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Panasci SE, Deretzis I, Schilirò E, La Magna A, Roccaforte F, Koos A, Nemeth M, Pécz B, Cannas M, Agnello S, Giannazzo F. Interface Properties of MoS 2 van der Waals Heterojunctions with GaN. Nanomaterials (Basel) 2024; 14:133. [PMID: 38251098 PMCID: PMC10818867 DOI: 10.3390/nano14020133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/27/2023] [Accepted: 01/03/2024] [Indexed: 01/23/2024]
Abstract
The combination of the unique physical properties of molybdenum disulfide (MoS2) with those of gallium nitride (GaN) and related group-III nitride semiconductors have recently attracted increasing scientific interest for the realization of innovative electronic and optoelectronic devices. A deep understanding of MoS2/GaN interface properties represents the key to properly tailor the electronic and optical behavior of devices based on this heterostructure. In this study, monolayer (1L) MoS2 was grown on GaN-on-sapphire substrates by chemical vapor deposition (CVD) at 700 °C. The structural, chemical, vibrational, and light emission properties of the MoS2/GaN heterostructure were investigated in detail by the combination of microscopic/spectroscopic techniques and ab initio calculations. XPS analyses on as-grown samples showed the formation of stoichiometric MoS2. According to micro-Raman spectroscopy, monolayer MoS2 domains on GaN exhibit an average n-type doping of (0.11 ± 0.12) × 1013 cm-2 and a small tensile strain (ε ≈ 0.25%), whereas an intense light emission at 1.87 eV was revealed by PL analyses. Furthermore, a gap at the interface was shown by cross-sectional TEM analysis, confirming the van der Waals (vdW) bond between MoS2 and GaN. Finally, density functional theory (DFT) calculations of the heterostructure were carried out, considering three different configurations of the interface, i.e., (i) an ideal Ga-terminated GaN surface, (ii) the passivation of Ga surface by a monolayer of oxygen (O), and (iii) the presence of an ultrathin Ga2O3 layer. This latter model predicts the formation of a vdW interface and a strong n-type doping of MoS2, in closer agreement with the experimental observations.
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Affiliation(s)
- Salvatore Ethan Panasci
- National Research Council-Institute for Microelectronics and Microsystems (CNR-IMM), Z.I. Strada VIII 5, 95121 Catania, Italy; (I.D.); (E.S.); (A.L.M.); (F.R.); (S.A.); (F.G.)
| | - Ioannis Deretzis
- National Research Council-Institute for Microelectronics and Microsystems (CNR-IMM), Z.I. Strada VIII 5, 95121 Catania, Italy; (I.D.); (E.S.); (A.L.M.); (F.R.); (S.A.); (F.G.)
| | - Emanuela Schilirò
- National Research Council-Institute for Microelectronics and Microsystems (CNR-IMM), Z.I. Strada VIII 5, 95121 Catania, Italy; (I.D.); (E.S.); (A.L.M.); (F.R.); (S.A.); (F.G.)
| | - Antonino La Magna
- National Research Council-Institute for Microelectronics and Microsystems (CNR-IMM), Z.I. Strada VIII 5, 95121 Catania, Italy; (I.D.); (E.S.); (A.L.M.); (F.R.); (S.A.); (F.G.)
| | - Fabrizio Roccaforte
- National Research Council-Institute for Microelectronics and Microsystems (CNR-IMM), Z.I. Strada VIII 5, 95121 Catania, Italy; (I.D.); (E.S.); (A.L.M.); (F.R.); (S.A.); (F.G.)
| | - Antal Koos
- HUN-REN Centre for Energy Research, Institute of Technical Physics and Materials Science, Konkoly-Thege ut 29-33, 1121 Budapest, Hungary; (A.K.); (M.N.)
| | - Miklos Nemeth
- HUN-REN Centre for Energy Research, Institute of Technical Physics and Materials Science, Konkoly-Thege ut 29-33, 1121 Budapest, Hungary; (A.K.); (M.N.)
| | - Béla Pécz
- HUN-REN Centre for Energy Research, Institute of Technical Physics and Materials Science, Konkoly-Thege ut 29-33, 1121 Budapest, Hungary; (A.K.); (M.N.)
| | - Marco Cannas
- Department of Physics and Chemistry Emilio Segrè, University of Palermo, Via Archirafi 36, 90123 Palermo, Italy;
| | - Simonpietro Agnello
- National Research Council-Institute for Microelectronics and Microsystems (CNR-IMM), Z.I. Strada VIII 5, 95121 Catania, Italy; (I.D.); (E.S.); (A.L.M.); (F.R.); (S.A.); (F.G.)
- Department of Physics and Chemistry Emilio Segrè, University of Palermo, Via Archirafi 36, 90123 Palermo, Italy;
- ATEN Center, University of Palermo, Viale delle Scienze Ed. 18, 90128 Palermo, Italy
| | - Filippo Giannazzo
- National Research Council-Institute for Microelectronics and Microsystems (CNR-IMM), Z.I. Strada VIII 5, 95121 Catania, Italy; (I.D.); (E.S.); (A.L.M.); (F.R.); (S.A.); (F.G.)
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Španková M, Chromik Š, Dobročka E, Pribusová Slušná L, Talacko M, Gregor M, Pécz B, Koos A, Greco G, Panasci SE, Fiorenza P, Roccaforte F, Cordier Y, Frayssinet E, Giannazzo F. Large-Area MoS 2 Films Grown on Sapphire and GaN Substrates by Pulsed Laser Deposition. Nanomaterials (Basel) 2023; 13:2837. [PMID: 37947682 PMCID: PMC10647872 DOI: 10.3390/nano13212837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 10/19/2023] [Accepted: 10/24/2023] [Indexed: 11/12/2023]
Abstract
In this paper, we present the preparation of few-layer MoS2 films on single-crystal sapphire, as well as on heteroepitaxial GaN templates on sapphire substrates, using the pulsed laser deposition (PLD) technique. Detailed structural and chemical characterization of the films were performed using Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction measurements, and high-resolution transmission electron microscopy. According to X-ray diffraction studies, the films exhibit epitaxial growth, indicating a good in-plane alignment. Furthermore, the films demonstrate uniform thickness on large areas, as confirmed by Raman spectroscopy. The lateral electrical current transport of the MoS2 grown on sapphire was investigated by temperature (T)-dependent sheet resistance and Hall effect measurements, showing a high n-type doping of the semiconducting films (ns from ~1 × 1013 to ~3.4 × 1013 cm-2 from T = 300 K to 500 K), with a donor ionization energy of Ei = 93 ± 8 meV and a mobility decreasing with T. Finally, the vertical current injection across the MoS2/GaN heterojunction was investigated by means of conductive atomic force microscopy, showing the rectifying behavior of the I-V characteristics with a Schottky barrier height of ϕB ≈ 0.36 eV. The obtained results pave the way for the scalable application of PLD-grown MoS2 on GaN in electronics/optoelectronics.
