Anhui Jianzhu University, Hefei, 230601, People's Republic of China
| | - Yuwei You
- Key Laboratory of Advanced Electronic Materials and Devices, School of Mathematics and Physics, Anhui Jianzhu University, Hefei, 230601, People's Republic of China
| | - Kai Huang
- Key Laboratory of Advanced Electronic Materials and Devices, School of Mathematics and Physics, Anhui Jianzhu University, Hefei, 230601, People's Republic of China
| | - Weidong Luo
- Key Laboratory of Artificial Structures and Quantum Control, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
- Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
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20
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Sondors R, Kunakova G, Jasulaneca L, Andzane J, Kauranens E, Bechelany M, Erts D. High-Yield Growth and Tunable Morphology of Bi 2Se 3 Nanoribbons Synthesized on Thermally Dewetted Au. Nanomaterials (Basel) 2021; 11:nano11082020. [PMID: 34443851 PMCID: PMC8401543 DOI: 10.3390/nano11082020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/30/2021] [Accepted: 08/05/2021] [Indexed: 11/16/2022]
Abstract
The yield and morphology (length, width, thickness) of stoichiometric Bi2Se3 nanoribbons grown by physical vapor deposition is studied as a function of the diameters and areal number density of the Au catalyst nanoparticles of mean diameters 8–150 nm formed by dewetting Au layers of thicknesses 1.5–16 nm. The highest yield of the Bi2Se3 nanoribbons is reached when synthesized on dewetted 3 nm thick Au layer (mean diameter of Au nanoparticles ~10 nm) and exceeds the nanoribbon yield obtained in catalyst-free synthesis by almost 50 times. The mean lengths and thicknesses of the Bi2Se3 nanoribbons are directly proportional to the mean diameters of Au catalyst nanoparticles. In contrast, the mean widths of the Bi2Se3 nanoribbons do not show a direct correlation with the Au nanoparticle size as they depend on the contribution ratio of two main growth mechanisms—catalyst-free and vapor–liquid–solid deposition. The Bi2Se3 nanoribbon growth mechanisms in relation to the Au catalyst nanoparticle size and areal number density are discussed. Determined charge transport characteristics confirm the high quality of the synthesized Bi2Se3 nanoribbons, which, together with the high yield and tunable morphology, makes these suitable for application in a variety of nanoscale devices.
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Affiliation(s)
- Raitis Sondors
- Institute of Chemical Physics, University of Latvia, 19 Raina Blvd., LV-1586 Riga, Latvia; (R.S.); (G.K.); (L.J.); (J.A.); (E.K.)
| | - Gunta Kunakova
- Institute of Chemical Physics, University of Latvia, 19 Raina Blvd., LV-1586 Riga, Latvia; (R.S.); (G.K.); (L.J.); (J.A.); (E.K.)
| | - Liga Jasulaneca
- Institute of Chemical Physics, University of Latvia, 19 Raina Blvd., LV-1586 Riga, Latvia; (R.S.); (G.K.); (L.J.); (J.A.); (E.K.)
| | - Jana Andzane
- Institute of Chemical Physics, University of Latvia, 19 Raina Blvd., LV-1586 Riga, Latvia; (R.S.); (G.K.); (L.J.); (J.A.); (E.K.)
| | - Edijs Kauranens
- Institute of Chemical Physics, University of Latvia, 19 Raina Blvd., LV-1586 Riga, Latvia; (R.S.); (G.K.); (L.J.); (J.A.); (E.K.)
| | - Mikhael Bechelany
- Institut Européen des Membranes, IEM-UMR 5635, ENSCM, CNRS, University of Montpellier, Place Eugène Bataillon, 34095 Montpellier, France;
| | - Donats Erts
- Institute of Chemical Physics, University of Latvia, 19 Raina Blvd., LV-1586 Riga, Latvia; (R.S.); (G.K.); (L.J.); (J.A.); (E.K.)
- Faculty of Chemistry, University of Latvia, 19 Raina Blvd., LV-1586 Riga, Latvia
- Correspondence:
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21
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Peng X, Liang H, Dong X, Yang H, Wang X, Qiao L, Li J, Wang C, Han J, Wang Q, Chen G, Xiao W. Epitaxial growth of Bi(110) and Bi 2Se 3thin films on a ferromagnetic insulator substrate of Cr 2Ge 2Te 6. J Phys Condens Matter 2021; 33:415001. [PMID: 34271559 DOI: 10.1088/1361-648x/ac1535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 07/16/2021] [Indexed: 06/13/2023]
Abstract
When a topological insulator (TI) is brought to the proximity of a ferromagnetic insulator (FMI), the breaking of the time-reversal symmetry may give rise to quantum anomalous Hall effect (QAHE). The physical properties of such TI-FMI systems are greatly affected by the interfacial structures of the components. Here, we report the growth and structural properties of Bi(110) and Bi2Se3thin films on a FMI of Cr2Ge2Te6(CGT) substrate by scanning tunneling microscopy. We observed various defects and impurities on the CGT surfaces, which serve as the preferential sites for initial nucleation and epitaxial growth of Bi(110) thin films. The exposure of the as-grown Bi(110) thin films to Se vapor leads to the formation of polycrystalline Bi2Se3thin films with randomly distributed holes. The structure and composition of the as-prepared Bi2Se3thin films were further confirmed by Raman spectroscopy and x-ray photoelectron spectroscopy. Our work shows that the quality of the CGT crystals is vital for the growth of high-quality TIs on CGT substrates for QAHE.
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Affiliation(s)
- Xianglin Peng
- Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement, Ministry of Education, School of Physics, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Hui Liang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Xu Dong
- Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement, Ministry of Education, School of Physics, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Huixia Yang
- Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement, Ministry of Education, School of Physics, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Xiangzhuo Wang
- Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement, Ministry of Education, School of Physics, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Lu Qiao
- Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement, Ministry of Education, School of Physics, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Ji Li
- Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement, Ministry of Education, School of Physics, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Chang Wang
- Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement, Ministry of Education, School of Physics, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Junfeng Han
- Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement, Ministry of Education, School of Physics, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Qinsheng Wang
- Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement, Ministry of Education, School of Physics, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Genfu Chen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan 523808, People's Republic of China
| | - Wende Xiao
- Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement, Ministry of Education, School of Physics, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
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22
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Li M, Zhang Y, Zhang T, Zuo Y, Xiao K, Arbiol J, Llorca J, Liu Y, Cabot A. Enhanced Thermoelectric Performance of n-Type Bi 2Se 3 Nanosheets through Sn Doping. Nanomaterials (Basel) 2021; 11:1827. [PMID: 34361214 DOI: 10.3390/nano11071827] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/03/2021] [Accepted: 07/12/2021] [Indexed: 11/17/2022]
Abstract
The cost-effective conversion of low-grade heat into electricity using thermoelectric devices requires developing alternative materials and material processing technologies able to reduce the currently high device manufacturing costs. In this direction, thermoelectric materials that do not rely on rare or toxic elements such as tellurium or lead need to be produced using high-throughput technologies not involving high temperatures and long processes. Bi2Se3 is an obvious possible Te-free alternative to Bi2Te3 for ambient temperature thermoelectric applications, but its performance is still low for practical applications, and additional efforts toward finding proper dopants are required. Here, we report a scalable method to produce Bi2Se3 nanosheets at low synthesis temperatures. We studied the influence of different dopants on the thermoelectric properties of this material. Among the elements tested, we demonstrated that Sn doping resulted in the best performance. Sn incorporation resulted in a significant improvement to the Bi2Se3 Seebeck coefficient and a reduction in the thermal conductivity in the direction of the hot-press axis, resulting in an overall 60% improvement in the thermoelectric figure of merit of Bi2Se3.
