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Sikora O, Sternik M, Jany BR, Krok F, Piekarz P, Oleś AM. Density functional theory study of Au-fcc/Ge and Au-hcp/Ge interfaces. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2023; 14:1093-1105. [PMID: 38025198 PMCID: PMC10679839 DOI: 10.3762/bjnano.14.90] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 10/13/2023] [Indexed: 12/01/2023]
Abstract
In recent years, nanostructures with hexagonal polytypes of gold have been synthesised, opening new possibilities in nanoscience and nanotechnology. As bulk gold crystallizes in the fcc phase, surface effects can play an important role in stabilizing hexagonal gold nanostructures. Here, we investigate several heterostructures with Ge substrates, including the fcc and hcp phases of gold that have been observed experimentally. We determine and discuss their interfacial energies and optimized atomic arrangements, comparing the theory results with available experimental data. Our DFT calculations for the Au-fcc(011)/Ge(001) junction show how the presence of defects in the interface layer can help to stabilize the atomic pattern, consistent with microscopic images. Although the Au-hcp/Ge interface is characterized by a similar interface energy, it reveals large atomic displacements due to significant mismatch. Finally, analyzing the electronic properties, we demonstrate that Au/Ge systems have metallic character, but covalent-like bonding states between interfacial Ge and Au atoms are also present.
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Affiliation(s)
- Olga Sikora
- Faculty of Materials Engineering and Physics, Cracow University of Technology, Podchorążych 1, PL-30084 Kraków, Poland
| | - Małgorzata Sternik
- Institute of Nuclear Physics, Polish Academy of Sciences, W. E. Radzikowskiego 152, PL-31342 Kraków, Poland
| | - Benedykt R Jany
- Marian Smoluchowski Institute of Physics, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Łojasiewicza 11, 30348 Krakow, Poland
| | - Franciszek Krok
- Marian Smoluchowski Institute of Physics, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Łojasiewicza 11, 30348 Krakow, Poland
| | - Przemysław Piekarz
- Institute of Nuclear Physics, Polish Academy of Sciences, W. E. Radzikowskiego 152, PL-31342 Kraków, Poland
| | - Andrzej M Oleś
- Institute of Theoretical Physics, Jagiellonian University, Prof. Stanisława Łojasiewicza 11, PL-30348 Kraków, Poland
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2
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Zhang Q, Kusada K, Kitagawa H. Phase Control of Noble Monometallic and Alloy Nanomaterials by Chemical Reduction Methods. Chempluschem 2021; 86:504-519. [PMID: 33764700 DOI: 10.1002/cplu.202000782] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 03/15/2021] [Indexed: 12/28/2022]
Abstract
In recent years, the phase control of monometallic and alloy nanomaterials has attracted great attention because of the potential to tune the physical and chemical properties of these species. In this Review, an overview of the latest research progress in phase-controlled monometallic and alloy nanomaterials is first given. Then, the phase-controlled synthesis using a chemical reduction method are discussed, and the formation mechanisms of these nanomaterials are specifically highlighted. Lastly, the challenges and future perspectives in this new research field are discussed.
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Affiliation(s)
- Quan Zhang
- Department of Chemistry, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Kohei Kusada
- Department of Chemistry, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Hiroshi Kitagawa
- Department of Chemistry, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto, 606-8502, Japan
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3
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Cajzl J, Jeníčková K, Nekvindová P, Michalcová A, Veselý M, Macková A, Malinský P, Jágerová A, Mikšová R, Akhmadaliev S. Creation of Gold Nanoparticles in ZnO by Ion Implantation-DFT and Experimental Studies. NANOMATERIALS 2020; 10:nano10122392. [PMID: 33265978 PMCID: PMC7760233 DOI: 10.3390/nano10122392] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/26/2020] [Accepted: 11/27/2020] [Indexed: 12/22/2022]
Abstract
Three different crystallographic orientations of the wurtzite ZnO structure (labeled as c-plane, a-plane and m-plane) were implanted with Au+ ions using various energies and fluences to form gold nanoparticles (GNPs). The ion implantation process was followed by annealing at 600 °C in an oxygen atmosphere to decrease the number of unwanted defects and improve luminescence properties. With regard to our previous publications, the paper provides a summary of theoretical and experimental results, i.e., both DFT and FLUX simulations, as well as experimental results from TEM, HRTEM, RBS, RBS/C, Raman spectroscopy and photoluminescence. From the results, it follows that in the ZnO structure, implanted gold atoms are located in random interstitial positions -experimentally, the amount of interstitial gold atoms increased with increasing ion implantation fluence. During ion implantation and subsequent annealing, the metal clusters and nanoparticles with sizes from 2 to 20 nm were formed. The crystal structure of the resulting gold was not cubic (confirmed by diffraction patterns), but it had a hexagonal close-packed (hcp) arrangement. The ion implantation of gold leads to the creation of Zn and O interstitial defects and extended defects with distinct character in various crystallographic cuts of ZnO, where significant O-sublattice disordering occurred in m-plane ZnO.