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Affiliation(s)
- Marianna Španková
- Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, 84104 Bratislava, Slovakia; (Š.C.); (E.D.); (L.P.S.); (M.T.)
| | - Štefan Chromik
- Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, 84104 Bratislava, Slovakia; (Š.C.); (E.D.); (L.P.S.); (M.T.)
| | - Edmund Dobročka
- Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, 84104 Bratislava, Slovakia; (Š.C.); (E.D.); (L.P.S.); (M.T.)
| | - Lenka Pribusová Slušná
- Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, 84104 Bratislava, Slovakia; (Š.C.); (E.D.); (L.P.S.); (M.T.)
| | - Marcel Talacko
- Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, 84104 Bratislava, Slovakia; (Š.C.); (E.D.); (L.P.S.); (M.T.)
| | - Maroš Gregor
- Faculty of Mathematics, Physics and Informatics, Comenius University Bratislava, 84248 Bratislava, Slovakia;
| | - Béla Pécz
- HUN-REN Centre for Energy Research, Institute of Technical Physics and Materials Science, Konkoly-Thege ut 29-33, 1121 Budapest, Hungary; (B.P.); (A.K.)
| | - Antal Koos
- HUN-REN Centre for Energy Research, Institute of Technical Physics and Materials Science, Konkoly-Thege ut 29-33, 1121 Budapest, Hungary; (B.P.); (A.K.)
| | - Giuseppe Greco
- Consiglio Nazionale delle Ricerche—Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII 5, 95121 Catania, Italy; (G.G.); (S.E.P.); (P.F.); (F.R.); (F.G.)
| | - Salvatore Ethan Panasci
- Consiglio Nazionale delle Ricerche—Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII 5, 95121 Catania, Italy; (G.G.); (S.E.P.); (P.F.); (F.R.); (F.G.)
| | - Patrick Fiorenza
- Consiglio Nazionale delle Ricerche—Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII 5, 95121 Catania, Italy; (G.G.); (S.E.P.); (P.F.); (F.R.); (F.G.)
| | - Fabrizio Roccaforte
- Consiglio Nazionale delle Ricerche—Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII 5, 95121 Catania, Italy; (G.G.); (S.E.P.); (P.F.); (F.R.); (F.G.)
| | - Yvon Cordier
- CNRS, CRHEA, Université Côte d’Azur, 06560 Valbonne, France; (Y.C.); (E.F.)
| | - Eric Frayssinet
- CNRS, CRHEA, Université Côte d’Azur, 06560 Valbonne, France; (Y.C.); (E.F.)
| | - Filippo Giannazzo
- Consiglio Nazionale delle Ricerche—Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII 5, 95121 Catania, Italy; (G.G.); (S.E.P.); (P.F.); (F.R.); (F.G.)
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Lábár JL, Pécz B, van Waveren A, Hallais G, Desvignes L, Chiodi F. Strain Measurement in Single Crystals by 4D-ED. Nanomaterials (Basel) 2023; 13:1007. [PMID: 36985899 PMCID: PMC10054437 DOI: 10.3390/nano13061007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/01/2023] [Accepted: 03/06/2023] [Indexed: 06/18/2023]
Abstract
A new method is presented to measure strain over a large area of a single crystal. The 4D-ED data are collected by recording a 2D diffraction pattern at each position in the 2D area of the TEM lamella scanned by the electron beam of STEM. Data processing is completed with a new computer program (available free of charge) that runs under the Windows operating system. Previously published similar methods are either commercial or need special hardware (electron holography) or are based on HRTEM, which involves limitations with respect to the size of the field of view. All these limitations are overcome by our approach. The presence of defects results in small local changes in orientation that change the subset of experimentally available diffraction spots in the individual patterns. Our method is based on a new principle, namely fitting a lattice to (a subset of) measured diffraction spots to improve the precision of the measurement. Although a spot to be measured may be missing in some of the patterns even the missing spot can be precisely measured by the lattice determined from the available spots. Application is exemplified by heavily boron-doped silicon with intended usage as a low-temperature superconductor in qubits.
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Affiliation(s)
- János L. Lábár
- Thin Film Physics Laboratory, Institute of Technical Physics and Materials Science, Centre of Energy Research, Konkoly Thege M. u. 29-33, H-1121 Budapest, Hungary;
| | - Béla Pécz
- Thin Film Physics Laboratory, Institute of Technical Physics and Materials Science, Centre of Energy Research, Konkoly Thege M. u. 29-33, H-1121 Budapest, Hungary;
| | - Aiken van Waveren
- Centre de Nanosciences et de Nanotechnologies—C2N, Université Paris-Saclay, CNRS, 91120 Palaiseau, France (F.C.)
| | - Géraldine Hallais
- Centre de Nanosciences et de Nanotechnologies—C2N, Université Paris-Saclay, CNRS, 91120 Palaiseau, France (F.C.)
| | - Léonard Desvignes
- Centre de Nanosciences et de Nanotechnologies—C2N, Université Paris-Saclay, CNRS, 91120 Palaiseau, France (F.C.)
| | - Francesca Chiodi
- Centre de Nanosciences et de Nanotechnologies—C2N, Université Paris-Saclay, CNRS, 91120 Palaiseau, France (F.C.)
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Peter B, Kanyo N, Kovacs KD, Kovács V, Szekacs I, Pécz B, Molnár K, Nakanishi H, Lagzi I, Horvath R. Glycocalyx Components Detune the Cellular Uptake of Gold Nanoparticles in a Size- and Charge-Dependent Manner. ACS Appl Bio Mater 2022; 6:64-73. [PMID: 36239448 PMCID: PMC9846697 DOI: 10.1021/acsabm.2c00595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Functionalized nanoparticles (NPs) are widely used in targeted drug delivery and biomedical imaging due to their penetration into living cells. The outer coating of most cells is a sugar-rich layer of the cellular glycocalyx, presumably playing an important part in any uptake processes. However, the exact role of the cellular glycocalyx in NP uptake is still uncovered. Here, we in situ monitored the cellular uptake of gold NPs─functionalized with positively charged alkaline thiol (TMA)─into adhered cancer cells with or without preliminary glycocalyx digestion. Proteoglycan (PG) components of the glycocalyx were treated by the chondroitinase ABC enzyme. It acts on chondroitin 4-sulfate, chondroitin 6-sulfate, and dermatan sulfate and slowly on hyaluronate. The uptake measurements of HeLa cells were performed by applying a high-throughput label-free optical biosensor based on resonant waveguide gratings. The positively charged gold NPs were used with different sizes [d = 2.6, 4.2, and 7.0 nm, small (S), medium (M), and large(L), respectively]. Negatively charged citrate-capped tannic acid (CTA, d = 5.5 nm) NPs were also used in control experiments. Real-time biosensor data confirmed the cellular uptake of the functionalized NPs, which was visually proved by transmission electron microscopy. It was found that the enzymatic digestion facilitated the entry of the positively charged S- and M-sized NPs, being more pronounced for the M-sized. Other enzymes digesting different components of the glycocalyx were also employed, and the results were compared. Glycosaminoglycan digesting heparinase III treatment also increased, while glycoprotein and glycolipid modifying neuraminidase decreased the NP uptake by HeLa cells. This suggests that the sialic acid residues increase, while heparan sulfate decreases the uptake of positively charged NPs. Our results raise the hypothesis that cellular uptake of 2-4 nm positively charged NPs is facilitated by glycoprotein and glycolipid components of the glycocalyx but inhibited by PGs.
