1
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Adegoke TE, Abdul Ahad S, Bangert U, Geaney H, Ryan KM. Solution processable Si/Ge heterostructure NWs enabling anode mass reduction for practical full-cell Li-ion batteries. NANOSCALE ADVANCES 2023; 5:6514-6523. [PMID: 38024317 PMCID: PMC10662145 DOI: 10.1039/d3na00648d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 08/27/2023] [Indexed: 12/01/2023]
Abstract
Here, we report the solution phase synthesis of axial heterostructure Si and Ge (hSG) nanowires (NWs). The NWs were grown in a high boiling point solvent from a low-cost Sn powder to achieve a powder form product which represents an attractive route from lab-scale to commercial application. Slurry processed anodes of the NWs were investigated in half-cell (versus Li-foil) and full-cell (versus NMC811) configurations of a lithium ion battery (LIB). The hSG NW anodes yielded capacities of 1040 mA h g-1 after 150 cycles which corresponds to a 2.8 times increase compared to a standard graphite (372 mA h g-1) anode. Given the impressive specific and areal capacities of the hSG anodes, a full-cell test against a high areal capacity NMC811 cathode was examined. In full-cell configuration, use of the hSG anode resulted in a massive anode mass reduction of 50.7% compared to a standard graphite anode. The structural evolution of the hSG NW anodes into an alloyed SiGe porous mesh network was also investigated using STEM, EDX and Raman spectroscopy as a function of cycle number to fully elucidate the lithiation/delithiation mechanism of the promising anode material.
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Affiliation(s)
- Temilade Esther Adegoke
- Department of Chemical Sciences and Bernal Institute, University of Limerick Limerick V94 T9PX Ireland
| | - Syed Abdul Ahad
- Department of Chemical Sciences and Bernal Institute, University of Limerick Limerick V94 T9PX Ireland
| | - Ursel Bangert
- Department of Physics and Bernal Institute, University of Limerick Limerick V94 T9PX Ireland
| | - Hugh Geaney
- Department of Chemical Sciences and Bernal Institute, University of Limerick Limerick V94 T9PX Ireland
| | - Kevin M Ryan
- Department of Chemical Sciences and Bernal Institute, University of Limerick Limerick V94 T9PX Ireland
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2
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Effects of Different Point Defects on the Electronic Properties of III–V Al0.5Ga0.5N Photocathode Nanowires. Processes (Basel) 2022. [DOI: 10.3390/pr10040625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
AlxGa1−xN nanowires are the key materials for next-generation ultraviolet (UV) detectors. However, such devices have a low quantum efficiency caused by the introduction of defects and impurities throughout the preparation process of nanowires. Herein, the effects of different interstitial defects and vacancy defects on the electronic structure of Al0.5Ga0.5N nanowires are investigated using density functional theory calculations. Our results successfully discovered that only the formation of an N interstitial defect is thermally stable. In addition, the introduction of different defects makes the different nanowires exhibit n-type or p-type characteristics. Additionally, different defects lead to a decrease in the conduction band minimum in band structures, which is the major cause for the decrease in work function and increase in electron affinity of Al0.5Ga0.5N nanowires. What is more, the calculation of the partial density of states also proved that the interstitial defects contribute to a re-hybridization of local electron orbitals and then cause more significant movement of the electron density. Our investigations provide theoretical guidance for the pursuit of higher-quantum-efficiency ultraviolet (UV) detectors.
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3
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Sutter E, French JS, Komsa HP, Sutter P. 1D Germanium Sulfide van der Waals Bicrystals by Vapor-Liquid-Solid Growth. ACS NANO 2022; 16:3735-3743. [PMID: 35147417 DOI: 10.1021/acsnano.1c07349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Defects in two-dimensional and layered materials have attracted interest for realizing properties different from those of perfect crystals. Even stronger links between defect formation, fast growth, and emerging functionality can be found in nanostructures of van der Waals crystals, but only a few prevalent morphologies and defect-controlled synthesis processes have been identified. Here, we show that in vapor-liquid-solid growth of 1D van der Waals nanostructures, the catalyst controls the selection of the predominant (fast-growing) morphologies. Growth of layered GeS over Bi catalysts leads to two coexisting nanostructure types: chiral nanowires carrying axial screw dislocations and bicrystal nanoribbons where a central twin plane facilitates rapid growth. While Au catalysts produce exclusively dislocated nanowires, their modification with an additive triggers a switch to twinned bicrystal ribbons. Nanoscale spectroscopy shows that, while supporting fast growth, the twin defects in the distinctive layered bicrystals are electronically benign and free of nonradiative recombination centers.
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Affiliation(s)
- Eli Sutter
- Department of Mechanical and Materials Engineering and Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - Jacob S French
- Department of Electrical and Computer Engineering, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - Hannu-Pekka Komsa
- Faculty of Information Technology and Electrical Engineering, University of Oulu, FI-90014 Oulu, Finland
| | - Peter Sutter
- Department of Electrical and Computer Engineering, University of Nebraska, Lincoln, Nebraska 68588, United States
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4
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Collins GA, Kilian S, Geaney H, Ryan KM. A Nanowire Nest Structure Comprising Copper Silicide and Silicon Nanowires for Lithium-Ion Battery Anodes with High Areal Loading. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2102333. [PMID: 34263558 DOI: 10.1002/smll.202102333] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 06/04/2021] [Indexed: 06/13/2023]
Abstract
High loading (>1.6 mg cm-2 ) of Si nanowires (NWs) is achieved by seeding the growth from a dense array of Cu15 Si4 NWs using tin seeds. A one-pot synthetic approach involves the direct growth of CuSi NWs on Cu foil that acts as a textured surface for Sn adhesion and Si NW nucleation. The high achievable Si NW loading is enabled by the high surface area of CuSi NWs and bolstered by secondary growth of Si NWs as branches from both Si and CuSi NW stems, forming a dense Si active layer, interconnected with an electrically conducting CuSi array (denoted Si/CuSi). When employed as Li-ion battery anodes, the Si/CuSi nest structure demonstrates impressive rate performance, reaching 4.1 mAh cm-2 at C/20, 3.1 mAh cm-2 at C/5, and 0.8 mAh cm-2 at 6C. Also, Si/CuSi shows remarkable long-term stability, delivering a stable areal capacity of 2.2 mAh cm-2 after 300 cycles. Overall, complete anode fabrication is achieved within a single reaction by employing an inexpensive Sn powder approach.