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Affiliation(s)
- Jakub Cajzl
- Department of Inorganic Chemistry, University of Chemistry and Technology, 166 28 Prague, Czech Republic; (K.J.); (P.N.)
- Correspondence:
| | - Karla Jeníčková
- Department of Inorganic Chemistry, University of Chemistry and Technology, 166 28 Prague, Czech Republic; (K.J.); (P.N.)
| | - Pavla Nekvindová
- Department of Inorganic Chemistry, University of Chemistry and Technology, 166 28 Prague, Czech Republic; (K.J.); (P.N.)
| | - Alena Michalcová
- Department of Metals and Corrosion Engineering, University of Chemistry and Technology, 166 28 Prague, Czech Republic;
| | - Martin Veselý
- Department of Organic Technology, University of Chemistry and Technology, 166 28 Prague, Czech Republic;
| | - Anna Macková
- Nuclear Physics Institute of the Czech Academy of Sciences, 250 68 Řež, Czech Republic; (A.M.); (P.M.); (A.J.); (R.M.)
- Department of Physics, Faculty of Science, J.E. Purkinje University, 400 96 Ústí nad Labem, Czech Republic
| | - Petr Malinský
- Nuclear Physics Institute of the Czech Academy of Sciences, 250 68 Řež, Czech Republic; (A.M.); (P.M.); (A.J.); (R.M.)
- Department of Physics, Faculty of Science, J.E. Purkinje University, 400 96 Ústí nad Labem, Czech Republic
| | - Adéla Jágerová
- Nuclear Physics Institute of the Czech Academy of Sciences, 250 68 Řež, Czech Republic; (A.M.); (P.M.); (A.J.); (R.M.)
- Department of Physics, Faculty of Science, J.E. Purkinje University, 400 96 Ústí nad Labem, Czech Republic
| | - Romana Mikšová
- Nuclear Physics Institute of the Czech Academy of Sciences, 250 68 Řež, Czech Republic; (A.M.); (P.M.); (A.J.); (R.M.)
| | - Shavkat Akhmadaliev
- Institute of Ion Beam Physics and Materials Research, Helmholtz Zentrum Dresden-Rossendorf, 01328 Dresden, Germany;
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Lu S, Liang J, Long H, Li H, Zhou X, He Z, Chen Y, Sun H, Fan Z, Zhang H. Crystal Phase Control of Gold Nanomaterials by Wet-Chemical Synthesis. Acc Chem Res 2020; 53:2106-2118. [PMID: 32972128 DOI: 10.1021/acs.accounts.0c00487] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Gold (Au), a transition metal with an atomic number of 79 in the periodic table of elements, was discovered in approximately 3000 B.C. Due to the ultrahigh chemical stability and brilliant golden color, Au had long been thought to be a most inert material and was widely utilized in art, jewelry, and finance. However, it has been found that Au becomes exceptionally active as a catalyst when its size shrinks to the nanometer scale. With continuous efforts toward the exploration of catalytic applications over the past decades, Au nanomaterials show critical importance in many catalytic processes. Besides catalysis, Au nanomaterials also possess other promising applications in plasmonics, sensing, biology and medicine, due to their unique localized surface plasmon resonance, intriguing biocompatibility, and superior stability. Unfortunately, the practical applications of Au nanomaterials could be limited because of the scarce reserves and high price of Au. Therefore, it is quite essential to further explore novel physicochemical properties and functions of Au nanomaterials so as to enhance their performance in different types of applications.Recently, phase engineering of nanomaterials (PEN), which involves the rearrangement of atoms in the unit cell, has emerged as a fantastic and effective strategy to adjust the intrinsic physicochemical properties of nanomaterials. In this Account, we give an overview of the recent progress on crystal phase control of Au nanomaterials using wet-chemical synthesis. Starting from a brief introduction of the research background, we first describe the development history of wet-chemical synthesis of Au nanomaterials and especially emphasize the key research findings. Subsequently, we introduce the typical Au nanomaterials with untraditional crystal phases and heterophases that have been observed, such as 2H, 4H, body-centered phases, and crystal-phase heterostructures. Importantly, crystal phase control of Au nanomaterials by wet-chemical synthesis is systematically described. After that, we highlight the importance of crystal phase control in Au nanomaterials by demonstrating the remarkable effect of crystal phases on their physicochemical properties (e.g., electronic and optical properties) and potential applications (e.g., catalysis). Finally, after a concise summary of recent advances in this emerging research field, some personal perspectives are provided on the challenges, opportunities, and research directions in the future.