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23
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Wang CC, Shieu FS, Shih HC. Photosensing and Characterizing of the Pristine and In-, Sn-Doped Bi 2Se 3 Nanoplatelets Fabricated by Thermal V-S Process. Nanomaterials (Basel) 2021; 11:nano11051352. [PMID: 34065472 PMCID: PMC8161412 DOI: 10.3390/nano11051352] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/17/2021] [Accepted: 05/18/2021] [Indexed: 12/02/2022]
Abstract
Pristine, and In-, Sn-, and (In, Sn)-doped Bi2Se3 nanoplatelets synthesized on Al2O3(100) substrate by a vapor–solid mechanism in thermal CVD process via at 600 °C under 2 × 10−2 Torr. XRD and HRTEM reveal that In or Sn dopants had no effect on the crystal structure of the synthesized rhombohedral-Bi2Se3. FPA–FTIR reveals that the optical bandgap of doped Bi2Se3 was 26.3%, 34.1%, and 43.7% lower than pristine Bi2Se3. XRD, FESEM–EDS, Raman spectroscopy, and XPS confirm defects (In3+Bi3+), (In3+V0), (Sn4+Bi3+), (V0Bi3+), and (Sn2+Bi3+). Photocurrent that was generated in (In,Sn)-doped Bi2Se3 under UV(8 W) and red (5 W) light revealed stable photocurrents of 5.20 × 10−10 and 0.35 × 10−10 A and high Iphoto/Idark ratios of 30.7 and 52.2. The rise and fall times of the photocurrent under UV light were 4.1 × 10−2 and 6.6 × 10−2 s. Under UV light, (In,Sn)-dopedBi2Se3 had 15.3% longer photocurrent decay time and 22.6% shorter rise time than pristine Bi2Se3, indicating that (In,Sn)-doped Bi2Se3 exhibited good surface conduction and greater photosensitivity. These results suggest that In, Sn, or both dopants enhance photodetection of pristine Bi2Se3 under UV and red light. The findings also suggest that type of defect is a more important factor than optical bandgap in determining photo-detection sensitivity. (In,Sn)-doped Bi2Se3 has greater potential than undoped Bi2Se3 for use in UV and red-light photodetectors.
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Affiliation(s)
- Chih-Chiang Wang
- Department of Materials Science and Engineering, National Chung Hsing University, Taichung 40227, Taiwan;
| | - Fuh-Sheng Shieu
- Department of Materials Science and Engineering, National Chung Hsing University, Taichung 40227, Taiwan;
- Correspondence: (F.-S.S.); (H.C.S.)
| | - Han C. Shih
- Department of Materials Science and Engineering, National Chung Hsing University, Taichung 40227, Taiwan;
- Department of Chemical Engineering and Materials Science, Chinese Culture University, Taipei 11114, Taiwan
- Correspondence: (F.-S.S.); (H.C.S.)
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24
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Hao X, Zhu H, Guo Z, Li H, Gong Y, Chen D. Local insight to the structural phase transition sequence of Bi 2Se 3under quasi-hydrostatic and nonhydrostatic pressure. J Phys Condens Matter 2021; 33:215402. [PMID: 33588383 DOI: 10.1088/1361-648x/abe648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 02/15/2021] [Indexed: 06/12/2023]
Abstract
High-pressure behaviors of Bi2Se3, as one of layered 3D topological insulators, has attracted tremendous interest recent years. However, the phase transition sequence of Bi2Se3remain controversial. In this work, we explore the structural phase sequence of topological insulator Bi2Se3using high-pressure x-ray absorption fine structure (XAFS) spectroscopy under quasi-hydrostatic and nonhydrostatic pressure up to 42 GPa. By examining the XAFS features, we find that the appearance ofC2/cphase of Bi2Se3is strongly dependent on pressure condition,C2/cphase of Bi2Se3only exists under quasi-hydrostatic pressure condition. The phonon dispersion calculations also show thatC2/cphase is dynamic unstable. Furthermore, we confirm that Bi2Se3possessesI4/mmmphase rather thanIm-3mand 9/10-foldC2/mphase at high pressure. Combining the experimental and theoretical results, we determine the structural phase transition sequence for Bi2Se3ofR-3m→C2/m→C2/c→I4/mmmphase under quasi-hydrostatic pressure condition andR-3m→C2/m→I4/mmmphase under nonhydrostatic pressure condition. The dynamic unstability and pressure condition sensitivity ofC2/cphase may be account for the absence ofC2/cphase in the phase transition sequence under nonhydrostatic pressure condition. Our findings obtain the high-pressure phase transition sequences of Bi2Se3under hydrostatic and nonhydrostatic pressure condition, which can facilitate researchers to explore the novel properties in layered 3D topological insulators.
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Affiliation(s)
- Xingyu Hao
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Hailiang Zhu
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of People's Republic of China
| | - Zhiying Guo
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of People's Republic of China
| | - Haijing Li
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Yu Gong
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of People's Republic of China
| | - Dongliang Chen
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of People's Republic of China
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25
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Knorr M, Schmidt P. Reactivity of Ionic Liquids: Reductive Effect of [C 4 C 1 im]BF 4 to Form Particles of Red Amorphous Selenium and Bi 2 Se 3 from Oxide Precursors. ChemistryOpen 2021; 10:125-140. [PMID: 33410604 PMCID: PMC7874247 DOI: 10.1002/open.202000264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/06/2020] [Indexed: 11/28/2022] Open
Abstract
Temperature-induced change in reactivity of the frequently used ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([C4 C1 im]BF4 ) is presented as a prerequisite for the rational screening of reaction courses in material synthesis. [C4 C1 im]BF4 becomes active with oxidic precursor compounds in reduction reaction at ϑ≥200 °C, even without the addition of an external reducing agent. The reaction mechanism of forming red amorphous selenium from SeO2 is investigated as a model system and can be described similarly to the Riley oxidation. The reactive species but-1-ene, which is formed during the decomposition of [C4 C1 im]BF4 , reacts with SeO2 and form but-3-en-2-one, water, and selenium. Elucidation of the mechanism was achieved by thermoanalytical investigations. The monotropic phase transition of selenium was analyzed by the differential scanning calorimetry. Beyond, the suitability of the single source oxide precursor Bi2 Se3 O9 for the synthesis of Bi2 Se3 particles was confirmed. Identification, characterization of formed solids succeeded by using light microscopy, XRD, SEM, and EDX.