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Affiliation(s)
- Gearoid A Collins
- Department of Chemical Sciences and Bernal Institute, University of Limerick, Limerick, Ireland
| | - Seamus Kilian
- Department of Chemical Sciences and Bernal Institute, University of Limerick, Limerick, Ireland
| | - Hugh Geaney
- Department of Chemical Sciences and Bernal Institute, University of Limerick, Limerick, Ireland
| | - Kevin M Ryan
- Department of Chemical Sciences and Bernal Institute, University of Limerick, Limerick, Ireland
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5
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Wang H, Wang A, Wang Y, Yang Z, Yang J, Han N, Chen Y. Nonpolar GaAs Nanowires Catalyzed by Cu 5As 2: Insights into As Layer Epitaxy. ACS OMEGA 2020; 5:30963-30970. [PMID: 33324804 PMCID: PMC7726767 DOI: 10.1021/acsomega.0c03817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 10/15/2020] [Indexed: 05/10/2023]
Abstract
Controlled synthesis of GaAs nanowires (NWs) with specific phases and orientations is important and challenging, which determines their electronic performances. Herein, single-crystalline GaAs NWs are successfully synthesized by using complementary metal-oxide semiconductor compatible Cu2O catalysts via chemical vapor deposition at an optimized temperature of 560 °C. In contrast to typically Au catalyzed GaAs NWs, the Cu2O catalyzed ones are found to grow along nonpolar orientations of zincblende <110> and <211> and wurtzite <1̅100> and <2̅110>. The Cu2O catalysts are found to change into orthorhombic Cu5As2 after the NW growth, which is also significantly distinguished from the Au-Ga catalyst alloy in the literature. The Cu5As2 alloy plays the epitaxy role in the nonpolar GaAs NW growth due to the lattice matching with the nonpolar planes of GaAs, which is verified by the atomic stack model. These nonpolar oriented GaAs NWs have minimized stacking faults, promising for the other semiconductor synthesis as well as electronic applications.
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Affiliation(s)
- Hang Wang
- State
Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P. R. China
- School
of Metallurgical Engineering, Xi’an
University of Architecture and Technology, Xi’an 710055, P. R. China
| | - Anqi Wang
- State
Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P. R. China
- Center
for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, P. R. China
| | - Ying Wang
- Department
of Physics, School of Science, Beijing Jiaotong
University, Beijing 100044, P. R. China
| | - Zaixing Yang
- Center
of Nanoelectronics and School of Microelectronics, Shandong University, Jinan 250100, P. R. China
| | - Jun Yang
- School
of Metallurgical Engineering, Xi’an
University of Architecture and Technology, Xi’an 710055, P. R. China
- . Tel.: +86-13152420820
| | - Ning Han
- State
Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P. R. China
- Center
for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, P. R. China
- . Tel.: 86-10-62558356
| | - Yunfa Chen
- State
Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P. R. China
- Center
for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, P. R. China
- . Tel.: 86-10-82544896
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6
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Pham T, Qamar A, Dinh T, Masud MK, Rais‐Zadeh M, Senesky DG, Yamauchi Y, Nguyen N, Phan H. Nanoarchitectonics for Wide Bandgap Semiconductor Nanowires: Toward the Next Generation of Nanoelectromechanical Systems for Environmental Monitoring. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2001294. [PMID: 33173726 PMCID: PMC7640356 DOI: 10.1002/advs.202001294] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/08/2020] [Indexed: 05/05/2023]
Abstract
Semiconductor nanowires are widely considered as the building blocks that revolutionized many areas of nanosciences and nanotechnologies. The unique features in nanowires, including high electron transport, excellent mechanical robustness, large surface area, and capability to engineer their intrinsic properties, enable new classes of nanoelectromechanical systems (NEMS). Wide bandgap (WBG) semiconductors in the form of nanowires are a hot spot of research owing to the tremendous possibilities in NEMS, particularly for environmental monitoring and energy harvesting. This article presents a comprehensive overview of the recent progress on the growth, properties and applications of silicon carbide (SiC), group III-nitrides, and diamond nanowires as the materials of choice for NEMS. It begins with a snapshot on material developments and fabrication technologies, covering both bottom-up and top-down approaches. A discussion on the mechanical, electrical, optical, and thermal properties is provided detailing the fundamental physics of WBG nanowires along with their potential for NEMS. A series of sensing and electronic devices particularly for environmental monitoring is reviewed, which further extend the capability in industrial applications. The article concludes with the merits and shortcomings of environmental monitoring applications based on these classes of nanowires, providing a roadmap for future development in this fast-emerging research field.
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Affiliation(s)
- Tuan‐Anh Pham
- Queensland Micro and Nanotechnology CentreGriffith UniversityNathanQLD4111Australia
| | - Afzaal Qamar
- Electrical Engineering DepartmentUniversity of MichiganAnn ArborMI48109USA
| | - Toan Dinh
- Queensland Micro and Nanotechnology CentreGriffith UniversityNathanQLD4111Australia
- Department of Mechanical EngineeringUniversity of Southern QueenslandSpringfieldQLD4300Australia
| | - Mostafa Kamal Masud
- Australian Institute of Bioengineering and NanotechnologyThe University of QueenslandSt LuciaQLD4072Australia
| | - Mina Rais‐Zadeh
- Electrical Engineering DepartmentUniversity of MichiganAnn ArborMI48109USA
- NASA JPLCalifornia Institute of TechnologyPasadenaCA91109USA
| | - Debbie G. Senesky
- Department of Aeronautics and AstronauticsStanford UniversityStanfordCA94305USA
| | - Yusuke Yamauchi
- Australian Institute of Bioengineering and NanotechnologyThe University of QueenslandSt LuciaQLD4072Australia
| | - Nam‐Trung Nguyen
- Queensland Micro and Nanotechnology CentreGriffith UniversityNathanQLD4111Australia
| | - Hoang‐Phuong Phan
- Queensland Micro and Nanotechnology CentreGriffith UniversityNathanQLD4111Australia
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7
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Bolshakov AD, Fedorov VV, Shugurov KY, Mozharov AM, Sapunov GA, Shtrom IV, Mukhin MS, Uvarov AV, Cirlin GE, Mukhin IS. Effects of the surface preparation and buffer layer on the morphology, electronic and optical properties of the GaN nanowires on Si. NANOTECHNOLOGY 2019; 30:395602. [PMID: 31234150 DOI: 10.1088/1361-6528/ab2c0c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The role of Si (111) substrate surface preparation and buffer layer composition in the growth, electronic and optical properties of the GaN nanowires (NWs) synthesized via plasma-assisted molecular beam epitaxy is studied. A comparison study of GaN NWs growth on the bare Si (111) substrate, silicon nitride interlayer, predeposited AlN and GaO x buffer layers, monolayer thick Ga wetting layer and GaN seeding layer prepared by the droplet epitaxy is performed. It is demonstrated that the homogeneity and the morphology of the NW arrays drastically depend on the chosen buffer layer and surface preparation technique. An effect of the buffer and seeding layers on the nucleation and desorption is also discussed. The lowest NWs surface density of 14 μm-2 is obtained on AlN buffer layer and the highest density exceeding the latter value by more than an order of magnitude corresponds to the growth on the 0.3 ML thick Ga wetting layer. It is shown, that the highest NWs mean elongation rate is obtained with AlN buffer layer, while the lowest elongation rate corresponds to the bare Si (111) surface and it is twice as lower as the first case. It is found, that use of AlN buffer layer corresponds to the most homogeneous NWs array with the smallest length dispersion while the least homogeneous array corresponds to the bare Si substrate. Vertically aligned GaN NWs array on the wide bandgap GaO x semiconductor buffer layer grown by plasma-enhanced chemical vapor deposition demonstrates its potential for electronic applications. Photoluminescence (PL) study of the synthesized samples is characterized by an intense optical response related to the excitons bound to neutral donors. The highest PL intensity is obtained in the sample with AlN buffer layer.