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Affiliation(s)
- Beatrix Peter
- Nanobiosensorics
Laboratory, Institute of Technical Physics
and Materials Science, Centre for Energy Research, Konkoly-Thege út 29-33, BudapestH-1120, Hungary,
| | - Nicolett Kanyo
- Nanobiosensorics
Laboratory, Institute of Technical Physics
and Materials Science, Centre for Energy Research, Konkoly-Thege út 29-33, BudapestH-1120, Hungary
| | - Kinga Dora Kovacs
- Nanobiosensorics
Laboratory, Institute of Technical Physics
and Materials Science, Centre for Energy Research, Konkoly-Thege út 29-33, BudapestH-1120, Hungary,Department
of Biological Physics, Eötvös
University, BudapestH 1117, Hungary
| | - Viktor Kovács
- Nanobiosensorics
Laboratory, Institute of Technical Physics
and Materials Science, Centre for Energy Research, Konkoly-Thege út 29-33, BudapestH-1120, Hungary
| | - Inna Szekacs
- Nanobiosensorics
Laboratory, Institute of Technical Physics
and Materials Science, Centre for Energy Research, Konkoly-Thege út 29-33, BudapestH-1120, Hungary
| | - Béla Pécz
- Thin
Films Laboratory, Institute of Technical
Physics and Materials Science, Centre for Energy Research, Konkoly-Thege út 29-33, BudapestH-1120, Hungary
| | - Kinga Molnár
- Department
of Anatomy, Cell and Developmental Biology, ELTE, Eötvös Loránd University, Pázmány Péter Stny. 1/C, BudapestH-1117, Hungary
| | - Hideyuki Nakanishi
- Department
of Macromolecular Science and Engineering, Graduate School of Science
and Technology, Kyoto Institute of Technology, Matsugasaki, Kyoto606-8585, Japan
| | - Istvan Lagzi
- Department
of Physics, Institute of Physics, Budapest
University of Technology and Economics, Műegyetem Rkp. 3, BudapestH-1111, Hungary,ELKH-BME
Condensed Matter Research Group, Műegyetem Rkp. 3, BudapestH-1111, Hungary
| | - Robert Horvath
- Nanobiosensorics
Laboratory, Institute of Technical Physics
and Materials Science, Centre for Energy Research, Konkoly-Thege út 29-33, BudapestH-1120, Hungary
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Kocsis M, Szabados M, Ötvös SB, Samu GF, Fogarassy Z, Pécz B, Kukovecz Á, Kónya Z, Sipos P, Pálinkó I, Varga G. Selective production of imines and benzimidazoles by cooperative bismuth(III)/transition metal ion catalysis. J Catal 2022. [DOI: 10.1016/j.jcat.2022.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Lo Nigro R, Fiorenza P, Pécz B, Eriksson J. Nanotechnology for Electronic Materials and Devices. Nanomaterials (Basel) 2022; 12:3319. [PMID: 36234447 PMCID: PMC9565597 DOI: 10.3390/nano12193319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
The historical scaling down of electronics devices is no longer the main goal of the International Roadmap for Devices and Systems [...].
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Affiliation(s)
- Raffaella Lo Nigro
- Consiglio Nazionale della Ricerche (CNR), Istituto per la Microelettronica e Microsistemi (IMM), Strada VIII, 5, 95121 Catania, Italy
| | - Patrick Fiorenza
- Consiglio Nazionale della Ricerche (CNR), Istituto per la Microelettronica e Microsistemi (IMM), Strada VIII, 5, 95121 Catania, Italy
| | - Béla Pécz
- Centre for Energy Research, Institute for Technical Physics and Materials Science Research, Konkoly-Thege, 29-33, 1121 Budapest, Hungary
| | - Jens Eriksson
- Department of Physics, Chemistry and Biology (IFM), University of Linkoping, Campus Valla, Fysikhuset, SE-581 83 Linkoping, Sweden
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Szamosvölgyi Á, Rajkumar T, Sápi A, Szenti I, Ábel M, Gómez-Pérez JF, Baán K, Fogarassy Z, Dodony E, Pécz B, Garg S, Kiss J, Kukovecz Á, Kónya Z. Interfacial Ni active sites strike solid solutional counterpart in CO2 hydrogenation. Environmental Technology & Innovation 2022. [DOI: 10.1016/j.eti.2022.102747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Panasci SE, Koos A, Schilirò E, Di Franco S, Greco G, Fiorenza P, Roccaforte F, Agnello S, Cannas M, Gelardi FM, Sulyok A, Nemeth M, Pécz B, Giannazzo F. Multiscale Investigation of the Structural, Electrical and Photoluminescence Properties of MoS 2 Obtained by MoO 3 Sulfurization. Nanomaterials (Basel) 2022; 12:182. [PMID: 35055201 PMCID: PMC8778062 DOI: 10.3390/nano12020182] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/01/2022] [Accepted: 01/03/2022] [Indexed: 01/27/2023]
Abstract
In this paper, we report a multiscale investigation of the compositional, morphological, structural, electrical, and optical emission properties of 2H-MoS2 obtained by sulfurization at 800 °C of very thin MoO3 films (with thickness ranging from ~2.8 nm to ~4.2 nm) on a SiO2/Si substrate. XPS analyses confirmed that the sulfurization was very effective in the reduction of the oxide to MoS2, with only a small percentage of residual MoO3 present in the final film. High-resolution TEM/STEM analyses revealed the formation of few (i.e., 2-3 layers) of MoS2 nearly aligned with the SiO2 surface in the case of the thinnest (~2.8 nm) MoO3 film, whereas multilayers of MoS2 partially standing up with respect to the substrate were observed for the ~4.2 nm one. Such different configurations indicate the prevalence of different mechanisms (i.e., vapour-solid surface reaction or S diffusion within the film) as a function of the thickness. The uniform thickness distribution of the few-layer and multilayer MoS2 was confirmed by Raman mapping. Furthermore, the correlative plot of the characteristic A1g-E2g Raman modes revealed a compressive strain (ε ≈ -0.78 ± 0.18%) and the coexistence of n- and p-type doped areas in the few-layer MoS2 on SiO2, where the p-type doping is probably due to the presence of residual MoO3. Nanoscale resolution current mapping by C-AFM showed local inhomogeneities in the conductivity of the few-layer MoS2, which are well correlated to the lateral changes in the strain detected by Raman. Finally, characteristic spectroscopic signatures of the defects/disorder in MoS2 films produced by sulfurization were identified by a comparative analysis of Raman and photoluminescence (PL) spectra with CVD grown MoS2 flakes.
