1
|
Hettler S, Furqan M, Arenal R. Support-Based Transfer and Contacting of Individual Nanomaterials for In Situ Nanoscale Investigations. SMALL METHODS 2024:e2400034. [PMID: 38470226 DOI: 10.1002/smtd.202400034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 02/22/2024] [Indexed: 03/13/2024]
Abstract
Although in situ transmission electron microscopy (TEM) of nanomaterials has been gaining importance in recent years, difficulties in sample preparation have limited the number of studies on electrical properties. Here, a support-based preparation method of individual 1D and 2D materials is presented, which yields a reproducible sample transfer for electrical investigation by in situ TEM. A mechanically rigid support grid facilitates the transfer and contacting to in situ chips by focused ion beam with minimum damage and contamination. The transfer quality is assessed by exemplary specimens of different nanomaterials, including a monolayer of WS2 . Possible studies concern the interplay between structural properties and electrical characteristics on the individual nanomaterial level as well as failure analysis under electrical current or studies of electromigration, Joule heating, and related effects. The TEM measurements can be enriched by additional correlative microscopy and spectroscopy carried out on the identical object with techniques that allow a characterization with a spatial resolution in the range of a few microns. Although developed for in situ TEM, the present transfer method is also applicable to transferring nanomaterials to similar chips for performing further studies or even for using them in potential electrical/optoelectronic/sensing devices.
Collapse
Affiliation(s)
- Simon Hettler
- Laboratorio de Microscopías Avanzadas (LMA), Universidad de Zaragoza, Zaragoza, 50018, Spain
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Zaragoza, 50009, Spain
| | - Mohammad Furqan
- Laboratorio de Microscopías Avanzadas (LMA), Universidad de Zaragoza, Zaragoza, 50018, Spain
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Zaragoza, 50009, Spain
| | - Raul Arenal
- Laboratorio de Microscopías Avanzadas (LMA), Universidad de Zaragoza, Zaragoza, 50018, Spain
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Zaragoza, 50009, Spain
- ARAID Foundation, Zaragoza, 50018, Spain
| |
Collapse
|
2
|
Vogl LM, Kalancha V, Schweizer P, Denninger P, Wu M, Brabec C, Forberich K, Spiecker E. Influence of tin oxide decoration on the junction conductivity of silver nanowires. NANOTECHNOLOGY 2023; 34:175706. [PMID: 36649645 DOI: 10.1088/1361-6528/acb3ca] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 01/17/2023] [Indexed: 06/17/2023]
Abstract
Flexible electrodes using nanowires (NWs) suffer from challenges of long-term stability and high junction resistance which limit their fields of applications. Welding via thermal annealing is a common strategy to enhance the conductivity of percolated NW networks, however, it affects the structural and mechanical integrity of the NWs. In this study we show that the decoration of NWs with an ultrathin metal oxide is a potential alternative procedure which not only enhances the thermal and chemical stability but, moreover, provides a totally different mechanism to reduce the junction resistance upon heat treatment. Here, we analyze the effect of SnOxdecoration on the conductance of silver NWs and NW junctions by using a four-probe measurement setup inside a scanning electron microscope. Dedicated transmission electron microscopy analysis in plan-view and cross-section geometry are carried out to characterize the nanowires and the microstructure of the junctions. Upon heat treatment the junction resistance of both plain silver NWs and SnOx-decorated NWs is reduced by around 80%. While plain silver NWs show characteristic junction welding during annealing, the SnOx-decoration reduces junction resistance by a solder-like process which does not affect the mechanical integrity of the NW junction and is therefore expected to be superior for applications.