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Affiliation(s)
- A D Bolshakov
- St. Petersburg Academic University, Khlopina 8/3, 194021, St. Petersburg, Russia
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8
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Sun Z, Huang C, Guo J, Dong JT, Klie RF, Lauhon LJ, Seidman DN. Strain-Energy Release in Bent Semiconductor Nanowires Occurring by Polygonization or Nanocrack Formation. ACS NANO 2019; 13:3730-3738. [PMID: 30807693 DOI: 10.1021/acsnano.9b01231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Strain engineering of semiconductors is used to modulate carrier mobility, tune the energy bandgap, and drive growth of self-assembled nanostructures. Understanding strain-energy relaxation mechanisms including phase transformations, dislocation nucleation and migration, and fracturing is essential to both exploit this degree of freedom and avoid degradation of carrier lifetime and mobility, particularly in prestrained electronic devices and flexible electronics that undergo large changes in strain during operation. Raman spectroscopy, high-resolution transmission electron microscopy, and electron diffraction are utilized to identify strain-energy release mechanisms of bent diamond-cubic silicon (Si) and zinc-blende GaAs nanowires, which were elastically strained to >6% at room temperature and then annealed at an elevated temperature to activate relaxation mechanisms. High-temperature annealing of bent Si-nanowires leads to the nucleation, glide, and climb of dislocations, which align themselves to form grain boundaries, thereby reducing the strain energy. Herein, Si nanowires are reported to undergo polygonization, which is the formation of polygonal-shaped grains separated by grain boundaries consisting of aligned edge dislocations. Furthermore, strain is shown to drive dopant diffusion. In contrast to the behavior of Si, GaAs nanowires release strain energy by forming nanocracks in regions of tensile strain due to the weakening of As-bonds. These insights into the relaxation behavior of highly strained crystals can inform the design of nanoelectronic devices and provide guidance on mitigating degradation.
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Affiliation(s)
- Zhiyuan Sun
- Department of Materials Science and Engineering , Northwestern University , 2220 Campus Drive , Evanston , Illinois 60208-3108 , United States
| | - Chunyi Huang
- Department of Materials Science and Engineering , Northwestern University , 2220 Campus Drive , Evanston , Illinois 60208-3108 , United States
| | - Jinglong Guo
- Department of Physics , University of Illinois at Chicago , Chicago , Illinois 60607 , United States
| | - Jason T Dong
- Department of Materials Science and Engineering , Northwestern University , 2220 Campus Drive , Evanston , Illinois 60208-3108 , United States
| | - Robert F Klie
- Department of Physics , University of Illinois at Chicago , Chicago , Illinois 60607 , United States
| | - Lincoln J Lauhon
- Department of Materials Science and Engineering , Northwestern University , 2220 Campus Drive , Evanston , Illinois 60208-3108 , United States
| | - David N Seidman
- Department of Materials Science and Engineering , Northwestern University , 2220 Campus Drive , Evanston , Illinois 60208-3108 , United States
- Center for Atom-Probe Tomography (NUCAPT) , Northwestern University , 2220 Campus Drive , Evanston , Illinois 60208-3108 , United States
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9
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Becker J, Hill MO, Sonner M, Treu J, Döblinger M, Hirler A, Riedl H, Finley JJ, Lauhon L, Koblmüller G. Correlated Chemical and Electrically Active Dopant Analysis in Catalyst-Free Si-Doped InAs Nanowires. ACS NANO 2018; 12:1603-1610. [PMID: 29385327 DOI: 10.1021/acsnano.7b08197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Direct correlations between dopant incorporation, distribution, and their electrical activity in semiconductor nanowires (NW) are difficult to access and require a combination of advanced nanometrology methods. Here, we present a comprehensive investigation of the chemical and electrically active dopant concentrations in n-type Si-doped InAs NW grown by catalyst-free molecular beam epitaxy using various complementary techniques. N-type carrier concentrations are determined by Seebeck effect measurements and four-terminal NW field-effect transistor characterization and compared with the Si dopant distribution analyzed by local electrode atom probe tomography. With increased dopant supply, a distinct saturation of the free carrier concentration is observed in the mid-1018 cm-3 range. This behavior coincides with the incorporated Si dopant concentrations in the bulk part of the NW, suggesting the absence of compensation effects. Importantly, excess Si dopants with very high concentrations (>1020 cm-3) segregate at the NW sidewall surfaces, which confirms recent first-principles calculations and results in modifications of the surface electronic properties that are sensitively probed by field-effect measurements. These findings are expected to be relevant also for doping studies of other noncatalytic III-V NW systems.