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Affiliation(s)
- Monika Knorr
- Chair of Inorganic ChemistryBrandenburg University of Technology (BTU) Cottbus-Senftenberg Universitätsplatz 101968SenftenbergGermany
| | - Peer Schmidt
- Chair of Inorganic ChemistryBrandenburg University of Technology (BTU) Cottbus-Senftenberg Universitätsplatz 101968SenftenbergGermany
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26
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Desvignes L, Stolyarov VS, Aprili M, Massee F. Tunable High Speed Atomic Rotor in Bi 2Se 3 Revealed by Current Noise. ACS Nano 2021; 15:1421-1425. [PMID: 33444496 DOI: 10.1021/acsnano.0c08718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The ability to manipulate individual atoms and molecules using a scanning tunneling microscope (STM) has been crucial for the development of a vast array of atomic-scale devices and structures ranging from nanoscale motors and switches to quantum corrals. Molecular motors in particular have attracted considerable attention in view of their potential for assembly into complex nanoscale machines. Whereas the manipulated atoms or molecules are usually on top of a substrate, motors embedded in a lattice can be very beneficial for bottom-up construction, and may additionally be used to probe the influence of the lattice on the electronic properties of the host material. Here, we present the discovery of controlled manipulation of a rotor in Fe doped Bi2Se3. We find that the current into the rotor, which can be finely tuned with the voltage, drives omni-directional switching between three equivalent orientations, each of which can be frozen in at small bias voltage. Using current fluctuation measurements at 1 MHz and model simulations, we estimate that switching rates of hundreds of kHz for sub-nanoampere currents are achieved.
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Affiliation(s)
- Léonard Desvignes
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
| | | | - Marco Aprili
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
| | - Freek Massee
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
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27
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Wang S, Li Y, Ng A, Hu Q, Zhou Q, Li X, Liu H. 2D Bi 2Se 3 van der Waals Epitaxy on Mica for Optoelectronics Applications. Nanomaterials (Basel) 2020; 10:E1653. [PMID: 32842700 DOI: 10.3390/nano10091653] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/06/2020] [Accepted: 08/14/2020] [Indexed: 11/27/2022]
Abstract
Bi2Se3 possesses a two-dimensional layered rhombohedral crystal structure, where the quintuple layers (QLs) are covalently bonded within the layers but weakly held together by van der Waals forces between the adjacent QLs. It is also pointed out that Bi2Se3 is a topological insulator, making it a promising candidate for a wide range of electronic and optoelectronic applications. In this study, we investigate the growth of high-quality Bi2Se3 thin films on mica by the molecular beam epitaxy technique. The films exhibited a layered structure and highly c-axis-preferred growth orientation with an XRD rocking curve full-width at half-maximum (FWHM) of 0.088°, clearly demonstrating excellent crystallinity for the Bi2Se3 deposited on the mica substrate. The growth mechanism was studied by using an interface model associated with the coincidence site lattice unit (CSLU) developed for van der Waals epitaxies. This high (001) texture favors electron transport in the material. Hall measurements revealed a mobility of 726 cm2/(Vs) at room temperature and up to 1469 cm2/(Vs) at 12 K. The results illustrate excellent electron mobility arising from the superior crystallinity of the films with significant implications for applications in conducting electrodes in optoelectronic devices on flexible substrates.
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28
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Hong SB, Kim DK, Chae J, Kim K, Jeong K, Kim J, Park H, Yi Y, Cho MH. Enhanced Photoinduced Carrier Generation Efficiency through Surface Band Bending in Topological Insulator Bi 2Se 3 Thin Films by the Oxidized Layer. ACS Appl Mater Interfaces 2020; 12:26649-26658. [PMID: 32397708 DOI: 10.1021/acsami.0c05165] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Topological insulators (TIs) have become popular in the field of optoelectronic devices because of their broadband and high-sensitivity properties, which are attributed to the narrow band gap of the bulk state and high mobility of the Dirac surface state. Although perfectly grown TIs are known to exhibit strong stability against oxidation, in most cases, the existence of vacancy defects in TIs reacts to air and the characteristics of TIs is affected by oxidation. Therefore, changes in the band structure and electrical characteristics by oxidation should be considered. A significant change occurs because of the oxidation; however, the dependence of the photoresponse of TIs on oxidation has not been studied in detail. In this study, the photoresponsivity of oxidized Bi2Se3 films is enhanced, rather than degraded, after oxidation in air for 24 h, resulting in a maximum responsivity of 140 mA W-1. This responsivity is substantially higher than previously reported values for Bi2Se3. Furthermore, a change in the photoresponse time of Bi2Se3 due to air exposure is systematically observed. Based on variations in the Fermi level and work function, using photoelectron spectroscopy, it is confirmed that the responsivity is improved from the junction effect of the Bi-based surface oxidized layer.
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Affiliation(s)
- Seok-Bo Hong
- Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
- Atomic-scale Surface Science Center, Yonsei University, Seoul 03722, Republic of Korea
| | - Dae-Kyoung Kim
- Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
- Atomic-scale Surface Science Center, Yonsei University, Seoul 03722, Republic of Korea
| | - Jimin Chae
- Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
- Atomic-scale Surface Science Center, Yonsei University, Seoul 03722, Republic of Korea
| | - Kiwoong Kim
- Institute of Physics and Applied Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-go, Seoul 03722, Republic of Korea
| | - Kwangsik Jeong
- Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
- Atomic-scale Surface Science Center, Yonsei University, Seoul 03722, Republic of Korea
| | - Jonghoon Kim
- Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
- Atomic-scale Surface Science Center, Yonsei University, Seoul 03722, Republic of Korea
| | - Hanbum Park
- Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
- Atomic-scale Surface Science Center, Yonsei University, Seoul 03722, Republic of Korea
| | - Yeonjin Yi
- Institute of Physics and Applied Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-go, Seoul 03722, Republic of Korea
| | - Mann-Ho Cho
- Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
- Atomic-scale Surface Science Center, Yonsei University, Seoul 03722, Republic of Korea
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29
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Levy I, Youmans C, Garcia TA, Deng H, Alsheimer S, Testelin C, Krusin-Elbaum L, Ghaemi P, Tamargo MC. Designer Topological Insulator with Enhanced Gap and Suppressed Bulk Conduction in Bi 2Se 3/Sb 2Te 3 Ultrashort-Period Superlattices. Nano Lett 2020; 20:3420-3426. [PMID: 32315190 DOI: 10.1021/acs.nanolett.0c00338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A novel approach to suppress bulk conductance in three-dimensional (3D) topological insulators (TIs) using short-period superlattices (SLs) of two TIs is presented. Evidence for superlattice gap enhancement (SGE) was obtained from the reduction of bulk background doping from 1.2 × 1020 cm-3 to 8.5 × 1018 cm-3 as the period of Bi2Se3/Sb2Te3 SLs is decreased from 12 nm to 5 nm. Tight binding calculations show that, in the ultrashort-period regime, a significant SGE can be achieved for the resulting SL. Ultrathin short-period SLs behave as new designer TIs with bulk bandgaps up to 60% larger than the bandgap of the constituent layer of largest bandgap, while retaining topological surface features. Evidence for gap formation was obtained from ellipsometric measurements. Analysis of the weak antilocalization cusp in low-temperature magneto-conductance confirms that the top and bottom surfaces of the SL structure behave as Dirac surfaces. This approach represents a promising platform for building truly insulating TIs.