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Affiliation(s)
- Shiyao Lu
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Jinzhe Liang
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Huiwu Long
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
- Hong Kong Branch of National Precious Metals Material Engineering Research Center, City University of Hong Kong, Hong Kong, China
| | - Huangxu Li
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Xichen Zhou
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Zhen He
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
- Hong Kong Branch of National Precious Metals Material Engineering Research Center, City University of Hong Kong, Hong Kong, China
| | - Ye Chen
- Department of Chemistry, The Chinese University of Hong Kong, Hong Kong, China
| | - Hongyan Sun
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Zhanxi Fan
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
- Hong Kong Branch of National Precious Metals Material Engineering Research Center, City University of Hong Kong, Hong Kong, China
| | - Hua Zhang
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
- Hong Kong Branch of National Precious Metals Material Engineering Research Center, City University of Hong Kong, Hong Kong, China
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Zhang X, Zhang X, Yuan B, Liang C, Yu Y. Atomic-scale study of nanocatalysts by aberration-corrected electron microscopy. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:413004. [PMID: 32666936 DOI: 10.1088/1361-648x/ab977c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 05/28/2020] [Indexed: 06/11/2023]
Abstract
Aberration-corrected electron microscopy (AC-EM) including transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) has become one of the most powerful technologies in the studies of nanocatalysts. With the current spatial resolution of sub-0.5 Å and energy resolution of 10 meV, AC-EM can quantificationally articulate the connection between catalytic properties and atomic configurations of nanocatalysts. However, the restricted irradiation sensitive characteristics of specimens pose an obstacle to solve their intrinsic structure. Low-dose imaging should be applied to overcome this problem. In addition, the choice of appropriate imaging method is also crucial to tackle specific structural problems of nanocatalysts. On the basis of careful management of electron dose and selection of suitable imaging method,in situgas and liquid S/TEM are able to reveal the structure evolution of nanocatalysts in real-time. Further combination with residual gas analysis would deepen the understanding of the catalytic reaction.
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Affiliation(s)
- Xun Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China
| | - Xiuli Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China
| | - Biao Yuan
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China
| | - Chao Liang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China
| | - Yi Yu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China
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Cheng H, Yang N, Lu Q, Zhang Z, Zhang H. Syntheses and Properties of Metal Nanomaterials with Novel Crystal Phases. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1707189. [PMID: 29658155 DOI: 10.1002/adma.201707189] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 01/09/2018] [Indexed: 05/13/2023]
Abstract
In recent decades, researchers have devoted tremendous effort into the rational design and controlled synthesis of metal nanomaterials with well-defined size, morphology, composition, and structure, and great achievements have been reached. However, the crystal-phase engineering of metal nanomaterials still remains a big challenge. Recent research has revealed that the crystal phase of metal nanomaterials can significantly alter their properties, arising from the distinct atomic arrangement and modified electronic structure. Until now, it has been relatively uncommon to synthesize metal nanomaterials with novel crystal phases in spite of the fact that these nanostructures would be promising for various applications. Here, the research progress regarding the fine control of noble metal (Au, Ag, Ru, Rh, Pd) and non-noble metal (Fe, Co, Ni) nanomaterials with novel crystal phases is reviewed. First, synthesis strategies and their phase transformations are summarized, while highlighting the peculiar characteristics of each element. The phase-dependent properties are then discussed by providing representative examples. Finally, the challenges and perspectives in this emerging field are proposed.