Collapse
Affiliation(s)
- Lilian Maria Vogl
- Institute of Micro-and Nanostructure Research (IMN), Center for Nanoanalysis and Electron Microscopy (CENEM), Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
| | - Violetta Kalancha
- Institute Materials for Electronics and Energy Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
| | - Peter Schweizer
- Institute of Micro-and Nanostructure Research (IMN), Center for Nanoanalysis and Electron Microscopy (CENEM), Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
| | - Peter Denninger
- Institute of Micro-and Nanostructure Research (IMN), Center for Nanoanalysis and Electron Microscopy (CENEM), Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
| | - Mingjian Wu
- Institute of Micro-and Nanostructure Research (IMN), Center for Nanoanalysis and Electron Microscopy (CENEM), Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
| | - Christoph Brabec
- Institute Materials for Electronics and Energy Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
| | - Karen Forberich
- Institute Materials for Electronics and Energy Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
- Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (IEK-11), Erlangen, Germany
| | - Erdmann Spiecker
- Institute of Micro-and Nanostructure Research (IMN), Center for Nanoanalysis and Electron Microscopy (CENEM), Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
| |
Collapse
|
3
|
Johnson BC, Stuiber M, Creedon DL, Bose M, Berhane A, Willems van Beveren LH, Rubanov S, Cole JH, Mourik V, Hamilton AR, Duty TL, McCallum JC. Silicon-Aluminum Phase-Transformation-Induced Superconducting Rings. NANO LETTERS 2023; 23:17-24. [PMID: 36573935 DOI: 10.1021/acs.nanolett.2c02814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The development of devices that exhibit both superconducting and semiconducting properties is an important endeavor for emerging quantum technologies. We investigate superconducting nanowires fabricated on a silicon-on-insulator (SOI) platform. Aluminum from deposited contact electrodes is found to interdiffuse with Si along the entire length of the nanowire, over micrometer length scales and at temperatures well below the Al-Si eutectic. The phase-transformed material is conformal with the predefined device patterns. The superconducting properties of a transformed mesoscopic ring formed on a SOI platform are investigated. Low-temperature magnetoresistance oscillations, quantized in units of the fluxoid, h/2e, are observed.
Collapse
Affiliation(s)
- Brett C Johnson
- School of Science, RMIT University, Melbourne, Victoria3001, Australia
| | - Michael Stuiber
- Melbourne Centre for Nanofabrication, Clayton, Victoria3168, Australia
| | - Daniel L Creedon
- School of Physics, University of Melbourne, Parkville, Victoria3010, Australia
| | - Manjith Bose
- School of Physics, University of Melbourne, Parkville, Victoria3010, Australia
| | - Amanuel Berhane
- School of Physics, University of New South Wales, Sydney, New South Wales1466, Australia
| | | | - Sergey Rubanov
- Ian Holmes Imaging Centre, Bio21 Institute, University of Melbourne, Parkville, Victoria3010, Australia
| | - Jared H Cole
- School of Science, RMIT University, Melbourne, Victoria3001, Australia
| | - Vincent Mourik
- School of Physics, University of New South Wales, Sydney, New South Wales1466, Australia
| | - Alexander R Hamilton
- School of Physics, University of New South Wales, Sydney, New South Wales1466, Australia
| | - Timothy L Duty
- School of Physics, University of New South Wales, Sydney, New South Wales1466, Australia
| | | |
Collapse
|
4
|
Roy KS, Hettler S, Arenal R, Panchakarla LS. Strontium-deficient Sr xCoO 2-CoO 2 nanotubes as a high ampacity and high conductivity material. MATERIALS HORIZONS 2022; 9:2115-2127. [PMID: 35766405 DOI: 10.1039/d1mh01987b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Continuous miniaturization of electronics demands the development of interconnectors with high ampacity and high conductivity, which conventional conductors such as copper and gold cannot offer. Here we report the synthesis of Sr-deficient misfit SrxCoO2-CoO2 nanotubes by a novel crystal conversion method and investigate their electrical properties. Bulk Sr6Co5O15 having a quasi-one-dimensional CoO6 polyhedral structure (face-sharing octahedron and trigonal prismatic CoO6 arranged in one-dimension) is converted to SrxCoO2-CoO2 nanotubes where CoO2 adopts a two-dimensional edge-sharing CoO2 layered structure in a basic hydrothermal process. Electrical properties measured on individual nanotubes demonstrate that these nanotubes are semiconducting with a conductivity of 1.28 × 104 S cm-1 and an ampacity of 109 A cm-2, which is the highest reported ampacity value to date of any inorganic oxide-based material. The nanotubes also show a breakdown power per unit channel length (P/L) of ∼38.3 W cm-1, the highest among the regularly used interconnect materials. The above results demonstrate that SrxCoO2-CoO2 nanotubes are potential building blocks for high-power electronic applications.
Collapse
Affiliation(s)
- Kankona Singha Roy
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Simon Hettler
- Instituto de Nanociencia y Materiales de Aragon (INMA), CSIC-Universidad de Zaragoza, Calle Pedro Cerbuna 12, 50009 Zaragoza, Spain.