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Affiliation(s)
- Ido Levy
- Department of Chemistry, The City College of New York, New York, New York 10031, United States
- Chemistry Program, Graduate Center of CUNY, New York, New York 10021, United States
| | - Cody Youmans
- Department of Physics, The City College of New York, New York, New York 10031, United States
- Physics Program, Graduate Center of CUNY, New York, New York 10021, United States
| | - Thor Axtmann Garcia
- Department of Chemistry, The City College of New York, New York, New York 10031, United States
- Chemistry Program, Graduate Center of CUNY, New York, New York 10021, United States
| | - Haiming Deng
- Department of Physics, The City College of New York, New York, New York 10031, United States
- Physics Program, Graduate Center of CUNY, New York, New York 10021, United States
| | - Steven Alsheimer
- Department of Physics, The City College of New York, New York, New York 10031, United States
| | - Christophe Testelin
- Sorbonne Université, CNRS, Institut des NanoSciences de Paris, F-75005 Paris, France
| | - Lia Krusin-Elbaum
- Department of Physics, The City College of New York, New York, New York 10031, United States
- Physics Program, Graduate Center of CUNY, New York, New York 10021, United States
| | - Pouyan Ghaemi
- Department of Physics, The City College of New York, New York, New York 10031, United States
- Physics Program, Graduate Center of CUNY, New York, New York 10021, United States
| | - Maria C Tamargo
- Department of Chemistry, The City College of New York, New York, New York 10031, United States
- Chemistry Program, Graduate Center of CUNY, New York, New York 10021, United States
- Physics Program, Graduate Center of CUNY, New York, New York 10021, United States
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30
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Jeong K, Park H, Chae J, Sim KI, Yang WJ, Kim JH, Hong SB, Kim JH, Cho MH. Topological Phase Control of Surface States in Bi 2Se 3 via Spin-Orbit Coupling Modulation through Interface Engineering between HfO 2-X. ACS Appl Mater Interfaces 2020; 12:12215-12226. [PMID: 32073823 DOI: 10.1021/acsami.9b17555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The direct control of topological surface states in topological insulators is an important prerequisite for the application of these materials. Conventional attempts to utilize magnetic doping, mechanical tuning, structural engineering, external bias, and external magnetic fields suffer from a lack of reversible switching and have limited tunability. We demonstrate the direct control of topological phases in a bismuth selenide (Bi2Se3) topological insulator in 3 nm molecular beam epitaxy-grown films through the hybridization of the topological surface states with the hafnium (Hf) d-orbitals in the topmost layer of an underlying oxygen-deficient hafnium oxide (HfO2) substrate. The higher angular momentum of the d-orbitals of Hf is hybridized strongly by topological insulators, thereby enhancing the spin-orbit coupling and perturbing the topological surface states asymmetry in Bi2Se3. As the oxygen defect is cured or generated reversibly by external electric fields, our research facilitates the complete electrical control of the topological phases of topological insulators by controlling the defect density in the adjacent transition metal oxide. In addition, this mechanism can be applied in other related topological materials such as Weyl and Dirac semimetals in future endeavors to facilitate practical applications in unit-element devices for quantum computing and quantum communication.
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Affiliation(s)
- Kwangsik Jeong
- Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Republic of Korea
| | - Hanbum Park
- Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Republic of Korea
| | - Jimin Chae
- Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Republic of Korea
| | - Kyung-Ik Sim
- Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Republic of Korea
| | - Won Jun Yang
- Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Republic of Korea
| | - Jong-Hoon Kim
- Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Republic of Korea
| | - Seok-Bo Hong
- Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Republic of Korea
| | - Jae Hoon Kim
- Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Republic of Korea
| | - Mann-Ho Cho
- Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Republic of Korea
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31
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Pan X, He J, Gao L, Li H. Self-Filtering Monochromatic Infrared Detectors Based on Bi 2Se 3 (Sb 2Te 3)/Silicon Heterojunctions. Nanomaterials (Basel) 2019; 9:E1771. [PMID: 31842372 DOI: 10.3390/nano9121771] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 12/02/2019] [Accepted: 12/10/2019] [Indexed: 11/25/2022]
Abstract
This paper focuses on the photoelectric properties of heterostructures formed by surface-modified Si (111) and hexagonal, quintuple-layered selenides (Bi2Se3 and Sb2Te3). It was shown that H-passivated Si (111) can form robust Schottky junctions with either Bi2Se3 or Sb2Te3. When back illuminated (i.e., light incident towards the Si side of the junction), both the Bi2Se3/Si and Sb2Te3/Si junctions exhibited significant photovoltaic response at 1030 nm, which is right within the near-infrared (NIR) light wavelength range. A maximum external quantum efficiency of 14.7% with a detection response time of 2 ms for Bi2Se3/Si junction, and of 15.5% with a 0.8 ms response time for the Sb2Te3/Si junction, were achieved. Therefore, utilizing Si constituents as high-pass filters, the Bi2Se3 (Sb2Te3)/Si heterojunctions can serve as monochromatic NIR photodetectors.
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Mohammadniaei M, Nguyen HV, Tieu MV, Lee MH. 2D Materials in Development of Electrochemical Point-of-Care Cancer Screening Devices. Micromachines (Basel) 2019; 10:E662. [PMID: 31575012 PMCID: PMC6843145 DOI: 10.3390/mi10100662] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 09/28/2019] [Accepted: 09/29/2019] [Indexed: 02/07/2023]
Abstract
Effective cancer treatment requires early detection and monitoring the development progress in a simple and affordable manner. Point-of care (POC) screening can provide a portable and inexpensive tool for the end-users to conveniently operate test and screen their health conditions without the necessity of special skills. Electrochemical methods hold great potential for clinical analysis of variety of chemicals and substances as well as cancer biomarkers due to their low cost, high sensitivity, multiplex detection ability, and miniaturization aptitude. Advances in two-dimensional (2D) material-based electrochemical biosensors/sensors are accelerating the performance of conventional devices toward more practical approaches. Here, recent trends in the development of 2D material-based electrochemical biosensors/sensors, as the next generation of POC cancer screening tools, are summarized. Three cancer biomarker categories, including proteins, nucleic acids, and some small molecules, will be considered. Various 2D materials will be introduced and their biomedical applications and electrochemical properties will be given. The role of 2D materials in improving the performance of electrochemical sensing mechanisms as well as the pros and cons of current sensors as the prospective devices for POC screening will be emphasized. Finally, the future scopes of implementing 2D materials in electrochemical POC cancer diagnostics for the clinical translation will be discussed.
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Affiliation(s)
- Mohsen Mohammadniaei
- School of Integrative Engineering, Chung-Ang University, Heukseok-dong, Dongjak-gu, Seoul 06910, Korea.
| | - Huynh Vu Nguyen
- School of Integrative Engineering, Chung-Ang University, Heukseok-dong, Dongjak-gu, Seoul 06910, Korea.
| | - My Van Tieu
- School of Integrative Engineering, Chung-Ang University, Heukseok-dong, Dongjak-gu, Seoul 06910, Korea.
| | - Min-Ho Lee
- School of Integrative Engineering, Chung-Ang University, Heukseok-dong, Dongjak-gu, Seoul 06910, Korea.