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Affiliation(s)
- Jonathan Becker
- Walter Schottky Institut, Physik Department, and Center of Nanotechnology and Nanomaterials, Technische Universität München , Garching 85748, Germany
| | - Megan O Hill
- Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States
| | - Max Sonner
- Walter Schottky Institut, Physik Department, and Center of Nanotechnology and Nanomaterials, Technische Universität München , Garching 85748, Germany
| | - Julian Treu
- Walter Schottky Institut, Physik Department, and Center of Nanotechnology and Nanomaterials, Technische Universität München , Garching 85748, Germany
| | - Markus Döblinger
- Department of Chemistry, Ludwig-Maximilians-Universität München , Munich 81377, Germany
| | - Alexander Hirler
- Walter Schottky Institut, Physik Department, and Center of Nanotechnology and Nanomaterials, Technische Universität München , Garching 85748, Germany
| | - Hubert Riedl
- Walter Schottky Institut, Physik Department, and Center of Nanotechnology and Nanomaterials, Technische Universität München , Garching 85748, Germany
| | - Jonathan J Finley
- Walter Schottky Institut, Physik Department, and Center of Nanotechnology and Nanomaterials, Technische Universität München , Garching 85748, Germany
| | - Lincoln Lauhon
- Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States
| | - Gregor Koblmüller
- Walter Schottky Institut, Physik Department, and Center of Nanotechnology and Nanomaterials, Technische Universität München , Garching 85748, Germany
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10
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Fang Y, Jiang Y, Cherukara MJ, Shi F, Koehler K, Freyermuth G, Isheim D, Narayanan B, Nicholls AW, Seidman DN, Sankaranarayanan SKRS, Tian B. Alloy-assisted deposition of three-dimensional arrays of atomic gold catalyst for crystal growth studies. Nat Commun 2017; 8:2014. [PMID: 29222439 PMCID: PMC5722855 DOI: 10.1038/s41467-017-02025-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 11/01/2017] [Indexed: 11/10/2022] Open
Abstract
Large-scale assembly of individual atoms over smooth surfaces is difficult to achieve. A configuration of an atom reservoir, in which individual atoms can be readily extracted, may successfully address this challenge. In this work, we demonstrate that a liquid gold–silicon alloy established in classical vapor–liquid–solid growth can deposit ordered and three-dimensional rings of isolated gold atoms over silicon nanowire sidewalls. We perform ab initio molecular dynamics simulation and unveil a surprising single atomic gold-catalyzed chemical etching of silicon. Experimental verification of this catalytic process in silicon nanowires yields dopant-dependent, massive and ordered 3D grooves with spacing down to ~5 nm. Finally, we use these grooves as self-labeled and ex situ markers to resolve several complex silicon growths, including the formation of nodes, kinks, scale-like interfaces, and curved backbones. Parallel patterning of atoms over a large surface would represent a major advance over current serial methods of single atom manipulation. Here, the authors explore a periodic instability from liquid alloy droplets for high-throughput atom printing.
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Affiliation(s)
- Yin Fang
- Department of Chemistry, The University of Chicago, Chicago, IL, 60637, USA.,The James Franck Institute, The University of Chicago, Chicago, IL, 60637, USA
| | - Yuanwen Jiang
- Department of Chemistry, The University of Chicago, Chicago, IL, 60637, USA.,The James Franck Institute, The University of Chicago, Chicago, IL, 60637, USA
| | - Mathew J Cherukara
- The X-Ray Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Fengyuan Shi
- The Research Resources Center, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Kelliann Koehler
- Department of Chemistry, The University of Chicago, Chicago, IL, 60637, USA.,The James Franck Institute, The University of Chicago, Chicago, IL, 60637, USA
| | - George Freyermuth
- Department of Chemistry, The University of Chicago, Chicago, IL, 60637, USA
| | - Dieter Isheim
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA.,The Northwestern University Center for Atom-Probe Tomography (NUCAPT), Northwestern University, Evanston, IL, 60208, USA
| | - Badri Narayanan
- The Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL, 60439, USA.,Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Alan W Nicholls
- The Research Resources Center, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - David N Seidman
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA.,The Northwestern University Center for Atom-Probe Tomography (NUCAPT), Northwestern University, Evanston, IL, 60208, USA
| | - Subramanian K R S Sankaranarayanan
- The Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL, 60439, USA. .,Computation Institute, The University of Chicago, Chicago, IL, 60637, USA.
| | - Bozhi Tian
- Department of Chemistry, The University of Chicago, Chicago, IL, 60637, USA. .,The James Franck Institute, The University of Chicago, Chicago, IL, 60637, USA. .,The Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, 60637, USA.
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11
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Sun Z, Hazut O, Yerushalmi R, Lauhon LJ, Seidman DN. Criteria and considerations for preparing atom-probe tomography specimens of nanomaterials utilizing an encapsulation methodology. Ultramicroscopy 2017; 184:225-233. [PMID: 28985626 DOI: 10.1016/j.ultramic.2017.09.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/19/2017] [Accepted: 09/22/2017] [Indexed: 10/18/2022]
Abstract
Atom-probe tomography (APT) is a powerful method for characterization of nanomaterials due to its atomic-ppm level detection limit and Angstrom spatial resolution. Sample preparation for nanomaterials is, however, challenging because of their small dimensions and complicated geometries. Nanowires, with their high geometrical aspect ratio and nanowire length, 10 to 100 times their typical diameters, are highly suitable specimens for APT analyses, which can be transferred to silicon microposts using a nanomanipulator for direct APT measurements. This method is, however, prone to poor alignment and a limited field-of-view (FOV). Most importantly, direct implementation of APT with high aspect ratio nanowires may yield a low success rate of ∼30%, due to the high electric fields (10-40 V nm-1) associated with APT. While this is acceptable for samples analyzed solely by APT, a low sample yield makes it challenging to perform correlative experiments on the same nanowire specimen, utilizing other sophisticated characterization instruments. Herein, we introduce a general strategy for preparing high-yield APT specimens by encapsulating the nanowires utilizing a conformal atomic-layer deposition (ALD) coating followed by site-specific lift-out using a dual-beam focused-ion beam microscope. The ALD deposited coating forms strong chemical bonds with the Si nanowires yielding a high-quality and robust interface. The evaporation electric fields of the ALD coating and the nanowires are tuned by changing laser energy to obtain a uniform evaporation rate. The strong adhesion of the ALD-coating/nanowire interface and uniform evaporation rate produce a >90% specimen yield, with small concentration of reconstruction artifacts in 3-D. Simultaneously, the field-of-view is enhanced and the surface of the nanowire becomes visible, which makes the study of surface adsorption, segregation and oxidation possible. We utilized ALD-ZnO coated silicon nanowires as an example for investigating the criteria for choosing coating materials, laser pulse energy, laser direction, sample geometry, and substrate materials. The same criteria and considerations are applicable for preparing specimens of nanoparticles and 2-D material.