- Laboratorio de Microscopias Avanzadas (LMA), Universidad de Zaragoza, Calle Mariano Esquillor, 50018 Zaragoza, Spain
| | - Raul Arenal
- Instituto de Nanociencia y Materiales de Aragon (INMA), CSIC-Universidad de Zaragoza, Calle Pedro Cerbuna 12, 50009 Zaragoza, Spain.
- Laboratorio de Microscopias Avanzadas (LMA), Universidad de Zaragoza, Calle Mariano Esquillor, 50018 Zaragoza, Spain
- ARAID Foundation, 50018 Zaragoza, Spain
| | - Leela S Panchakarla
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| |
Collapse
|
5
|
Tarasevich YY, Vodolazskaya IV, Eserkepov AV. Electrical conductivity of random metallic nanowire networks: an analytical consideration along with computer simulation. Phys Chem Chem Phys 2022; 24:11812-11819. [PMID: 35507328 DOI: 10.1039/d2cp00936f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The current interest in the study of the 2D systems of randomly deposited metallic nanowires is inspired by a combination of their high electrical conductivity with excellent optical transparency. Metallic nanowire networks show great potential for use in numerous technological applications. Although there are models that describe the electrical conductivity of the random nanowire networks through wire resistance, junction resistance, and number density of nanowires, they are either not rigorously justified or contain fitting parameters. We have proposed a model for the electrical conductivity in random metallic nanowire networks. We have mimicked such random nanowire networks as random resistor networks (RRN) produced by the homogeneous, isotropic, and random deposition of conductive zero-width sticks onto an insulating substrate. We studied the electrical conductivity of these RRNs using a mean-field approximation. An analytical dependency of the electrical conductivity on the main physical parameters (the number density and electrical resistances of these wires and of the junctions between them) has been derived. Computer simulations have been performed to validate our theoretical predictions. We computed the electrical conductivity of the RRNs against the number density of the conductive fillers for the junction-resistance-dominated case and for the case where the wire resistance and the junction resistance were equal. The results of the computations were compared with this mean-field approximation. Our computations demonstrated that our analytical expression correctly predicts the electrical conductivity across a wide range of number densities.
Collapse
Affiliation(s)
- Yuri Yu Tarasevich
- Laboratory of Mathematical Modeling, Astrakhan State University, Astrakhan 414056, Russia.
| | - Irina V Vodolazskaya
- Laboratory of Mathematical Modeling, Astrakhan State University, Astrakhan 414056, Russia.
| | - Andrei V Eserkepov
- Laboratory of Mathematical Modeling, Astrakhan State University, Astrakhan 414056, Russia.
| |
Collapse
|
6
|
Sistani M, Böckle R, Falkensteiner D, Luong MA, den Hertog MI, Lugstein A, Weber WM. Nanometer-Scale Ge-Based Adaptable Transistors Providing Programmable Negative Differential Resistance Enabling Multivalued Logic. ACS NANO 2021; 15:18135-18141. [PMID: 34705418 DOI: 10.1021/acsnano.1c06801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The functional diversification and adaptability of the elementary switching units of computational circuits are disruptive approaches for advancing electronics beyond the static capabilities of conventional complementary metal-oxide-semiconductor-based architectures. Thereto, in this work the one-dimensional nature of monocrystalline and monolithic Al-Ge-based nanowire heterostructures is exploited to deliver charge carrier polarity control and furthermore to enable distinct programmable negative differential resistance at runtime. The fusion of electron and hole conduction together with negative differential resistance in a universal adaptive transistor may enable energy-efficient reconfigurable circuits with multivalued operability that are inherent components of emerging artificial intelligence electronics.