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Affiliation(s)
- Salvatore E. Panasci
- Consiglio Nazionale delle Ricerche—Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII 5, 95121 Catania, Italy; (S.E.P.); (E.S.); (S.D.F.); (G.G.); (P.F.); (F.R.); (S.A.)
- Department of Physics and Astronomy, University of Catania, 95123 Catania, Italy
| | - Antal Koos
- Centre for Energy Research, Institute of Technical Physics and Materials Science, Konkoly-Thege ut 29-33, 1121 Budapest, Hungary; (A.K.); (A.S.); (M.N.)
| | - Emanuela Schilirò
- Consiglio Nazionale delle Ricerche—Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII 5, 95121 Catania, Italy; (S.E.P.); (E.S.); (S.D.F.); (G.G.); (P.F.); (F.R.); (S.A.)
| | - Salvatore Di Franco
- Consiglio Nazionale delle Ricerche—Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII 5, 95121 Catania, Italy; (S.E.P.); (E.S.); (S.D.F.); (G.G.); (P.F.); (F.R.); (S.A.)
| | - Giuseppe Greco
- Consiglio Nazionale delle Ricerche—Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII 5, 95121 Catania, Italy; (S.E.P.); (E.S.); (S.D.F.); (G.G.); (P.F.); (F.R.); (S.A.)
| | - Patrick Fiorenza
- Consiglio Nazionale delle Ricerche—Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII 5, 95121 Catania, Italy; (S.E.P.); (E.S.); (S.D.F.); (G.G.); (P.F.); (F.R.); (S.A.)
| | - Fabrizio Roccaforte
- Consiglio Nazionale delle Ricerche—Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII 5, 95121 Catania, Italy; (S.E.P.); (E.S.); (S.D.F.); (G.G.); (P.F.); (F.R.); (S.A.)
| | - Simonpietro Agnello
- Consiglio Nazionale delle Ricerche—Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII 5, 95121 Catania, Italy; (S.E.P.); (E.S.); (S.D.F.); (G.G.); (P.F.); (F.R.); (S.A.)
- Department of Physics and Chemistry Emilio Segrè, University of Palermo, 90123 Palermo, Italy; (M.C.); (F.M.G.)
- ATEN Center, University of Palermo, 90123 Palermo, Italy
| | - Marco Cannas
- Department of Physics and Chemistry Emilio Segrè, University of Palermo, 90123 Palermo, Italy; (M.C.); (F.M.G.)
| | - Franco M. Gelardi
- Department of Physics and Chemistry Emilio Segrè, University of Palermo, 90123 Palermo, Italy; (M.C.); (F.M.G.)
| | - Attila Sulyok
- Centre for Energy Research, Institute of Technical Physics and Materials Science, Konkoly-Thege ut 29-33, 1121 Budapest, Hungary; (A.K.); (A.S.); (M.N.)
| | - Miklos Nemeth
- Centre for Energy Research, Institute of Technical Physics and Materials Science, Konkoly-Thege ut 29-33, 1121 Budapest, Hungary; (A.K.); (A.S.); (M.N.)
| | - Béla Pécz
- Centre for Energy Research, Institute of Technical Physics and Materials Science, Konkoly-Thege ut 29-33, 1121 Budapest, Hungary; (A.K.); (A.S.); (M.N.)
| | - Filippo Giannazzo
- Consiglio Nazionale delle Ricerche—Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII 5, 95121 Catania, Italy; (S.E.P.); (E.S.); (S.D.F.); (G.G.); (P.F.); (F.R.); (S.A.)
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Schilirò E, Giannazzo F, Di Franco S, Greco G, Fiorenza P, Roccaforte F, Prystawko P, Kruszewski P, Leszczynski M, Cora I, Pécz B, Fogarassy Z, Lo Nigro R. Highly Homogeneous Current Transport in Ultra-Thin Aluminum Nitride (AlN) Epitaxial Films on Gallium Nitride (GaN) Deposited by Plasma Enhanced Atomic Layer Deposition. Nanomaterials (Basel) 2021; 11:3316. [PMID: 34947665 PMCID: PMC8709117 DOI: 10.3390/nano11123316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 11/19/2021] [Accepted: 12/03/2021] [Indexed: 11/25/2022]
Abstract
This paper reports an investigation of the structural, chemical and electrical properties of ultra-thin (5 nm) aluminum nitride (AlN) films grown by plasma enhanced atomic layer deposition (PE-ALD) on gallium nitride (GaN). A uniform and conformal coverage of the GaN substrate was demonstrated by morphological analyses of as-deposited AlN films. Transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) analyses showed a sharp epitaxial interface with GaN for the first AlN atomic layers, while a deviation from the perfect wurtzite stacking and oxygen contamination were detected in the upper part of the film. This epitaxial interface resulted in the formation of a two-dimensional electron gas (2DEG) with a sheet charge density ns ≈ 1.45 × 1012 cm-2, revealed by Hg-probe capacitance-voltage (C-V) analyses. Nanoscale resolution current mapping and current-voltage (I-V) measurements by conductive atomic force microscopy (C-AFM) showed a highly homogeneous current transport through the 5 nm AlN barrier, while a uniform flat-band voltage (VFB ≈ 0.3 V) for the AlN/GaN heterostructure was demonstrated by scanning capacitance microscopy (SCM). Electron transport through the AlN film was shown to follow the Fowler-Nordheim (FN) tunneling mechanism with an average barrier height of <ΦB> = 2.08 eV, in good agreement with the expected AlN/GaN conduction band offset.
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Affiliation(s)
- Emanuela Schilirò
- CNR-IMM, Strada VIII, 5, 95121 Catania, Italy; (E.S.); (S.D.F.); (G.G.); (P.F.); (F.R.)
| | - Filippo Giannazzo
- CNR-IMM, Strada VIII, 5, 95121 Catania, Italy; (E.S.); (S.D.F.); (G.G.); (P.F.); (F.R.)
| | - Salvatore Di Franco
- CNR-IMM, Strada VIII, 5, 95121 Catania, Italy; (E.S.); (S.D.F.); (G.G.); (P.F.); (F.R.)
| | - Giuseppe Greco
- CNR-IMM, Strada VIII, 5, 95121 Catania, Italy; (E.S.); (S.D.F.); (G.G.); (P.F.); (F.R.)
| | - Patrick Fiorenza
- CNR-IMM, Strada VIII, 5, 95121 Catania, Italy; (E.S.); (S.D.F.); (G.G.); (P.F.); (F.R.)
| | - Fabrizio Roccaforte
- CNR-IMM, Strada VIII, 5, 95121 Catania, Italy; (E.S.); (S.D.F.); (G.G.); (P.F.); (F.R.)
| | - Paweł Prystawko
- Top-GaN Ltd., Sokolowska 29/37, 01-142 Warsaw, Poland; (P.P.); (P.K.); (M.L.)
- Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, 01-142 Warsaw, Poland
| | - Piotr Kruszewski
- Top-GaN Ltd., Sokolowska 29/37, 01-142 Warsaw, Poland; (P.P.); (P.K.); (M.L.)
- Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, 01-142 Warsaw, Poland
| | - Mike Leszczynski
- Top-GaN Ltd., Sokolowska 29/37, 01-142 Warsaw, Poland; (P.P.); (P.K.); (M.L.)
- Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, 01-142 Warsaw, Poland
| | - Ildiko Cora
- Centre for Energy Research, Institute for Technical Physics and Materials Science Research, Konkoly-Thege, 29-33, 1121 Budapest, Hungary; (I.C.); (B.P.); (Z.F.)
| | - Béla Pécz
- Centre for Energy Research, Institute for Technical Physics and Materials Science Research, Konkoly-Thege, 29-33, 1121 Budapest, Hungary; (I.C.); (B.P.); (Z.F.)
| | - Zsolt Fogarassy
- Centre for Energy Research, Institute for Technical Physics and Materials Science Research, Konkoly-Thege, 29-33, 1121 Budapest, Hungary; (I.C.); (B.P.); (Z.F.)
| | - Raffaella Lo Nigro
- CNR-IMM, Strada VIII, 5, 95121 Catania, Italy; (E.S.); (S.D.F.); (G.G.); (P.F.); (F.R.)
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10
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Kocsis M, Ötvös SB, Samu GF, Fogarassy Z, Pécz B, Kukovecz Á, Kónya Z, Sipos P, Pálinkó I, Varga G. Copper-Loaded Layered Bismuth Subcarbonate-Efficient Multifunctional Heterogeneous Catalyst for Concerted C-S/C-N Heterocyclization. ACS Appl Mater Interfaces 2021; 13:42650-42661. [PMID: 34477369 PMCID: PMC8447192 DOI: 10.1021/acsami.1c09234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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An efficient self-supported
Cu(II)Bi(III) bimetallic catalyst with
a layered structure was designed and developed. By careful characterization
of the as-prepared material, the host structure was identified to
exhibit a Sillen-type bismutite framework, with copper(II) ions being
loaded as guests. The heterogeneous catalyst enabled C–N and
C–S arylations under mild reaction conditions and with high
chemoselectivities, thus furnishing valuable phenothiazines via heterocyclization with wide substrate tolerance. As
corroborated by detailed catalytic studies, the cooperative, bifunctional
catalyst, bearing Lewis acid sites along with copper(II) catalytic
sites, facilitated an intriguing concerted C–N/C–S heterocyclization
mechanism. The heterogeneous nature of the catalytic reactions was
verified experimentally. Importantly, the catalyst was successfully
recycled and reused multiple times, persevering its original structural
order as well as its initial activity.
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Affiliation(s)
- Marianna Kocsis
- Department of Organic Chemistry, University of Szeged, Dóm tér 8, Szeged H-6720, Hungary.,Materials and Solution Structure Research Group, and Interdisciplinary Excellence Centre, Institute of Chemistry, University of Szeged, Aradi Vértanúk tere 1, Szeged H-6720, Hungary
| | - Sándor B Ötvös
- Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstrasse 28, Graz A-8010, Austria
| | - Gergely F Samu
- Department of Physical Chemistry and Materials Science, Interdisciplinary Excellence Centre, University of Szeged, Szeged H-6720, Hungary
| | - Zsolt Fogarassy
- Centre for Energy Research, Institute of Technical Physics and Materials Science, Konkoly, Thege M. út 29-33., Budapest 1121, Hungary
| | - Béla Pécz
- Centre for Energy Research, Institute of Technical Physics and Materials Science, Konkoly, Thege M. út 29-33., Budapest 1121, Hungary
| | - Ákos Kukovecz
- Department of Applied and Environmental Chemistry, University of Szeged, Rerrich Béla tér 1, Szeged H-6720, Hungary
| | - Zoltán Kónya
- Department of Applied and Environmental Chemistry, University of Szeged, Rerrich Béla tér 1, Szeged H-6720, Hungary.,MTA-SZTE Reaction Kinetics and Surface Chemistry Research Group, Rerrich Béla tér 1, Szeged H-6720, Hungary
| | - Pál Sipos
- Materials and Solution Structure Research Group, and Interdisciplinary Excellence Centre, Institute of Chemistry, University of Szeged, Aradi Vértanúk tere 1, Szeged H-6720, Hungary.,Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, Szeged H-6720, Hungary
| | - István Pálinkó
- Department of Organic Chemistry, University of Szeged, Dóm tér 8, Szeged H-6720, Hungary.,Materials and Solution Structure Research Group, and Interdisciplinary Excellence Centre, Institute of Chemistry, University of Szeged, Aradi Vértanúk tere 1, Szeged H-6720, Hungary
| | - Gábor Varga
- Materials and Solution Structure Research Group, and Interdisciplinary Excellence Centre, Institute of Chemistry, University of Szeged, Aradi Vértanúk tere 1, Szeged H-6720, Hungary.,Department of Physical Chemistry and Materials Science, University of Szeged, Rerrich Béla tér 1, Szeged H-6720, Hungary
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11
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Bali K, Bak M, Szarka K, Juhász G, Sáfrán G, Pécz B, Mihály J, Mészáros R. Controlling the morphology of poly(ethyleneimine)/gold nanoassemblies through the variation of pH and electrolyte additives. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.114559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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12
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Kakanakova-Georgieva A, Ivanov IG, Suwannaharn N, Hsu CW, Cora I, Pécz B, Giannazzo F, Sangiovanni DG, Gueorguiev GK. MOCVD of AlN on epitaxial graphene at extreme temperatures. CrystEngComm 2021. [DOI: 10.1039/d0ce01426e] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Appearance of luminescent centers with narrow spectral emission at room temperature in nanometer thin AlN is reported.