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Li X, Liu Y, Fu F, Cheng M, Liu Y, Yu L, Wang W, Wan Y, Yuan Z. Single NIR Laser-Activated Multifunctional Nanoparticles for Cascaded Photothermal and Oxygen-Independent Photodynamic Therapy. Nanomicro Lett 2019; 11:68. [PMID: 34137996 PMCID: PMC7770756 DOI: 10.1007/s40820-019-0298-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 07/24/2019] [Indexed: 05/10/2023]
Abstract
Inconvenient dual-laser irradiation and tumor hypoxic environment as well as limited judgment of treating region have impeded the development of combined photothermal and photodynamic therapies (PTT and PDT). Herein, Bi2Se3@AIPH nanoparticles (NPs) are facilely developed to overcome these problems. Through a one-step method, free radical generator (AIPH) and phase transition material (lauric acid, LA, 44-46 °C) are encapsulated in hollow bismuth selenide nanoparticles (Bi2Se3 NPs). Under a single 808-nm laser irradiation at the tumor area, hyperthermia produced by Bi2Se3 not only directly leads to cell death, but also promotes AIPH release by melting LA and triggers free radical generation, which could further eradicate tumor cells in hypoxic environments. Moreover, Bi2Se3 with high X-ray attenuation coefficient endows the NPs with high computed tomography (CT) imaging capability, which is important for treating area determination. The results exhibit that Bi2Se3@AIPH NPs possesses 31.2% photothermal conversion efficiency for enhanced PTT, ideal free radical generation for oxygen-independent PDT, and 37.77 HU mL mg-1 X-ray attenuation coefficient for CT imaging with high quality. Most importantly, the tumor growth inhibition rate by synergistic PTT, PDT, and following immunotherapy is 99.6%, and even one tumor disappears completely, which demonstrates excellent cascaded synergistic effect of Bi2Se3@AIPH NPs for the tumor therapy.
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Affiliation(s)
- Xiaomin Li
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Institute of Polymer Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin, 300071, People's Republic of China
| | - Yang Liu
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Institute of Polymer Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin, 300071, People's Republic of China
| | - Fei Fu
- Department of Radiology, Tianjin Hospital, Tianjin, 300210, People's Republic of China
| | - Mingbo Cheng
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Institute of Polymer Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin, 300071, People's Republic of China
| | - Yutong Liu
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Institute of Polymer Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin, 300071, People's Republic of China
| | - Licheng Yu
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Institute of Polymer Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin, 300071, People's Republic of China
| | - Wei Wang
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Institute of Polymer Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin, 300071, People's Republic of China
| | - Yeda Wan
- Department of Radiology, Tianjin Hospital, Tianjin, 300210, People's Republic of China.
| | - Zhi Yuan
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Institute of Polymer Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin, 300071, People's Republic of China.
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Callaert C, Bercx M, Lamoen D, Hadermann J. Interstitial defects in the van der Waals gap of Bi 2Se 3. Acta Crystallogr B Struct Sci Cryst Eng Mater 2019; 75:717-732. [PMID: 32830728 DOI: 10.1107/s2052520619008357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 06/12/2019] [Indexed: 06/11/2023]
Abstract
Bi2Se3 is a thermoelectric material and a topological insulator. It is slightly conducting in its bulk due to the presence of defects and by controlling the defects different physical properties can be fine tuned. However, studies of the defects in this material are often contradicting or inconclusive. Here, the defect structure of Bi2Se3 is studied with a combination of techniques: high-resolution scanning transmission electron microscopy (HR-STEM), high-resolution energy-dispersive X-ray (HR-EDX) spectroscopy, precession electron diffraction tomography (PEDT), X-ray diffraction (XRD) and first-principles calculations using density functional theory (DFT). Based on these results, not only the observed defects are discussed, but also the discrepancies in results or possibilities across the techniques. STEM and EDX revealed interstitial defects with mainly Bi character in an octahedral coordination in the van der Waals gap, independent of the applied sample preparation method (focused ion beam milling or cryo-crushing). The inherent character of these defects is supported by their observation in the structure refinement of the EDT data. Moreover, the occupancy probability of the defects determined by EDT is inversely proportional to their corresponding DFT calculated formation energies. STEM also showed the migration of some atoms across and along the van der Waals gap. The kinetic barriers calculated using DFT suggest that some paths are possible at room temperature, while others are most probably beam induced.
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Affiliation(s)
- Carolien Callaert
- EMAT, Department of Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Marnik Bercx
- EMAT, Department of Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Dirk Lamoen
- EMAT, Department of Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Joke Hadermann
- EMAT, Department of Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
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35
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Chae J, Kang SH, Park SH, Park H, Jeong K, Kim TH, Hong SB, Kim KS, Kwon YK, Kim JW, Cho MH. Closing the Surface Bandgap in Thin Bi 2Se 3/Graphene Heterostructures. ACS Nano 2019; 13:3931-3939. [PMID: 30951288 DOI: 10.1021/acsnano.8b07012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Topological insulator (TI), a band insulator with topologically protected edge states, is one of the most interesting materials in the field of condensed matter. Bismuth selenide (Bi2Se3) is the most spotlighted three-dimensional TI material; it has a Dirac cone at each top and bottom surface and a relatively wide bandgap. For application, suppression of the bulk effect is crucial, but in ultrathin TI materials, with thicknesses less than 3 QL, the finite size effect works on the linear dispersion of the surface states, so that the surface band has a finite bandgap because of the hybridization between the top and bottom surface states and Rashba splitting, resulting from the structure inversion asymmetry. Here, we studied the gapless top surface Dirac state of strained 3 QL Bi2Se3/graphene heterostructures. A strain caused by the graphene layer reduces the bandgap of surface states, and the band bending resulting from the charge transfer at the Bi2Se3-graphene interface induces localization of surface states to each top and bottom layer to suppress the overlap of the two surface states. In addition, we verified the independent transport channel of the top surface Dirac state in Bi2Se3/graphene heterostructures by measuring the magneto-conductance. Our findings suggest that the strain and the proximity effect in TI/non-TI heterostructures may be feasible ways to engineer the topological surface states beyond the physical and topological thickness limit.
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Affiliation(s)
- Jimin Chae
- Department of Physics , Yonsei University , Seoul 03722 , Korea
| | - Seoung-Hun Kang
- Korea Institute for Advanced Study , Hoegiro 85 , Seoul 02455 , Korea
| | - Sang Han Park
- Department of Physics , Yonsei University , Seoul 03722 , Korea
- Pohang Accelerator Laboratory , POSTECH , Pohang 790-784 , Korea
| | - Hanbum Park
- Department of Physics , Yonsei University , Seoul 03722 , Korea
| | - Kwangsik Jeong
- Department of Physics , Yonsei University , Seoul 03722 , Korea
| | - Tae Hyeon Kim
- Department of Physics , Yonsei University , Seoul 03722 , Korea
| | - Seok-Bo Hong
- Department of Physics , Yonsei University , Seoul 03722 , Korea
| | - Keun Su Kim
- Department of Physics , Yonsei University , Seoul 03722 , Korea
| | - Young-Kyun Kwon
- Korea Institute for Advanced Study , Hoegiro 85 , Seoul 02455 , Korea
- Department of Physics and Research Institute for Basic Sciences , Kyung-Hee University , Seoul 02447 , Korea
| | - Jeong Won Kim
- Division of Industrial Metrology , Korea Research Institute of Standards and Science , Daejeon 34113 , Korea
| | - Mann-Ho Cho
- Department of Physics , Yonsei University , Seoul 03722 , Korea
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36
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Fedotov N, Zaitsev-Zotov S. Corrigendum: Numerical analysis of surface and edge states in slabs, stripes, rods and surface steps of topological insulators (N I Fedotov and S V Zaitsev-Zotov 2018 J. Phys.: Condens. Matter 30 485301). J Phys Condens Matter 2018; 31:049501. [PMID: 30523990 DOI: 10.1088/1361-648x/aaf53d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Corrigendum.