Collapse
Affiliation(s)
- Masiar Sistani
- Institute of Solid State Electronics, TU Wien, 1040 Vienna, Austria
| | - Raphael Böckle
- Institute of Solid State Electronics, TU Wien, 1040 Vienna, Austria
| | | | - Minh Anh Luong
- University Grenoble Alpes, CEA, IRIG-DEPHY-MEM-LEMMA, F-38000 Grenoble, France
| | | | - Alois Lugstein
- Institute of Solid State Electronics, TU Wien, 1040 Vienna, Austria
| | - Walter M Weber
- Institute of Solid State Electronics, TU Wien, 1040 Vienna, Austria
| |
Collapse
|
7
|
Delaforce J, Sistani M, Kramer RBG, Luong MA, Roch N, Weber WM, den Hertog MI, Robin E, Naud C, Lugstein A, Buisson O. Al-Ge-Al Nanowire Heterostructure: From Single-Hole Quantum Dot to Josephson Effect. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2101989. [PMID: 34365674 DOI: 10.1002/adma.202101989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/31/2021] [Indexed: 06/13/2023]
Abstract
Superconductor-semiconductor-superconductor heterostructures are attractive for both fundamental studies of quantum phenomena in low-dimensional hybrid systems as well as for future high-performance low power dissipating nanoelectronic and quantum devices. In this work, ultrascaled monolithic Al-Ge-Al nanowire heterostructures featuring monocrystalline Al leads and abrupt metal-semiconductor interfaces are used to probe the low-temperature transport in intrinsic Ge (i-Ge) quantum dots. In particular, demonstrating the ability to tune the Ge quantum dot device from completely insulating, through a single-hole-filling quantum dot regime, to a supercurrent regime, resembling a Josephson field effect transistor with a maximum critical current of 10 nA at a temperature of 390 mK. The realization of a Josephson field-effect transistor with high junction transparency provides a mechanism to study sub-gap transport mediated by Andreev states. The presented results reveal a promising intrinsic Ge-based architecture for hybrid superconductor-semiconductor devices for the study of Majorana zero modes and key components of quantum computing such as gatemons or gate tunable superconducting quantum interference devices.
Collapse
Affiliation(s)
- Jovian Delaforce
- Institut NEEL UPR2940, Université Grenoble Alpes, CNRS, Grenoble, 38042, France
| | - Masiar Sistani
- Institute of Solid State Electronics, TU Wien, Gußhausstraße 25-25a, Vienna, 1040, Austria
| | - Roman B G Kramer
- Institut NEEL UPR2940, Université Grenoble Alpes, CNRS, Grenoble, 38042, France
| | - Minh A Luong
- Université Grenoble Alpes, CEA, IRIG-DEPHY, F-38054, Grenoble, 38054, France
| | - Nicolas Roch
- Institut NEEL UPR2940, Université Grenoble Alpes, CNRS, Grenoble, 38042, France
| | - Walter M Weber
- Institute of Solid State Electronics, TU Wien, Gußhausstraße 25-25a, Vienna, 1040, Austria
| | | | - Eric Robin
- Université Grenoble Alpes, CEA, IRIG-DEPHY, F-38054, Grenoble, 38054, France
| | - Cecile Naud
- Institut NEEL UPR2940, Université Grenoble Alpes, CNRS, Grenoble, 38042, France
| | - Alois Lugstein
- Institute of Solid State Electronics, TU Wien, Gußhausstraße 25-25a, Vienna, 1040, Austria
| | - Olivier Buisson
- Institut NEEL UPR2940, Université Grenoble Alpes, CNRS, Grenoble, 38042, France
| |
Collapse
|
8
|
Luong MA, Robin E, Pauc N, Gentile P, Baron T, Salem B, Sistani M, Lugstein A, Spies M, Fernandez B, den Hertog M. Reversible Al Propagation in Si x Ge 1-x Nanowires: Implications for Electrical Contact Formation. ACS APPLIED NANO MATERIALS 2020; 3:10427-10436. [PMID: 33134884 PMCID: PMC7589613 DOI: 10.1021/acsanm.0c02303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 09/16/2020] [Indexed: 06/11/2023]
Abstract
While reversibility is a fundamental concept in thermodynamics, most reactions are not readily reversible, especially in solid-state physics. For example, thermal diffusion is a widely known concept, used among others to inject dopants into the substitutional positions in the matrix and improve device properties. Typically, such a diffusion process will create a concentration gradient extending over increasingly large regions, without possibility to reverse this effect. On the other hand, while the bottom-up growth of semiconducting nanowires is interesting, it can still be difficult to fabricate axial heterostructures with high control. In this paper, we report a thermally assisted partially reversible thermal diffusion process occurring in the solid-state reaction between an Al metal pad and a Si x Ge1-x alloy nanowire observed by in situ transmission electron microscopy. The thermally assisted reaction results in the creation of a Si-rich region sandwiched between the reacted Al and unreacted Si x Ge1-x part, forming an axial Al/Si/Si x Ge1-x heterostructure. Upon heating or (slow) cooling, the Al metal can repeatably move in and out of the Si x Ge1-x alloy nanowire while maintaining the rodlike geometry and crystallinity, allowing to fabricate and contact nanowire heterostructures in a reversible way in a single process step, compatible with current Si-based technology. This interesting system is promising for various applications, such as phase change memories in an all crystalline system with integrated contacts as well as Si/Si x Ge1-x /Si heterostructures for near-infrared sensing applications.