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Affiliation(s)
- Zhiyuan Sun
- Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208-3108, USA
| | - Ori Hazut
- Institute of Chemistry and the Center for Nanoscience and Nanotechnology, the Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel
| | - Roie Yerushalmi
- Institute of Chemistry and the Center for Nanoscience and Nanotechnology, the Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel
| | - Lincoln J Lauhon
- Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208-3108, USA.
| | - David N Seidman
- Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208-3108, USA; Northwestern University Center for Atom-Probe Tomography (NUCAPT), 2220 Campus Drive, Evanston, IL 60208-3108, USA.
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12
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Sun Z, Seidman DN, Lauhon LJ. Nanowire Kinking Modulates Doping Profiles by Reshaping the Liquid-Solid Growth Interface. NANO LETTERS 2017; 17:4518-4525. [PMID: 28658572 DOI: 10.1021/acs.nanolett.7b02071] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Dopants modify the electronic properties of semiconductors, including their susceptibility to etching. In semiconductor nanowires doped during growth by the vapor-liquid-solid (VLS) process, it has been shown that nanofaceting of the liquid-solid growth interface influences strongly the radial distribution of dopants. Hence, the combination of facet-dependent doping and dopant selective etching provides a means to tune simultaneously the electronic properties and morphologies of nanowires. Using atom-probe tomography, we investigated the boron dopant distribution in Au catalyzed VLS grown silicon nanowires, which regularly kink between equivalent ⟨112⟩ directions. Segments alternate between radially uniform and nonuniform doping profiles, which we attribute to switching between a concave and convex faceted liquid-solid interface. Dopant selective etching was used to reveal and correlate the shape of the growth interface with the observed anisotropic doping.
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Affiliation(s)
- Zhiyuan Sun
- Department of Materials Science and Engineering, Northwestern University , 2220 Campus Drive, Evanston, Illinois 60208-3108, United States
| | - David N Seidman
- Department of Materials Science and Engineering, Northwestern University , 2220 Campus Drive, Evanston, Illinois 60208-3108, United States
- Northwestern University Center for Atom-Probe Tomography (NUCAPT) , 2220 Campus Drive, Evanston, Illinois 60208-3108, United States
| | - Lincoln J Lauhon
- Department of Materials Science and Engineering, Northwestern University , 2220 Campus Drive, Evanston, Illinois 60208-3108, United States
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13
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Tan SL, Genuist Y, den Hertog MI, Bellet-Amalric E, Mariette H, Pelekanos NT. Highly uniform zinc blende GaAs nanowires on Si(111) using a controlled chemical oxide template. NANOTECHNOLOGY 2017; 28:255602. [PMID: 28475104 DOI: 10.1088/1361-6528/aa7169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
GaAs-based nanowires (NWs) can be grown without extrinsic catalyst using the Ga-assisted vapor-liquid-solid method in an epitaxy reactor, on Si(111) substrates covered with native oxide. Despite its wide use, the conventional method fails to provide a good control over uniformity, reproducibility, and yield of vertical NWs. The nucleation of GaAs NWs is very sensitive to the properties of the native oxide such as chemical composition, roughness and porosity. Consequently, samples grown under the same conditions on Si(111) substrates from different manufacturing batches often produce dramatically different growth results. In order to remove the dependence on wafer batch, a controlled chemical oxidation process is developed to replace the native oxide on Si(111) substrate with a reproducible chemical oxide. A high yield (exceeding 90%) of vertical GaAs NWs is achieved with excellent uniformity on chemical oxide-covered substrate. As an added advantage, the crystalline quality is significantly improved over that of GaAs NWs grown on native oxide-covered substrate, and pure zinc blende crystal structure can be achieved with minimal defects. In addition, the chemical oxide can be used as a template for producing different combinations of NW densities and sizes in parallel on the same wafer using the same growth conditions.
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Affiliation(s)
- Siew Li Tan
- Université Grenoble Alpes, F-38000 Grenoble, France. CEA, INAC, 'Nanophysique et Semiconducteurs' group, 17 rue des Martyrs, F-38054 Grenoble cedex 9, France
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14
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Conesa-Boj S, Li A, Koelling S, Brauns M, Ridderbos J, Nguyen TT, Verheijen MA, Koenraad PM, Zwanenburg FA, Bakkers EPAM. Boosting Hole Mobility in Coherently Strained [110]-Oriented Ge-Si Core-Shell Nanowires. NANO LETTERS 2017; 17:2259-2264. [PMID: 28231017 PMCID: PMC5391496 DOI: 10.1021/acs.nanolett.6b04891] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 02/07/2017] [Indexed: 05/28/2023]
Abstract
The ability of core-shell nanowires to overcome existing limitations of heterostructures is one of the key ingredients for the design of next generation devices. This requires a detailed understanding of the mechanism for strain relaxation in these systems in order to eliminate strain-induced defect formation and thus to boost important electronic properties such as carrier mobility. Here we demonstrate how the hole mobility of [110]-oriented Ge-Si core-shell nanowires can be substantially enhanced thanks to the realization of large band offset and coherent strain in the system, reaching values as high as 4200 cm2/(Vs) at 4 K and 1600 cm2/(Vs) at room temperature for high hole densities of 1019 cm-3. We present a direct correlation of (i) mobility, (ii) crystal direction, (iii) diameter, and (iv) coherent strain, all of which are extracted in our work for individual nanowires. Our results imply [110]-oriented Ge-Si core-shell nanowires as a promising candidate for future electronic and quantum transport devices.