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Affiliation(s)
- Nikolai Fedotov
- Institut radiotehniki i elektroniki imeni V A Kotel'nikova RAN, Moskva, 125009, RUSSIAN FEDERATION
| | - Sergei Zaitsev-Zotov
- Institut radiotehniki i elektroniki imeni V A Kotel'nikova RAN, Moskva, RUSSIAN FEDERATION
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37
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Wang W, Wang X, Wang N, Ning X, Li H, Lu D, Liu X, Zhang Q, Huang Y. Bi 2Se 3 Sensitized TiO 2 Nanotube Films for Photogenerated Cathodic Protection of 304 Stainless Steel Under Visible Light. Nanoscale Res Lett 2018; 13:295. [PMID: 30242603 PMCID: PMC6150863 DOI: 10.1186/s11671-018-2717-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 09/13/2018] [Indexed: 06/08/2023]
Abstract
Titanium dioxide (TiO2) nanotube arrays coupled with a narrow gap semiconductor-bismuth selenide (Bi2Se3)-exhibited remarkable enhancement in the photocathodic protection property for 304 stainless steel under visible light. Bi2Se3/TiO2 nanocomposites were successfully synthesized using a simple two-step method, including an electrochemical anodization method for preparing pure TiO2 and a chemical bath deposition method for synthesizing Bi2Se3 nanoflowers. The morphology and structure of the composite films were studied by scanning electron microscopy, energy dispersion spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction. In addition, the influence of the Bi2Se3 content on the photoelectrochemical and photocathodic protection properties of the composite films was also studied. The photocurrent density of the Bi2Se3/TiO2 nanocomposites was significantly higher than that of pure TiO2 under visible light. The sensitizer Bi2Se3 enhanced the efficient separation of the photogenerated electron-hole pairs and the photocathodic protection properties of TiO2. Under visible light illumination, Bi2Se3/TiO2 nanocomposites synthesized by the chemical bath deposition method with Bi3+ (0.5 mmol/L) exhibited the optimal photogenerated cathodic protection performance for 304 stainless steel.
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Affiliation(s)
- Wencheng Wang
- Key Laboratory of Marine Environmental Corrosion and Bio-fouling, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071 China
- Open Studio for Marine Corrosion and Protection, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266237 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Xiutong Wang
- Key Laboratory of Marine Environmental Corrosion and Bio-fouling, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071 China
- Open Studio for Marine Corrosion and Protection, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266237 China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071 China
| | - Ning Wang
- Key Laboratory of Marine Environmental Corrosion and Bio-fouling, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Xiaobo Ning
- Open Studio for Marine Corrosion and Protection, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266237 China
| | - Hong Li
- College of Mechanical and Electrical Engineering, Qingdao University, Qingdao, 266071 China
| | - Dongzhu Lu
- Key Laboratory of Marine Environmental Corrosion and Bio-fouling, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071 China
| | - Xiangju Liu
- Key Laboratory of Marine Environmental Corrosion and Bio-fouling, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Qichao Zhang
- Key Laboratory of Marine Environmental Corrosion and Bio-fouling, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Yanliang Huang
- Key Laboratory of Marine Environmental Corrosion and Bio-fouling, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071 China
- Open Studio for Marine Corrosion and Protection, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266237 China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071 China
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38
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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 Lett 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] [What about the content of this article? (0)] [Affiliation(s)] [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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39
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Friedensen SE, Parkin WM, Mlack JT, Drndić M. Transmission Electron Microscope Nanosculpting of Topological Insulator Bismuth Selenide. ACS Nano 2018; 12:6949-6955. [PMID: 29890079 DOI: 10.1021/acsnano.8b02377] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We present a process for sculpting Bi2Se3 nanoflakes into application-relevant geometries using a high-resolution transmission electron microscope. This process takes several minutes to sculpt small areas and can be used to cut the Bi2Se3 into wires and rings, to thin areas of the Bi2Se3, and to drill circular holes and lines. We determined that this method allows for sub 10 nm features and results in clean edges along the drilled regions. Using in situ high-resolution imaging, selected area diffraction, and atomic force microscopy, we found that this lithography process preserves the crystal structure of Bi2Se3. TEM sculpting is more precise and potentially results in cleaner edges than does ion-beam modification; therefore, the promise of this method for thermoelectric and topological devices calls for further study into the transport properties of such structures.
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Affiliation(s)
- Sarah E Friedensen
- Department of Physics and Astronomy , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - William M Parkin
- Department of Physics and Astronomy , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Jerome T Mlack
- Department of Physics and Astronomy , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Marija Drndić
- Department of Physics and Astronomy , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
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40
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Moon J, Koirala N, Salehi M, Zhang W, Wu W, Oh S. Solution to the Hole-Doping Problem and Tunable Quantum Hall Effect in Bi 2Se 3 Thin Films. Nano Lett 2018; 18:820-826. [PMID: 29313354 DOI: 10.1021/acs.nanolett.7b04033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Bi2Se3, one of the most widely studied topological insulators (TIs), is naturally electron-doped due to n-type native defects. However, many years of efforts to achieve p-type Bi2Se3 thin films have failed so far. Here, we provide a solution to this long-standing problem, showing that the main culprit has been the high density of interfacial defects. By suppressing these defects through an interfacial engineering scheme, we have successfully implemented p-type Bi2Se3 thin films down to the thinnest topological regime. On this platform, we present the first tunable quantum Hall effect (QHE) study in Bi2Se3 thin films and reveal not only significantly asymmetric QHE signatures across the Dirac point but also the presence of competing anomalous states near the zeroth Landau level. The availability of doping tunable Bi2Se3 thin films will now make it possible to implement various topological quantum devices, previously inaccessible.
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Affiliation(s)
- Jisoo Moon
- Department of Physics and Astronomy and ‡Department of Materials Science and Engineering, Rutgers, The State University of New Jersey , Piscataway, New Jersey 08854, United States
| | - Nikesh Koirala
- Department of Physics and Astronomy and ‡Department of Materials Science and Engineering, Rutgers, The State University of New Jersey , Piscataway, New Jersey 08854, United States
| | - Maryam Salehi
- Department of Physics and Astronomy and ‡Department of Materials Science and Engineering, Rutgers, The State University of New Jersey , Piscataway, New Jersey 08854, United States
| | - Wenhan Zhang
- Department of Physics and Astronomy and ‡Department of Materials Science and Engineering, Rutgers, The State University of New Jersey , Piscataway, New Jersey 08854, United States
| | - Weida Wu
- Department of Physics and Astronomy and ‡Department of Materials Science and Engineering, Rutgers, The State University of New Jersey , Piscataway, New Jersey 08854, United States
| | - Seongshik Oh
- Department of Physics and Astronomy and ‡Department of Materials Science and Engineering, Rutgers, The State University of New Jersey , Piscataway, New Jersey 08854, United States
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41
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Xie L, Yang Z, Sun J, Zhou H, Chi X, Chen H, Li AX, Yao Y, Chen S. Bi 2Se 3/C Nanocomposite as a New Sodium-Ion Battery Anode Material. Nanomicro Lett 2018; 10:50. [PMID: 30393699 PMCID: PMC6199094 DOI: 10.1007/s40820-018-0201-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 04/04/2018] [Indexed: 05/19/2023]
Abstract
Bi2Se3 was studied as a novel sodium-ion battery anode material because of its high theoretical capacity and high intrinsic conductivity. Integrated with carbon, Bi2Se3/C composite shows excellent cyclic performance and rate capability. For instance, the Bi2Se3/C anode delivers an initial capacity of 527 mAh g-1 at 0.1 A g-1 and maintains 89% of this capacity over 100 cycles. The phase change and sodium storage mechanism are also carefully investigated.