Collapse
Affiliation(s)
- Minh Anh Luong
- CEA-Grenoble,
IRIG-DEPHY-MEM-LEMMA, Université
Grenoble Alpes, F-38054 Grenoble, France
| | - Eric Robin
- CEA-Grenoble,
IRIG-DEPHY-MEM-LEMMA, Université
Grenoble Alpes, F-38054 Grenoble, France
| | - Nicolas Pauc
- CEA-Grenoble,
IRIG-DEPHY-PHELIQS-SINAPS, Université
Grenoble Alpes, F-38000 Grenoble, France
| | - Pascal Gentile
- CEA-Grenoble,
IRIG-DEPHY-PHELIQS-SINAPS, Université
Grenoble Alpes, F-38000 Grenoble, France
| | - Thierry Baron
- CNRS,
LTM, Université Grenoble Alpes, 38054 Grenoble, France
| | - Bassem Salem
- CNRS,
LTM, Université Grenoble Alpes, 38054 Grenoble, France
| | - Masiar Sistani
- Institute
of Solid State Electronics, Technische Universität
Wien, Gußhausstraße 25-25a, Vienna 1040, Austria
| | - Alois Lugstein
- Institute
of Solid State Electronics, Technische Universität
Wien, Gußhausstraße 25-25a, Vienna 1040, Austria
| | - Maria Spies
- CNRS,
Institut NEEL UPR2940, Université
Grenoble Alpes, 25 Avenue des Martyrs, Grenoble 38042, France
| | - Bruno Fernandez
- CNRS,
Institut NEEL UPR2940, Université
Grenoble Alpes, 25 Avenue des Martyrs, Grenoble 38042, France
| | - Martien den Hertog
- CNRS,
Institut NEEL UPR2940, Université
Grenoble Alpes, 25 Avenue des Martyrs, Grenoble 38042, France
| |
Collapse
|
9
|
Gächter N, Könemann F, Sistani M, Bartmann MG, Sousa M, Staudinger P, Lugstein A, Gotsmann B. Spatially resolved thermoelectric effects in operando semiconductor-metal nanowire heterostructures. NANOSCALE 2020; 12:20590-20597. [PMID: 33030483 DOI: 10.1039/d0nr05504b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The thermoelectric properties of a nanoscale germanium segment connected by aluminium nanowires are studied using scanning thermal microscopy. The germanium segment of 168 nm length features atomically sharp interfaces to the aluminium wires and is surrounded by an Al2O3 shell. The temperature distribution along the self-heated nanowire is measured as a function of the applied electrical current, for both Joule and Peltier effects. An analysis is developed that is able to extract the thermal and thermoelectric properties including thermal conductivity, the thermal boundary resistance to the substrate and the Peltier coefficient from a single measurement. Our investigations demonstrate the potential of quantitative measurements of temperature around self-heated devices and structures down to the scattering length of heat carriers.
Collapse
Affiliation(s)
| | | | - Masiar Sistani
- Institute of Solid State Electronics - TU Wien, 1040 Vienna, Austria
| | | | | | | | - Alois Lugstein
- Institute of Solid State Electronics - TU Wien, 1040 Vienna, Austria
| | | |
Collapse
|
10
|
Sistani M, Staudinger P, Lugstein A. Polarity Control in Ge Nanowires by Electronic Surface Doping. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2020; 124:19858-19863. [PMID: 32952775 PMCID: PMC7497402 DOI: 10.1021/acs.jpcc.0c05749] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/12/2020] [Indexed: 06/11/2023]
Abstract
The performance of nanoscale electronic and photonic devices critically depends on the size and geometry and may significantly differ from those of their bulk counterparts. Along with confinement effects, the inherently high surface-to-volume ratio of nanostructures causes their properties to strongly depend on the surface. With a high and almost symmetric electron and hole mobility, Ge is considered to be a key material extending device performances beyond the limits imposed by miniaturization. Nevertheless, the deleterious effects of charge trapping are still a severe limiting factor for applications of Ge-based nanoscale devices. In this work, we show exemplarily for Ge nanowires that controlling the surface trap population by electrostatic gating can be utilized for effective surface doping. The reproducible transition from hole- to electron-dominated transport is clearly demonstrated by the observation of electron-driven negative differential resistance and provides a significant step towards a better understanding of charge-trapping-induced transport in Ge nanostructures.