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Affiliation(s)
- S Conesa-Boj
- Kavli Institute of Nanoscience, Delft University of Technology , Lorentzweg 1, 2628 CJ Delft, The Netherlands
- Department of Applied Physics, TU Eindhoven , Den Dolech 2, 5612 AZ Eindhoven, The Netherlands
| | - A Li
- Kavli Institute of Nanoscience, Delft University of Technology , Lorentzweg 1, 2628 CJ Delft, The Netherlands
- Department of Applied Physics, TU Eindhoven , Den Dolech 2, 5612 AZ Eindhoven, The Netherlands
| | - S Koelling
- Department of Applied Physics, TU Eindhoven , Den Dolech 2, 5612 AZ Eindhoven, The Netherlands
| | - M Brauns
- NanoElectronics Group, MESA Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - J Ridderbos
- NanoElectronics Group, MESA Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - T T Nguyen
- NanoElectronics Group, MESA Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - M A Verheijen
- Kavli Institute of Nanoscience, Delft University of Technology , Lorentzweg 1, 2628 CJ Delft, The Netherlands
- Philips Innovation Services Eindhoven , High Tech Campus 11, 5656 AE Eindhoven, The Netherlands
| | - P M Koenraad
- Department of Applied Physics, TU Eindhoven , Den Dolech 2, 5612 AZ Eindhoven, The Netherlands
| | - F A Zwanenburg
- NanoElectronics Group, MESA Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - E P A M Bakkers
- Kavli Institute of Nanoscience, Delft University of Technology , Lorentzweg 1, 2628 CJ Delft, The Netherlands
- Department of Applied Physics, TU Eindhoven , Den Dolech 2, 5612 AZ Eindhoven, The Netherlands
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15
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Choi W, Seabron E, Mohseni PK, Kim JD, Gokus T, Cernescu A, Pochet P, Johnson HT, Wilson WL, Li X. Direct Electrical Probing of Periodic Modulation of Zinc-Dopant Distributions in Planar Gallium Arsenide Nanowires. ACS NANO 2017; 11:1530-1539. [PMID: 28135065 DOI: 10.1021/acsnano.6b06853] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Selective lateral epitaxial (SLE) semiconductor nanowires (NWs), with their perfect in-plane epitaxial alignment, ability to form lateral complex p-n junctions in situ, and compatibility with planar processing, are a distinctive platform for next-generation device development. However, the incorporation and distribution of impurity dopants in these planar NWs via the vapor-liquid-solid growth mechanism remain relatively unexplored. Here, we present a detailed study of SLE planar GaAs NWs containing multiple alternating axial segments doped with Si and Zn impurities by metalorganic chemical vapor deposition. The dopant profile of the lateral multi-p-n junction GaAs NWs was imaged simultaneously with nanowire topography using scanning microwave impedance microscopy and correlated with infrared scattering-type near-field optical microscopy. Our results provide unambiguous evidence that Zn dopants in the periodically twinned and topologically corrugated p-type segments are preferentially segregated at twin plane boundaries, while Si impurity atoms are uniformly distributed within the n-type segments of the NWs. These results are further supported by microwave impedance modulation microscopy. The density functional theory based modeling shows that the presence of Zn dopant atoms reduces the formation energy of these twin planes, and the effect becomes significantly stronger with a slight increase of Zn concentration. This implies that the twin formation is expected to appear when a threshold planar concentration of Zn is achieved, making the onset and twin periodicity dependent on both Zn concentration and nanowire diameter, in perfect agreement with our experimental observations.
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Affiliation(s)
| | | | | | | | - Tobias Gokus
- neaspec GmbH, Bunsenstrasse 5, Martinsried, Munich D-821152, Germany
| | - Adrian Cernescu
- neaspec GmbH, Bunsenstrasse 5, Martinsried, Munich D-821152, Germany
| | - Pascal Pochet
- Laboratoire de Simulation Atomistique (L_Sim) , SP2M, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble F-38054, France
| | - Harley T Johnson
- Laboratoire de Simulation Atomistique (L_Sim) , SP2M, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble F-38054, France
| | - William L Wilson
- Center for Nanoscale Systems, Harvard University , 11 Oxford Street, Cambridge, Massachusetts 02138, United States
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16
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Zhang C, Huang X, Liu H, Chua SJ, Ross CA. Large-area zinc oxide nanorod arrays templated by nanoimprint lithography: control of morphologies and optical properties. NANOTECHNOLOGY 2016; 27:485604. [PMID: 27811408 DOI: 10.1088/0957-4484/27/48/485604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Vertically aligned, highly ordered, large area arrays of nanostructures are important building blocks for multifunctional devices. Here, ZnO nanorod arrays are selectively synthesized on Si substrates by a solution method within patterns created by nanoimprint lithography. The growth modes of two dimensional nucleation-driven wedding cakes and screw dislocation-driven spirals are inferred to determine the top end morphologies of the nanorods. Sub-bandgap photoluminescence of the nanorods is greatly enhanced by the manipulation of the hydrogen donors via a post-growth thermal treatment. Lasing behavior is facilitated in the nanorods with faceted top ends formed from wedding cakes growth mode. This work demonstrates the control of morphologies of oxide nanostructures in a large scale and the optimization of the optical performance.
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Affiliation(s)
- Chen Zhang
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA. Singapore-MIT Alliance, National University of Singapore, 4 Engineering Drive 3, 117576 Singapore
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17
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Xia H, Liu Z, Xu Y, Zuo J, Qin Z. Highly efficient V-Mo-Fe-O catalysts for selective oxidation of toluene to benzaldehyde. CATAL COMMUN 2016. [DOI: 10.1016/j.catcom.2016.08.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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18
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Biswas S, Doherty J, Saladukha D, Ramasse Q, Majumdar D, Upmanyu M, Singha A, Ochalski T, Morris MA, Holmes JD. Non-equilibrium induction of tin in germanium: towards direct bandgap Ge(1-x)Sn(x) nanowires. Nat Commun 2016; 7:11405. [PMID: 27095012 PMCID: PMC4843103 DOI: 10.1038/ncomms11405] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 03/22/2016] [Indexed: 01/02/2023] Open
Abstract
The development of non-equilibrium group IV nanoscale alloys is critical to achieving
new functionalities, such as the formation of a direct bandgap in a conventional
indirect bandgap elemental semiconductor. Here, we describe the fabrication of
uniform diameter, direct bandgap
Ge1−xSnx alloy nanowires, with a
Sn incorporation up to 9.2 at.%, far in excess of the
equilibrium solubility of Sn in bulk Ge, through a conventional catalytic bottom-up
growth paradigm using noble metal and metal alloy catalysts. Metal alloy catalysts
permitted a greater inclusion of Sn in Ge nanowires compared with conventional Au
catalysts, when used during vapour–liquid–solid growth. The
addition of an annealing step close to the Ge-Sn eutectic temperature
(230 °C) during cool-down, further facilitated the excessive
dissolution of Sn in the nanowires. Sn was distributed throughout the Ge nanowire
lattice with no metallic Sn segregation or precipitation at the surface or within
the bulk of the nanowires. The non-equilibrium incorporation of Sn into the Ge
nanowires can be understood in terms of a kinetic trapping model for impurity
incorporation at the triple-phase boundary during growth. Direct band gap nanostructures compatible with Si-based electronics
are actively investigated. Here, Biswas et al. incorporate unusually large
amounts of tin in germanium nanowires by non-equilibrium kinetic trapping, and optical
characterizations suggest that the nanowires exhibit a direct band gap.