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Affiliation(s)
- Lixin Xie
- Department of Physics and TcSUH, University of Houston, Houston, TX, 77204, USA
| | - Ze Yang
- Department of Physics and TcSUH, University of Houston, Houston, TX, 77204, USA
| | - Jingying Sun
- Department of Physics and TcSUH, University of Houston, Houston, TX, 77204, USA
| | - Haiqing Zhou
- Department of Physics and TcSUH, University of Houston, Houston, TX, 77204, USA
| | - Xiaowei Chi
- Department of Electrical and Computer Engineering and Materials Science and Engineering Program, University of Houston, Houston, TX, 77204, USA
| | - Hailong Chen
- The Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Andy X Li
- Clements High School, 4200 Elkins Dr, Sugar Land, TX, 77479, USA
| | - Yan Yao
- Department of Electrical and Computer Engineering and Materials Science and Engineering Program, University of Houston, Houston, TX, 77204, USA
| | - Shuo Chen
- Department of Physics and TcSUH, University of Houston, Houston, TX, 77204, USA.
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42
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Yu J, Zeng X, Zhang L, He K, Cheng S, Lai Y, Huang W, Chen Y, Yin C, Xue Q. Photoinduced Inverse Spin Hall Effect of Surface States in the Topological Insulator Bi 2Se 3. Nano Lett 2017; 17:7878-7885. [PMID: 29141404 DOI: 10.1021/acs.nanolett.7b04172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The three-dimensional (3D) topological insulator (TI) Bi2Se3 exhibits topologically protected, linearly dispersing Dirac surface states (SSs). To access the intriguing properties of these SSs, it is important to distinguish them from the coexisting two-dimensional electron gas (2DEG) on the surface. Here, we use circularly polarized light to induce the inverse spin Hall effect in a Bi2Se3 thin film at different temperatures (i.e., from 77 to 300 K). It is demonstrated that the photoinduced inverse spin Hall effect (PISHE) of the top SSs and the 2DEG can be separated based on their opposite signs. The temperature and power dependence of the PISHE also confirms our method. Furthermore, it is found that the PISHE in the 2DEG is dominated by the extrinsic mechanism, as revealed by the temperature dependence of the PISHE.
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Affiliation(s)
- Jinling Yu
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University , Fuzhou 350108, Fujian, China
| | - Xiaolin Zeng
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University , Fuzhou 350108, Fujian, China
| | - Liguo Zhang
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University , Beijing 100084, China
| | - Ke He
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University , Beijing 100084, China
| | - Shuying Cheng
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University , Fuzhou 350108, Fujian, China
- Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University , Changzhou 213164, Jiangsu China
| | - Yunfeng Lai
- Institute of Micro/Nano Devices and Solar Cells, School of Physics and Information Engineering, Fuzhou University , Fuzhou 350108, Fujian, China
- Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University , Changzhou 213164, Jiangsu China
| | - Wei Huang
- Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences , Beijing 100083, China
| | - Yonghai Chen
- Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences , Beijing 100083, China
- College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences , Beijing 100049, China
| | - Chunming Yin
- School of Physics, University of New South Wales , Sydney, New South Wales 2052, Australia
- CAS Key Laboratory of Microscale Magnetic Resonance, Department of Modern Physics, Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China , Hefei 230026, China
| | - Qikun Xue
- Department of Physics, State Key Laboratory of Low Dimensional Quantum Physics, Tsinghua University , Beijing 100084, China
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43
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Guo Y, Zhou J, Liu Y, Zhou X, Yao F, Tan C, Wu J, Lin L, Liu K, Liu Z, Peng H. Chemical Intercalation of Topological Insulator Grid Nanostructures for High-Performance Transparent Electrodes. Adv Mater 2017; 29:1703424. [PMID: 29024087 DOI: 10.1002/adma.201703424] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 08/03/2017] [Indexed: 06/07/2023]
Abstract
2D layered nanomaterials with strong covalent bonding within layers and weak van der Waals' interactions between layers have attracted tremendous interest in recent years. Layered Bi2 Se3 is a representative topological insulator material in this family, which holds promise for exploration of the fundamental physics and practical applications such as transparent electrode. Here, a simultaneous enhancement of optical transmittancy and electrical conductivity in Bi2 Se3 grid electrodes by copper-atom intercalation is presented. These Cu-intercalated 2D Bi2 Se3 electrodes exhibit high uniformity over large area and excellent stabilities to environmental perturbations, such as UV light, thermal fluctuation, and mechanical distortion. Remarkably, by intercalating a high density of copper atoms, the electrical and optical performance of Bi2 Se3 grid electrodes is greatly improved from 900 Ω sq-1 , 68% to 300 Ω sq-1 , 82% in the visible range; with better performance of 300 Ω sq-1 , 91% achieved in the near-infrared region. These unique properties of Cu-intercalated topological insulator grid nanostructures may boost their potential applications in high-performance optoelectronics, especially for infrared optoelectronic devices.
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Affiliation(s)
- Yunfan Guo
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China
| | - Jinyuan Zhou
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, P. R. China
| | - Yujing Liu
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China
| | - Xu Zhou
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, P. R. China
| | - Fengrui Yao
- State Key Laboratory for Mesoscopic Physics, School of Physics, Center for Nanochemistry, Peking University, Beijing, 100871, P. R. China
| | - Congwei Tan
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China
| | - Jinxiong Wu
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China
| | - Li Lin
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China
| | - Kaihui Liu
- State Key Laboratory for Mesoscopic Physics, School of Physics, Center for Nanochemistry, Peking University, Beijing, 100871, P. R. China
| | - Zhongfan Liu
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China
| | - Hailin Peng
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China
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44
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Dankert A, Geurs J, Kamalakar MV, Charpentier S, Dash SP. Room Temperature Electrical Detection of Spin Polarized Currents in Topological Insulators. Nano Lett 2015; 15:7976-7981. [PMID: 26560203 DOI: 10.1021/acs.nanolett.5b03080] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Topological insulators (TIs) are a new class of quantum materials that exhibit a current-induced spin polarization due to spin-momentum locking of massless Dirac Fermions in their surface states. This helical spin polarization in three-dimensional (3D) TIs has been observed using photoemission spectroscopy up to room temperatures. Recently, spin polarized surface currents in 3D TIs were detected electrically by potentiometric measurements using ferromagnetic detector contacts. However, these electric measurements are so far limited to cryogenic temperatures. Here we report the room temperature electrical detection of the spin polarization on the surface of Bi2Se3 by employing spin sensitive ferromagnetic tunnel contacts. The current-induced spin polarization on the Bi2Se3 surface is probed by measuring the magnetoresistance while switching the magnetization direction of the ferromagnetic detector. A spin resistance of up to 70 mΩ is measured at room temperature, which increases linearly with current bias, reverses sign with current direction, and decreases with higher TI thickness. The magnitude of the spin signal, its sign, and control experiments, using different measurement geometries and interface conditions, rule out other known physical effects. These findings provide further information about the electrical detection of current-induced spin polarizations in 3D TIs at ambient temperatures and could lead to innovative spin-based technologies.