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Affiliation(s)
- Hongfei Cheng
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Nailiang Yang
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Qipeng Lu
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Zhicheng Zhang
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Hua Zhang
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
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Controlled growth of hexagonal gold nanostructures during thermally induced self-assembling on Ge(001) surface. Sci Rep 2017; 7:42420. [PMID: 28195226 PMCID: PMC5307968 DOI: 10.1038/srep42420] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 01/09/2017] [Indexed: 11/14/2022] Open
Abstract
Nano-sized gold has become an important material in various fields of science and technology, where control over the size and crystallography is desired to tailor the functionality. Gold crystallizes in the face-centered cubic (fcc) phase, and its hexagonal closed packed (hcp) structure is a very unusual and rare phase. Stable Au hcp phase has been reported to form in nanoparticles at the tips of some Ge nanowires. It has also recently been synthesized in the form of thin graphene-supported sheets which are unstable under electron beam irradiation. Here, we show that stable hcp Au 3D nanostructures with well-defined crystallographic orientation and size can be systematically created in a process of thermally induced self-assembly of thin Au layer on Ge(001) monocrystal. The Au hcp crystallite is present in each Au nanostructure and has been characterized by different electron microscopy techniques. We report that a careful heat treatment above the eutectic melting temperature and a controlled cooling is required to form the hcp phase of Au on a Ge single crystal. This new method gives scientific prospects to obtain stable Au hcp phase for future applications in a rather simple manner as well as redefine the phase diagram of Gold with Germanium.
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8
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Yang J, Zhang Q, Chen L, Wang G, Chen X. Formation and Stability of Low-Dimensional Structures for Group VIIIB and IB Transition Metals: The Role of sd 4 Hybridization. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2016; 3:1500314. [PMID: 27981017 PMCID: PMC5115452 DOI: 10.1002/advs.201500314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 10/25/2015] [Indexed: 06/06/2023]
Abstract
A quasi-sd4 hybridization state for group VIIIB and IB face-centered cubic (FCC) transition metals in low-dimensional nanostructures is identified, in contrast to the sd5 hybridization state in bulk. For Au, a novel three-shelled nanowire is designed with a hexagonal close-packed core in the sd5 hybridization, wrapped by FCC-(111) shell that adopts the quasi-sd4 hybridization. This new nanostructure exhibits remarkable stability and electronic properties.
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Affiliation(s)
- Jianhui Yang
- Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo Zhejiang 315201 P.R. China
| | - Qiuju Zhang
- Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo Zhejiang 315201 P.R. China
| | - Liang Chen
- Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo Zhejiang 315201 P.R. China
| | - Gang Wang
- Research and Development Center for Functional Crystals Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 P.R. China
| | - Xiaolong Chen
- Research and Development Center for Functional Crystals Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 P.R. China; Collaborative Innovation Center of Quantum Matter Beijing 100190 P.R. China
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Kusada K, Kitagawa H. A Route for Phase Control in Metal Nanoparticles: A Potential Strategy to Create Advanced Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:1129-1142. [PMID: 26539900 DOI: 10.1002/adma.201502881] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 07/15/2015] [Indexed: 06/05/2023]
Abstract
There is untapped potential for materials whose crystal structures are unobtainable in the bulk state. Several examples of such structures have been found in nanomaterials, and these materials exhibit unique properties that arise from their unique electronic states and surface structures. Here, recent developments in the syntheses of these nanomaterials and their unique properties, such as hydrogen-storage ability and catalytic activity, are summarized. Firstly, the syntheses and properties of novel solid-solution alloy nanoparticles in immiscible alloy systems such as Ag-Rh and Pd-Ru are introduced. Following this, the crystal structure control of nanoscale Ru is discussed. These unique alloy materials show enhanced properties and highlight the potential of phase control to be a new strategy for nanomaterial development.