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Affiliation(s)
- Subhajit Biswas
- Materials Chemistry &Analysis Group, Department of Chemistry, Tyndall National Institute, University College Cork, Cork T12 YF78, Ireland
| | - Jessica Doherty
- Materials Chemistry &Analysis Group, Department of Chemistry, Tyndall National Institute, University College Cork, Cork T12 YF78, Ireland
| | - Dzianis Saladukha
- Department of Photonics, Tyndall National Institute, University College Cork, Cork T12 R5CP, Ireland.,CAPPA, Cork Institute of Technology, Cork T12 T66T, Ireland
| | - Quentin Ramasse
- SuperSTEM Laboratory, SciTech Daresbury Campus, Daresbury WA4 4AD, UK
| | | | - Moneesh Upmanyu
- Group for Simulation and Theory of Atomic-Scale Material Phenomena (stAMP), Department of Mechanical and Industrial Engineering and Department of Bioengineering, Northeastern University, Boston, Massachusetts 02115, USA
| | - Achintya Singha
- Department of Physics, Bose Institute, Kolkata 700009, India
| | - Tomasz Ochalski
- Department of Photonics, Tyndall National Institute, University College Cork, Cork T12 R5CP, Ireland.,CAPPA, Cork Institute of Technology, Cork T12 T66T, Ireland
| | | | - Justin D Holmes
- Materials Chemistry &Analysis Group, Department of Chemistry, Tyndall National Institute, University College Cork, Cork T12 YF78, Ireland.,AMBER, CRANN, Trinity College Dublin, Dublin D02 R590, Ireland
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19
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Design and fabrication of 1-D semiconductor nanomaterials for high-performance photovoltaics. Sci Bull (Beijing) 2016. [DOI: 10.1007/s11434-016-1028-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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20
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Luo Z, Jiang Y, Myers BD, Isheim D, Wu J, Zimmerman JF, Wang Z, Li Q, Wang Y, Chen X, Dravid VP, Seidman DN, Tian B. Atomic gold-enabled three-dimensional lithography for silicon mesostructures. Science 2015; 348:1451-5. [DOI: 10.1126/science.1257278] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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21
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Sundara Venkatesh P, Jeganathan K. Investigations on the morphological evolution of zinc oxide nanostructures and their optical properties. CrystEngComm 2014. [DOI: 10.1039/c4ce00849a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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22
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Incorporation and redistribution of impurities into silicon nanowires during metal-particle-assisted growth. Nat Commun 2014; 5:4134. [PMID: 24920212 DOI: 10.1038/ncomms5134] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 05/15/2014] [Indexed: 11/08/2022] Open
Abstract
The incorporation of metal atoms into silicon nanowires during metal-particle-assisted growth is a critical issue for various nanowire-based applications. Here we have been able to access directly the incorporation and redistribution of metal atoms into silicon nanowires produced by two different processes at growth rates ranging from 3 to 40 nm s(-1), by using laser-assisted atom probe tomography and scanning transmission electron microscopy. We find that the concentration of metal impurities in crystalline silicon nanowires increases with the growth rate and can reach a level of two orders of magnitude higher than that in their equilibrium solubility. Moreover, we demonstrate that the impurities are first incorporated into nanowire volume and then segregate at defects such as the twin planes. A dimer-atom-insertion kinetic model is proposed to account for the impurity incorporation into nanowires.
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23
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Gamalski AD, Voorhees PW, Ducati C, Sharma R, Hofmann S. Twin plane re-entrant mechanism for catalytic nanowire growth. NANO LETTERS 2014; 14:1288-1292. [PMID: 24527789 DOI: 10.1021/nl404244u] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A twin-plane based nanowire growth mechanism is established using Au catalyzed Ge nanowire growth as a model system. Video-rate lattice-resolved environmental transmission electron microscopy shows a convex, V-shaped liquid catalyst-nanowire growth interface for a ⟨112⟩ growth direction that is composed of two Ge {111} planes that meet at a twin boundary. Unlike bulk crystals, the nanowire geometry allows steady-state growth with a single twin boundary at the nanowire center. We suggest that the nucleation barrier at the twin-plane re-entrant groove is effectively reduced by the line energy, and hence the twin acts as a preferential nucleation site that dictates the lateral step flow cycle which constitutes nanowire growth.
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Affiliation(s)
- Andrew D Gamalski
- Department of Engineering, University of Cambridge , Cambridge CB3 0FA, United Kingdom
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24
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Grain boundaries in nanocrystalline catalytic materials as a source of surface chemical functionality. REV CHEM ENG 2014. [DOI: 10.1515/revce-2014-0011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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25
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Jeon N, Dayeh SA, Lauhon LJ. Origin of polytype formation in VLS-grown Ge nanowires through defect generation and nanowire kinking. NANO LETTERS 2013; 13:3947-3952. [PMID: 23898822 DOI: 10.1021/nl402117b] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We propose layer-by-layer growth mechanisms to account for planar defect generation leading to kinked polytype nanowires. Cs-corrected scanning transmission electron microscopy enabled identification of stacking sequences of distinct polytype bands found in kinked nanowires, and Raman spectroscopy was used to distinguish polytype nanowires from twinned nanowires containing only the 3C diamond cubic phase. The faceting and atomic-scale defect structures of twinned 3C are compared with those of polytype nanowires to develop a common model linking nucleation pinning to nanowire morphology and phase.
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Affiliation(s)
- Nari Jeon
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
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26
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Cha SI, Hwang KH, Kim YH, Yun MJ, Seo SH, Shin YJ, Moon JH, Lee DY. Crystal splitting and enhanced photocatalytic behavior of TiO2 rutile nano-belts induced by dislocations. NANOSCALE 2013; 5:753-758. [PMID: 23223582 DOI: 10.1039/c2nr33028h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Crystal splitting and enhanced photocatalytic activities caused by implied dislocations were observed in hierarchical TiO(2) nano-architectures prepared by one-pot hydrothermal synthesis in concentrated HCl. Microstructural observation revealed that the nanowires formed by continuous splitting of TiO(2) nano-belts, which is caused by a lattice misorientation of about 6°, were generated by an array of dislocations. In addition, the larger amount of dislocations implied in TiO(2) nano-architectures induces higher photocatalytic activities under ultra-violet illumination.