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Affiliation(s)
- André Dankert
- Department of Microtechnology and Nanoscience, Chalmers University of Technology , SE 41296 Göteborg, Sweden
| | - Johannes Geurs
- Department of Microtechnology and Nanoscience, Chalmers University of Technology , SE 41296 Göteborg, Sweden
| | - M Venkata Kamalakar
- Department of Microtechnology and Nanoscience, Chalmers University of Technology , SE 41296 Göteborg, Sweden
| | - Sophie Charpentier
- Department of Microtechnology and Nanoscience, Chalmers University of Technology , SE 41296 Göteborg, Sweden
| | - Saroj P Dash
- Department of Microtechnology and Nanoscience, Chalmers University of Technology , SE 41296 Göteborg, Sweden
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45
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Hamh SY, Park SH, Han J, Jeon JH, Kahng SJ, Kim S, Choi SH, Bansal N, Oh S, Park J, Kim JS, Kim JM, Noh DY, Lee JS. Anisotropic Terahertz Emission from Bi2Se3 Thin Films with Inclined Crystal Planes. Nanoscale Res Lett 2015; 10:489. [PMID: 26694079 PMCID: PMC4688296 DOI: 10.1186/s11671-015-1190-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 02/20/2015] [Indexed: 05/06/2023]
Abstract
We investigate the surface states of topological insulator (TI) Bi2Se3 thin films grown on Si nanocrystals and Al2O3 substrates by using terahertz (THz) emission spectroscopy. Compared to bulk crystalline Bi2Te2Se, film TIs exhibit distinct behaviors in the phase and amplitude of emitted THz radiation. In particular, Bi2Se3 grown on Al2O3 shows an anisotropic response with a strong modulation of the THz signal in its phase. From x-ray diffraction, we find that the crystal plane of the Bi2Se3 films is inclined with respect to the plane of the Al2O3 substrate by about 0.27°. This structural anisotropy affects the dynamics of photocarriers and hence leads to the observed anisotropic response in the THz emission. Such relevance demonstrates that THz emission spectroscopy can be a sensitive tool to investigate the fine details of the surface crystallography and electrostatics of thin film TIs.
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Affiliation(s)
- Sun Young Hamh
- Department of Physics and Photon Science, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 500-712, South Korea.
| | - Soon-Hee Park
- Department of Physics and Photon Science, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 500-712, South Korea.
| | - Jeongwoo Han
- Department of Physics and Photon Science, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 500-712, South Korea.
| | - Jeong Heum Jeon
- Department of Physics, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 136-701, South Korea.
| | - Se-Jong Kahng
- Department of Physics, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 136-701, South Korea.
| | - Sung Kim
- Department of Applied Physics, College of Applied Science, Kyung Hee University, Yongin, 446-701, South Korea.
| | - Suk-Ho Choi
- Department of Applied Physics, College of Applied Science, Kyung Hee University, Yongin, 446-701, South Korea.
| | - Namrata Bansal
- Department of Electrical and Computer Engineering, Rutgers, The State University of New Jersey, 94 Brett Road, Piscataway, NJ, 08854, USA.
| | - Seongshik Oh
- Department of Physics and Astronomy, Rutgers, The State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ, 08854, USA.
| | - Joonbum Park
- Department of Physics, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 790-784, South Korea.
| | - Jun Sung Kim
- Department of Physics, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 790-784, South Korea.
| | - Jae Myung Kim
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
| | - Do Young Noh
- Department of Physics and Photon Science, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 500-712, South Korea.
| | - Jong Seok Lee
- Department of Physics and Photon Science, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 500-712, South Korea.
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Min Y, Park G, Kim B, Giri A, Zeng J, Roh JW, Kim SI, Lee KH, Jeong U. Synthesis of Multishell Nanoplates by Consecutive Epitaxial Growth of Bi2Se3 and Bi2Te3 Nanoplates and Enhanced Thermoelectric Properties. ACS Nano 2015; 9:6843-53. [PMID: 26134746 DOI: 10.1021/nn507250r] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
We herein demonstrate the successive epitaxial growth of Bi2Te3 and Bi2Se3 on seed nanoplates for the scalable synthesis of heterostructured nanoplates (Bi2Se3@Bi2Te3) and multishell nanoplates (Bi2Se3@Bi2Te3@Bi2Se3, Bi2Se3@Bi2Te3@Bi2Se3@Bi2Te3). The relative dimensions of the constituting layers are controllable via the molar ratios of the precursors added to the seed nanoplate solution. Reduction of the precursors produces nanoparticles that attach preferentially to the sides of the seed nanoplates. Once attached, the nanoparticles reorganize epitaxially on the seed crystal lattices to form single-crystalline core-shell nanoplates. The nanoplates, initially 100 nm wide, grew laterally to 620 nm in the multishell structure, while their thickness increased more moderately, from 5 to 20 nm. The nanoplates were pelletized into bulk samples by spark plasma sintering and their thermoelectric properties are compared. A peak thermoelectric figure of merit (ZT) ∼0.71 was obtained at 450 K for the bulk of Bi2Se3@Bi2Te3 nanoplates by simultaneous modulation of electronic and thermal transport in the presence of highly dense grain and phase boundaries.
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Affiliation(s)
- Yuho Min
- †Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seoul 120-749, Korea
| | - Gyeongbae Park
- ‡Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang 790-784, Korea
| | - Bongsoo Kim
- †Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seoul 120-749, Korea
| | - Anupam Giri
- ‡Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang 790-784, Korea
| | | | - Jong Wook Roh
- ∥Materials Research Center, Samsung Advanced Institute of Technology, Samsung Electronics, Suwon 443-803, Korea
| | - Sang Il Kim
- ∥Materials Research Center, Samsung Advanced Institute of Technology, Samsung Electronics, Suwon 443-803, Korea
| | - Kyu Hyoung Lee
- ⊥Department of Nano Applied Engineering, Kangwon National University, Chuncheon 200-701, Korea
| | - Unyong Jeong
- ‡Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang 790-784, Korea
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47
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Jung Y, Shen J, Cha JJ. Surface effects on electronic transport of 2D chalcogenide thin films and nanostructures. Nano Converg 2014; 1:18. [PMID: 28191398 PMCID: PMC5270969 DOI: 10.1186/s40580-014-0018-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 03/30/2014] [Indexed: 05/16/2023]
Abstract
The renewed interest in two-dimensional materials, particularly transition metal dichalcogenides, has been explosive, evident in a number of review and perspective articles on the topic. Our ability to synthesize and study these 2D materials down to a single layer and to stack them to form van der Waals heterostructures opens up a wide range of possibilities from fundamental studies of nanoscale effects to future electronic and optoelectronic applications. Bottom-up and top-down synthesis and basic electronic properties of 2D chalcogenide materials have been covered in great detail elsewhere. Here, we bring attention to more subtle effects: how the environmental, surface, and crystal defects modify the electronic band structure and transport properties of 2D chalcogenide nanomaterials. Surface effects such as surface oxidation and substrate influence may dominate the overall transport properties, particularly in single layer chalcogenide devices. Thus, understanding such effects is critical for successful applications based on these materials. In this review, we discuss two classes of chalcogenides - Bi-based and Mo-based chalcogenides. The first are topological insulators with unique surface electronic properties and the second are promising for flexible optoelectronic applications as well as hydrogen evolution catalytic reactions.
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Affiliation(s)
- Yeonwoong Jung
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT USA
| | - Jie Shen
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT USA
| | - Judy J Cha
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT USA
- Energy Science Institute, Yale University West Campus, West Haven, CT USA
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