Collapse
|
11
|
Firestein KL, Kvashnin DG, Fernando JFS, Zhang C, Siriwardena DP, Sorokin PB, Golberg DV. Crystallography-Derived Young's Modulus and Tensile Strength of AlN Nanowires as Revealed by in Situ Transmission Electron Microscopy. NANO LETTERS 2019; 19:2084-2091. [PMID: 30786716 DOI: 10.1021/acs.nanolett.9b00263] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Aluminum nitride (AlN) has a unique combination of properties, such as high chemical and thermal stability, nontoxicity, high melting point, large energy band gap, high thermal conductivity, and intensive light emission. This combination makes AlN nanowires (NWs) a prospective material for optoelectronic and field-emission nanodevices. However, there has been very limited information on mechanical properties of AlN NWs that is essential for their reliable utilization in modern technologies. Herein, we thoroughly study mechanical properties of individual AlN NWs using direct, in situ bending and tensile tests inside a high-resolution TEM. Overall, 22 individual NWs have been tested, and a strong dependence of their Young's moduli and ultimate tensile strengths (UTS) on their growth axis crystallographic orientation is documented. The Young's modulus of NWs grown along the [101̅1] orientation is found to be in a range 160-260 GPa, whereas for those grown along the [0002] orientation it falls within a range 350-440 GPa. In situ TEM tensile tests demonstrate the UTS values up to 8.2 GPa for the [0002]-oriented NWs, which is more than 20 times larger than that of a bulk AlN compound. Such properties make AlN nanowires a highly promising material for the reinforcing applications in metal matrix and other composites. Finally, experimental results were compared and verified under a density functional theory simulation, which shows the pronounced effect of growth axis on the AlN NW mechanical behavior. The modeling reveals that with an increasing NW width the Young's modulus tends to approach the elastic constants of a bulk material.
Collapse
Affiliation(s)
- Konstantin L Firestein
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty , Queensland University of Technology (QUT) , 2nd George str. , Brisbane , Queensland 4000 , Australia
| | - Dmitry G Kvashnin
- National University of Science and Technology "MISiS" , Leninskiy Prospekt 4 , Moscow 119049 , Russian Federation
- Emanuel Institute of Biochemical Physics , Russian Academy of Sciences , Kosigina Street 4 , Moscow 119334 , Russian Federation
| | - Joseph F S Fernando
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty , Queensland University of Technology (QUT) , 2nd George str. , Brisbane , Queensland 4000 , Australia
| | - Chao Zhang
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty , Queensland University of Technology (QUT) , 2nd George str. , Brisbane , Queensland 4000 , Australia
| | - Dumindu P Siriwardena
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty , Queensland University of Technology (QUT) , 2nd George str. , Brisbane , Queensland 4000 , Australia
| | - Pavel B Sorokin
- National University of Science and Technology "MISiS" , Leninskiy Prospekt 4 , Moscow 119049 , Russian Federation
- Emanuel Institute of Biochemical Physics , Russian Academy of Sciences , Kosigina Street 4 , Moscow 119334 , Russian Federation
- Technological Institute for Superhard and Novel Carbon Materials , Centralnaya Street 7a , Troitsk 108840 , Russian Federation
| | - Dmitri V Golberg
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty , Queensland University of Technology (QUT) , 2nd George str. , Brisbane , Queensland 4000 , Australia
- International Center for Materials Nanoarchitectonics (MANA) , National Institute for Materials Science (NIMS) , Namiki 1-1 , Tsukuba , Ibaraki 3050044 , Japan
| |
Collapse
|