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Affiliation(s)
- Seung I Cha
- Nano Hybrid Technology Research Center, Creative and Fundamental Research Division, Korea Electrotechnology Research Institute, Boolmosan-ro 10beon-gil, Seongsan-gu, Changwon 641-120, Korea.
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27
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Bogart TD, Lu X, Korgel BA. Precision synthesis of silicon nanowires with crystalline core and amorphous shell. Dalton Trans 2013; 42:12675-80. [DOI: 10.1039/c3dt50875g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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28
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Wang H, Zepeda-Ruiz LA, Gilmer GH, Upmanyu M. Atomistics of vapour-liquid-solid nanowire growth. Nat Commun 2013; 4:1956. [PMID: 23752586 PMCID: PMC3709494 DOI: 10.1038/ncomms2956] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 04/29/2013] [Indexed: 11/09/2022] Open
Abstract
Vapour-liquid-solid route and its variants are routinely used for scalable synthesis of semiconducting nanowires, yet the fundamental growth processes remain unknown. Here we employ atomic-scale computations based on model potentials to study the stability and growth of gold-catalysed silicon nanowires. Equilibrium studies uncover segregation at the solid-like surface of the catalyst particle, a liquid AuSi droplet, and a silicon-rich droplet-nanowire interface enveloped by heterogeneous truncating facets. Supersaturation of the droplets leads to rapid one-dimensional growth on the truncating facets and much slower nucleation-controlled two-dimensional growth on the main facet. Surface diffusion is suppressed and the excess Si flux occurs through the droplet bulk which, together with the Si-rich interface and contact line, lowers the nucleation barrier on the main facet. The ensuing step flow is modified by Au diffusion away from the step edges. Our study highlights key interfacial characteristics for morphological and compositional control of semiconducting nanowire arrays.
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Affiliation(s)
- Hailong Wang
- Group for Simulation and Theory of Atomic-Scale Material Phenomena (stAMP), Department of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts 02115, USA
- School of Engineering, Brown University, Providence, Rhode Island 02912, USA
| | - Luis A. Zepeda-Ruiz
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - George H. Gilmer
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
- Division of Engineering, Colorado School of Mines, Golden, Colorado 80401, USA
| | - Moneesh Upmanyu
- Group for Simulation and Theory of Atomic-Scale Material Phenomena (stAMP), Department of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts 02115, USA
- Department of Bioengineering, Northeastern University, Boston, Massachusetts 02115, USA
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29
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Schreiber DK, Adusumilli P, Hemesath ER, Seidman DN, Petford-Long AK, Lauhon LJ. A method for directly correlating site-specific cross-sectional and plan-view transmission electron microscopy of individual nanostructures. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2012; 18:1410-1418. [PMID: 23146147 DOI: 10.1017/s1431927612013517] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A sample preparation method is described for enabling direct correlation of site-specific plan-view and cross-sectional transmission electron microscopy (TEM) analysis of individual nanostructures by employing a dual-beam focused-ion beam (FIB) microscope. This technique is demonstrated using Si nanowires dispersed on a TEM sample support (lacey carbon or Si-nitride). Individual nanowires are first imaged in the plan-view orientation to identify a region of interest; in this case, impurity atoms distributed at crystalline defects that require further investigation in the cross-sectional orientation. Subsequently, the region of interest is capped with a series of ex situ and in situ deposited layers to protect the nanowire and facilitate site-specific lift-out and cross-sectioning using a dual-beam FIB microscope. The lift-out specimen is thinned to electron transparency with site-specific positioning to within ≈ 200 nm of a target position along the length of the nanowire. Using the described technique, it is possible to produce correlated plan-view and cross-sectional view lattice-resolved TEM images that enable a quasi-3D analysis of crystalline defect structures in a specific nanowire. While the current study is focused on nanowires, the procedure described herein is general for any electron-transparent sample and is broadly applicable for many nanostructures, such as nanowires, nanoparticles, patterned thin films, and devices.
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Affiliation(s)
- Daniel K Schreiber
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208-3108, USA.
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30
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Hemesath ER, Schreiber DK, Kisielowski CF, Petford-Long AK, Lauhon LJ. Atomic structural analysis of nanowire defects and polytypes enabled through cross-sectional lattice imaging. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2012; 8:1717-1724. [PMID: 22447661 DOI: 10.1002/smll.201102404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Revised: 01/12/2012] [Indexed: 05/31/2023]
Abstract
Correlated transmission electron microscopy imaging, electron diffraction, and Raman spectroscopy are used to investigate the structure of Si nanowires with planar defects. In addition to plan-view imaging, individual defective nanowires are imaged in axial cross-section at specific locations selected in plan-view imaging. This correlated characterization approach enables definitive identification of complex defect structures that give rise to diffraction patterns that have been misinterpreted in the literature. Conclusive evidence for the 9R Si polytype is presented, and the atomic structure of this phase is correlated with kinematically-forbidden reflections in Si diffraction patterns. Despite striking similarities between imaging and diffraction data from twinned nanowires and the 9R polytype, clear distinctions between the structures can be made. Finally, the structural origins of ⅓{422} reflections in Si [111] diffraction patterns are identified.
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Affiliation(s)
- Eric R Hemesath
- Department of Materials Science and Engineering, Northwestern University, 2220 N Campus Dr., Evanston IL 60208, USA
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31
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Bar-Sadan M, Barthel J, Shtrikman H, Houben L. Direct imaging of single Au atoms within GaAs nanowires. NANO LETTERS 2012; 12:2352-6. [PMID: 22497234 DOI: 10.1021/nl300314k] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Incorporation of catalyst atoms during the growth process of semiconductor nanowires reduces the electron mean free path and degrades their electronic properties. Aberration-corrected scanning transmission electron microscopy (STEM) is now capable of directly imaging single Au atoms within the dense matrix of a GaAs crystal, by slightly tilting the GaAs lattice planes with respect to the incident electron beam. Au doping values in the order of 10(17-18) cm(3) were measured, making ballistic transport through the nanowires practically inaccessible.
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Affiliation(s)
- Maya Bar-Sadan
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
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Venkatesh PS, Purushothaman V, Muthu SE, Arumugam S, Ramakrishnan V, Jeganathan K, Ramamurthi K. Role of point defects on the enhancement of room temperature ferromagnetism in ZnO nanorods. CrystEngComm 2012. [DOI: 10.1039/c2ce25098e] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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