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Affiliation(s)
| | - Ivan G. Ivanov
- Department of Physics
- Chemistry and Biology (IFM)
- Linköping University
- 581 83 Linköping
- Sweden
| | - Nattamon Suwannaharn
- Department of Physics
- Chemistry and Biology (IFM)
- Linköping University
- 581 83 Linköping
- Sweden
| | - Chih-Wei Hsu
- Department of Physics
- Chemistry and Biology (IFM)
- Linköping University
- 581 83 Linköping
- Sweden
| | - Ildikó Cora
- Centre for Energy Research
- Institute of Technical Physics and Materials Science
- Budapest
- Hungary
| | - Béla Pécz
- Centre for Energy Research
- Institute of Technical Physics and Materials Science
- Budapest
- Hungary
| | - Filippo Giannazzo
- Consiglio Nazionale delle Ricerche
- Istituto per la Microelettronica e Microsistemi
- Catania
- Italy
| | - Davide G. Sangiovanni
- Department of Physics
- Chemistry and Biology (IFM)
- Linköping University
- 581 83 Linköping
- Sweden
| | - Gueorgui K. Gueorguiev
- Department of Physics
- Chemistry and Biology (IFM)
- Linköping University
- 581 83 Linköping
- Sweden
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13
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Pécz B, Nicotra G, Giannazzo F, Yakimova R, Koos A, Kakanakova-Georgieva A. Indium Nitride at the 2D Limit. Adv Mater 2021; 33:e2006660. [PMID: 33225494 DOI: 10.1002/adma.202006660] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/01/2020] [Indexed: 06/11/2023]
Abstract
The properties of 2D InN are predicted to substantially differ from the bulk crystal. The predicted appealing properties relate to strong in- and out-of-plane excitons, high electron mobility, efficient strain engineering of their electronic and optical properties, and strong application potential in gas sensing. Until now, the realization of 2D InN remained elusive. In this work, the formation of 2D InN and measurements of its bandgap are reported. Bilayer InN is formed between graphene and SiC by an intercalation process in metal-organic chemical vapor deposition (MOCVD). The thickness uniformity of the intercalated structure is investigated by conductive atomic force microscopy (C-AFM) and the structural properties by atomic resolution transmission electron microscopy (TEM). The coverage of the SiC surface is very high, above 90%, and a major part of the intercalated structure is represented by two sub-layers of indium (In) bonded to nitrogen (N). Scanning tunneling spectroscopy (STS) measurements give a bandgap value of 2 ± 0.1 eV for the 2D InN. The stabilization of 2D InN with a pragmatic wide bandgap and high lateral uniformity of intercalation is demonstrated.
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Affiliation(s)
- Béla Pécz
- Centre for Energy Research, Institute for Technical Physics and Materials Science, Konkoly-Thege M. út 29-33, Budapest, 1121, Hungary
| | - Giuseppe Nicotra
- Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi, Strada VIII, n. 5, Zona Industriale, Catania, I-95121, Italy
| | - Filippo Giannazzo
- Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi, Strada VIII, n. 5, Zona Industriale, Catania, I-95121, Italy
| | - Rositsa Yakimova
- Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping, 581 83, Sweden
| | - Antal Koos
- Centre for Energy Research, Institute for Technical Physics and Materials Science, Konkoly-Thege M. út 29-33, Budapest, 1121, Hungary
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14
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Kakanakova-Georgieva A, Gueorguiev GK, Sangiovanni DG, Suwannaharn N, Ivanov IG, Cora I, Pécz B, Nicotra G, Giannazzo F. Nanoscale phenomena ruling deposition and intercalation of AlN at the graphene/SiC interface. Nanoscale 2020; 12:19470-19476. [PMID: 32960193 DOI: 10.1039/d0nr04464d] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The possibility for kinetic stabilization of prospective 2D AlN was explored by rationalizing metal organic chemical vapor deposition (MOCVD) processes of AlN on epitaxial graphene. From the wide range of temperatures which can be covered in the same MOCVD reactor, the deposition was performed at the selected temperatures of 700, 900, and 1240 °C. The characterization of the structures by atomic force microscopy, electron microscopy and Raman spectroscopy revealed a broad range of surface nucleation and intercalation phenomena. These phenomena included the abundant formation of nucleation sites on graphene, the fragmentation of the graphene layers which accelerated with the deposition temperature, the delivery of excess precursor-derived carbon adatoms to the surface, as well as intercalation of sub-layers of aluminum atoms at the graphene/SiC interface. The conceptual understanding of these nanoscale phenomena was supported by our previous comprehensive ab initio molecular dynamics (AIMD) simulations of the surface reaction of trimethylaluminum, (CH3)3Al, precursor with graphene. A case of applying trimethylindium, (CH3)3In, precursor to epitaxial graphene was considered in a comparative way.
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15
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Varga G, Sápi A, Varga T, Baán K, Szenti I, Halasi G, Mucsi R, Óvári L, Kiss J, Fogarassy Z, Pécz B, Kukovecz Á, Kónya Z. Ambient pressure CO2 hydrogenation over a cobalt/manganese-oxide nanostructured interface: A combined in situ and ex situ study. J Catal 2020. [DOI: 10.1016/j.jcat.2020.03.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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16
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Németh P, McColl K, Smith RL, Murri M, Garvie LAJ, Alvaro M, Pécz B, Jones AP, Corà F, Salzmann CG, McMillan PF. Diamond-Graphene Composite Nanostructures. Nano Lett 2020; 20:3611-3619. [PMID: 32267704 PMCID: PMC7227005 DOI: 10.1021/acs.nanolett.0c00556] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 03/20/2020] [Indexed: 06/11/2023]
Abstract
The search for new nanostructural topologies composed of elemental carbon is driven by technological opportunities as well as the need to understand the structure and evolution of carbon materials formed by planetary shock impact events and in laboratory syntheses. We describe two new families of diamond-graphene (diaphite) phases constructed from layered and bonded sp3 and sp2 nanostructural units and provide a framework for classifying the members of this new class of materials. The nanocomposite structures are identified within both natural impact diamonds and laboratory-shocked samples and possess diffraction features that have previously been assigned to lonsdaleite and postgraphite phases. The diaphite nanocomposites represent a new class of high-performance carbon materials that are predicted to combine the superhard qualities of diamond with high fracture toughness and ductility enabled by the graphitic units and the atomically defined interfaces between the sp3- and sp2-bonded nanodomains.