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Affiliation(s)
- Kohei Kusada
- Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto, 606-8502, Japan
- JST CREST, 7 Goban-cho, Chiyoda-ku, Tokyo, 102-0076, Japan
| | - Hiroshi Kitagawa
- Division of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto, 606-8502, Japan
- JST CREST, 7 Goban-cho, Chiyoda-ku, Tokyo, 102-0076, Japan
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10
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Nanophase diagram of binary eutectic Au-Ge nanoalloys for vapor-liquid-solid semiconductor nanowires growth. Sci Rep 2015; 5:11263. [PMID: 26053237 PMCID: PMC4459231 DOI: 10.1038/srep11263] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 05/20/2015] [Indexed: 11/08/2022] Open
Abstract
Although the vapor-liquid-solid growth of semiconductor nanowire is a non-equilibrium process, the equilibrium phase diagram of binary alloy provides important guidance on the growth conditions, such as the temperature and the equilibrium composition of the alloy. Given the small dimensions of the alloy seeds and the nanowires, the known phase diagram of bulk binary alloy cannot be expected to accurately predict the behavior of the nanowire growth. Here, we developed a unified model to describe the size- and dimensionality-dependent equilibrium phase diagram of Au-Ge binary eutectic nanoalloys based on the size-dependent cohesive energy model. It is found that the liquidus curves reduce and shift leftward with decreasing size and dimensionality. Moreover, the effects of size and dimensionality on the eutectic composition are small and negligible when both components in binary eutectic alloys have the same dimensionality. However, when two components have different dimensionality (e.g. Au nanoparticle-Ge nanowire usually used in the semiconductor nanowires growth), the eutectic composition reduces with decreasing size.
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Benkouider A, Ronda A, Gouyé A, Herrier C, Favre L, Lockwood DJ, Rowell NL, Delobbe A, Sudraud P, Berbezier I. Selective growth and ordering of SiGe nanowires for band gap engineering. NANOTECHNOLOGY 2014; 25:335303. [PMID: 25074329 DOI: 10.1088/0957-4484/25/33/335303] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Selective growth and self-organization of silicon-germanium (SiGe) nanowires (NWs) on focused ion beam (FIB) patterned Si(111) substrates is reported. In its first step, the process involves the selective synthesis of Au catalysts in SiO₂-free areas; its second step involves the preferential nucleation and growth of SiGe NWs on the catalysts. The selective synthesis process is based on a simple, room-temperature reduction of gold salts (Au³⁺Cl₄⁻) in aqueous solution, which provides well-organized Au catalysts. By optimizing the reduction process, we are able to generate a bidimensional regular array of Au catalysts with self-limited sizes positioned in SiO₂-free windows opened in a SiO₂/Si(111) substrate by FIB patterning. Such Au catalysts subsequently serve as preferential nucleation and growth sites of well-organized NWs. Furthermore, these NWs with tunable position and size exhibit the relevant features and bright luminescence that would find several applications in optoelectronic nanodevices.
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Affiliation(s)
- A Benkouider
- CNRS, Aix-Marseille University, IM2NP, 13397 Marseille Cedex 20, France
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Gamalski AD, Tersoff J, Sharma R, Ducati C, Hofmann S. Metastable crystalline AuGe catalysts formed during isothermal germanium nanowire growth. PHYSICAL REVIEW LETTERS 2012; 108:255702. [PMID: 23004621 DOI: 10.1103/physrevlett.108.255702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Indexed: 06/01/2023]
Abstract
We observe the formation of metastable AuGe phases without quenching, during strictly isothermal nucleation and growth of Ge nanowires, using video-rate lattice-resolved environmental transmission electron microscopy. We explain the unexpected formation of these phases through a novel pathway involving changes in composition rather than temperature. The metastable catalyst has important implications for nanowire growth, and more broadly, the isothermal process provides both a new approach to growing and studying metastable phases, and a new perspective on their formation.
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Affiliation(s)
- A D Gamalski
- Department of Engineering, University of Cambridge, Cambridge CB3 0FA, United Kingdom.
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13
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Huang X, Li S, Huang Y, Wu S, Zhou X, Li S, Gan CL, Boey F, Mirkin CA, Zhang H. Synthesis of hexagonal close-packed gold nanostructures. Nat Commun 2011; 2:292. [DOI: 10.1038/ncomms1291] [Citation(s) in RCA: 484] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Accepted: 03/25/2011] [Indexed: 11/09/2022] Open
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14
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Yuan FW, Yang HJ, Tuan HY. Seeded silicon nanowire growth catalyzed by commercially available bulk metals: broad selection of metal catalysts, superior field emission performance, and versatile nanowire/metal architectures. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1jm11956g] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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