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Affiliation(s)
- Péter Németh
- Institute
of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117 Budapest, Hungary
- Department
of Earth and Environmental Sciences, University
of Pannonia, Egyetem
út 10, 8200 Veszprém, Hungary
| | - Kit McColl
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Rachael L. Smith
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Mara Murri
- Department
of Earth and Environmental Sciences, University
of Pavia, Via A. Ferrata 1, 27100 Pavia, Italy
- Department
of Earth and Environmental Sciences, University
of Milano-Bicocca, Piazza
della Scienza 4, I-20126 Milano, Italy
| | - Laurence A. J. Garvie
- Center for
Meteorite Studies, Arizona State University, Tempe, Arizona 85287-6004, United States
| | - Matteo Alvaro
- Department
of Earth and Environmental Sciences, University
of Pavia, Via A. Ferrata 1, 27100 Pavia, Italy
| | - Béla Pécz
- Institute
of Technical Physics and Materials Science, Centre for Energy Research, Konkoly-Thege út 29-33, 1121 Budapest, Hungary
| | - Adrian P. Jones
- Department
of Earth Sciences, University College London, WC1E 6BT London, United Kingdom
| | - Furio Corà
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Christoph G. Salzmann
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Paul F. McMillan
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
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17
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Bali K, Dúzs B, Sáfrán G, Pécz B, Mészáros R. Effect of Added Surfactant on Poly(Ethylenimine)-Assisted Gold Nanoparticle Formation. Langmuir 2019; 35:14007-14016. [PMID: 31589455 DOI: 10.1021/acs.langmuir.9b03055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In a variety of applications, functionalization of gold nanoparticles is needed to ensure adequate surface charge and hydrophobicity for their biodistribution, interparticle interactions, or self-organization. In the present paper, we provide an economic way for the synthesis of hydrophobized poly(ethylenimine) (PEI) capped gold nanoparticles at room temperature using sodium dodecyl sulfate (SDS). The approach is based on the controlled competition between the nucleation of gold nanophases within the PEI molecules and the SDS binding onto their amine groups. This can be achieved via utilizing the strongly irreversible nature of the association between the oppositely charged polymer and that of the surfactant molecules. Specifically, by varying the order and timing of SDS addition during the process of gold nanoassembly formation, the size distribution, the morphology, and the local hydrophobic environment of the produced Au-PEI/SDS nanohybrids can be tuned even at one composition of the system. The results may be further exploited for the preparation of noble metal nanoassemblies with controlled hydrophobicity and charge.
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Affiliation(s)
- Krisztina Bali
- Laboratory of Interfaces and Nanosized Systems, Institute of Chemistry , ELTE Eötvös Loránd University , H-1117 Budapest , Pázmány Péter sétány 1/A , Hungary
| | - Brigitta Dúzs
- Laboratory of Interfaces and Nanosized Systems, Institute of Chemistry , ELTE Eötvös Loránd University , H-1117 Budapest , Pázmány Péter sétány 1/A , Hungary
| | - György Sáfrán
- Institute of Technical Physics and Materials Sciences, Centre for Energy Research, H.A.S. , H-1121 Budapest , Konkoly Thege M. út 29-33 , Hungary
| | - Béla Pécz
- Institute of Technical Physics and Materials Sciences, Centre for Energy Research, H.A.S. , H-1121 Budapest , Konkoly Thege M. út 29-33 , Hungary
| | - Róbert Mészáros
- Laboratory of Interfaces and Nanosized Systems, Institute of Chemistry , ELTE Eötvös Loránd University , H-1117 Budapest , Pázmány Péter sétány 1/A , Hungary
- Department of Chemistry , University J. Selyeho , 945 01 Komárno , Slovakia
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18
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Vouroutzis N, Stoemenos J, Frangis N, Radnóczi GZ, Knez D, Hofer F, Pécz B. Structural characterization of poly-Si Films crystallized by Ni Metal Induced Lateral Crystallization. Sci Rep 2019; 9:2844. [PMID: 30808923 PMCID: PMC6391529 DOI: 10.1038/s41598-019-39503-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 01/28/2019] [Indexed: 11/08/2022] Open
Abstract
The growth of the poly-Si films was studied by Transmission Electron Microscopy (TEM) after Ni Metal Induced Lateral Crystallization (Ni-MILC) of amorphous Si films at 413 °C. Significant differences in the morphology and the mode of growth of the films were observed, in comparison to films grown at temperatures above 500 °C. It was shown that at 413 °C the Solid Phase Crystallization (SPC), which acts in parallel with the Ni-MILC process at temperatures above 500 °C is suppressed. The suppression of SPC results in substantial change in the mode of growth. The poly-Si film grown at 413 °C consists of whiskers, which can be classified into two categories. Those growing fast along the <111> direction, which were already observed in conventional Ni-MILC above 500 °C and whiskers grown along random crystallographic orientations having significantly slower growth rates. Because of the large difference in growth rates of the whiskers, significant orientation filtering due to growth-velocity competition is observed. The uniform poly-Si films consist of a mixture of fast <111> type whiskers and slow ones, grown in other orientations, resulting in a tweed-like structure.
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Affiliation(s)
- N Vouroutzis
- Department of Physics, Aristotle University of Thessaloniki, GR-54124, Thessaloniki, Greece
| | - J Stoemenos
- Department of Physics, Aristotle University of Thessaloniki, GR-54124, Thessaloniki, Greece
| | - N Frangis
- Department of Physics, Aristotle University of Thessaloniki, GR-54124, Thessaloniki, Greece
| | - G Z Radnóczi
- Institute for Technical Physics and Materials Sci., Centre for Energy Research, Hungarian Academy of Sciences, MTA EK MFA, 1121, Budapest, Konkoly-Thege M. u. 29-33, Hungary
| | - D Knez
- Institute for Electron Microscopy and Nanoanalysis & Graz Centre for Electron Microscopy, TU Graz, Steyrergasse 17, 8010, Graz, Austria
| | - F Hofer
- Institute for Electron Microscopy and Nanoanalysis & Graz Centre for Electron Microscopy, TU Graz, Steyrergasse 17, 8010, Graz, Austria
| | - B Pécz
- Institute for Technical Physics and Materials Sci., Centre for Energy Research, Hungarian Academy of Sciences, MTA EK MFA, 1121, Budapest, Konkoly-Thege M. u. 29-33, Hungary.
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19
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Németh G, Datz D, Pekker Á, Saito T, Domanov O, Shiozawa H, Lenk S, Pécz B, Koppa P, Kamarás K. Near-field infrared microscopy of nanometer-sized nickel clusters inside single-walled carbon nanotubes. RSC Adv 2019; 9:34120-34124. [PMID: 35529972 PMCID: PMC9073632 DOI: 10.1039/c9ra07089c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 09/19/2019] [Indexed: 11/21/2022] Open
Abstract
Nickel nanoclusters grown inside single-walled carbon nanotubes (SWCNT) were studied by infrared scattering-type scanning near-field optical microscopy (s-SNOM).
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20
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Bali K, Sáfrán G, Pécz B, Mészáros R. Preparation of Gold Nanocomposites with Tunable Charge and Hydrophobicity via the Application of Polymer/Surfactant Complexation. ACS Omega 2017; 2:8709-8716. [PMID: 31457402 PMCID: PMC6645515 DOI: 10.1021/acsomega.7b01623] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 11/17/2017] [Indexed: 06/10/2023]
Abstract
During the synthesis of gold nanoparticle (NP) assemblies, the interfacial charge and hydrophobicity of the primary particles play a distinguished role. In the present article, we demonstrate that the association of poly(ethyleneimine) (PEI) capped gold NPs with sodium alkyl sulfates provide a powerful route for the manipulation of these interfacial properties. Dynamic light-scattering, electrophoretic mobility, UV-vis-near-infrared spectroscopy, nanoparticle tracking analysis, and transmission electron microscopy measurements were used to characterize the PEI/surfactant/gold nanoassemblies. The results indicate the formation of gold NPs surrounded by a PEI/surfactant shell with composition-dependent charge and hydrophobicity. The mean size and the aggregation of the nanoassemblies can be fine tuned by the amount of surfactant bound to the primary gold NPs as well as by the application of controlled mixing methods. The specific features of the prepared nanocomposites may be further exploited in next-generation applications.
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Affiliation(s)
- Krisztina Bali
- Laboratory
of Interfaces and Nanosized Systems, Institute of Chemistry, Eötvös Loránd University, Pázmány Péter
sétány 1/A, H-1117 Budapest, Hungary
| | - György Sáfrán
- Research
Institute for Technical Physics and Materials Sciences (RITP), Centre
for Energy Research, H.A.S., Konkoly Thege M. út 29-33, H-1121 Budapest, Hungary
| | - Béla Pécz
- Research
Institute for Technical Physics and Materials Sciences (RITP), Centre
for Energy Research, H.A.S., Konkoly Thege M. út 29-33, H-1121 Budapest, Hungary
| | - Róbert Mészáros
- Laboratory
of Interfaces and Nanosized Systems, Institute of Chemistry, Eötvös Loránd University, Pázmány Péter
sétány 1/A, H-1117 Budapest, Hungary
- Department
of Chemistry, University J. Selyeho, 94501 Komárno, Slovakia
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Cora I, Mezzadri F, Boschi F, Bosi M, Čaplovičová M, Calestani G, Dódony I, Pécz B, Fornari R. The real structure of ε-Ga2O3 and its relation to κ-phase. CrystEngComm 2017. [DOI: 10.1039/c7ce00123a] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Leiterer C, Brönstrup G, Jahr N, Talkenberg F, Radnóczi GZ, Pécz B, Christiansen S, Sivakov V. Index matching at the nanoscale: light scattering by core-shell Si/SiO x nanowires. Nanotechnology 2016; 27:435202. [PMID: 27655170 DOI: 10.1088/0957-4484/27/43/435202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Silicon nanowires (SiNWs) show strong resonant wavelength enhancement in terms of absorption as well as scattering of light. However, in most optoelectronic device concepts the SiNWs should be surrounded by a contact layer. Ideally, such a layer can also act as an index matching layer which could nearly halve the strong reflectance of light by silicon. Our results show that this reduction can be overcome at the nanometer scale, i.e. SiNWs embedded in a silica (SiO x ) layer can not only maintain their high scattering cross sections but also their strong polarization dependent scattering. Such effects can be useful for light harvesting or optoelectronic applications. Moreover, we show that it is possible to optically determine the diameters of the embedded nanoscale silicon (Si) cores.
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Vágó A, Szakacs G, Sáfrán G, Horvath R, Pécz B, Lagzi I. One-step green synthesis of gold nanoparticles by mesophilic filamentous fungi. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2015.12.019] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Bosi M, Attolini G, Negri M, Ferrari C, Buffagni E, Frigeri C, Calicchio M, Pécz B, Riesz F, Cora I, Osváth Z, Jiang L, Borionetti G. Defect structure and strain reduction of 3C-SiC/Si layers obtained with the use of a buffer layer and methyltrichlorosilane addition. CrystEngComm 2016. [DOI: 10.1039/c6ce00280c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Kiss ÁK, Rauch EF, Pécz B, Szívós J, Lábár JL. A Tool for Local Thickness Determination and Grain Boundary Characterization by CTEM and HRTEM Techniques. Microsc Microanal 2015; 21:422-435. [PMID: 25801740 DOI: 10.1017/s1431927615000112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A new approach for measurement of local thickness and characterization of grain boundaries is presented. The method is embodied in a software tool that helps to find and set sample orientations useful for high-resolution transmission electron microscopic (HRTEM) examination of grain boundaries in polycrystalline thin films. The novelty is the simultaneous treatment of the two neighboring grains and orienting both grains and the boundary plane simultaneously. The same metric matrix-based formalism is used for all crystal systems. Input into the software tool includes orientation data for the grains in question, which is determined automatically for a large number of grains by the commercial ASTAR program. Grain boundaries suitable for HRTEM examination are automatically identified by our software tool. Individual boundaries are selected manually for detailed HRTEM examination from the automatically identified set. Goniometer settings needed to observe the selected boundary in HRTEM are advised by the software. Operation is demonstrated on examples from cubic and hexagonal crystal systems.
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Affiliation(s)
- Ákos K Kiss
- 1Hungarian Academy of Sciences,Research Center for Natural Sciences,Institute for Technical Physics and Materials Science,Konkoly Thege M. út 29-33,H-1121 Budapest,Hungary
| | - Edgar F Rauch
- 3SIMaP,Grenoble INP/CNRS,1130 rue de la Piscine,BP 75,F-38402 St Martin D'Heres,France
| | - Béla Pécz
- 1Hungarian Academy of Sciences,Research Center for Natural Sciences,Institute for Technical Physics and Materials Science,Konkoly Thege M. út 29-33,H-1121 Budapest,Hungary
| | - János Szívós
- 1Hungarian Academy of Sciences,Research Center for Natural Sciences,Institute for Technical Physics and Materials Science,Konkoly Thege M. út 29-33,H-1121 Budapest,Hungary
| | - János L Lábár
- 1Hungarian Academy of Sciences,Research Center for Natural Sciences,Institute for Technical Physics and Materials Science,Konkoly Thege M. út 29-33,H-1121 Budapest,Hungary
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Frayssinet E, Beaumont B, Faurie JP, Gibart P, Makkai Z, Pécz B, Lefebvre P, Valvin P. Micro Epitaxial lateral overgrowth of GaN/sapphire by Metal Organic Vapour Phase Epitaxy. ACTA ACUST UNITED AC 2014. [DOI: 10.1557/s109257830000034x] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
GaN/sapphire layers have been grown by Metal Organic Vapour Phase Epitaxy (MOVPE). An amorphous silicon nitride layer is deposited using a SiH4/NH3 mixture prior to the growth of the low temperature GaN buffer layer. Such a process induces a 3D nucleation at the early beginning of the growth, resulting in a kind of maskless ELO process with random opening sizes. This produces a significant decrease of the threading dislocation (TD) density compared to the best GaN/sapphire templates. Ultra Low Dislocation density (ULD) GaN layers were obtained with TD density as low as 7×107cm−2 as measured by atomic force microscopy (AFM), cathodoluminescence and transmission electron microscopy (TEM). Time-resolved photoluminescence experiments show that the lifetime of the A free exciton is principally limited by capture onto residual donors, similar to the situation for nearly dislocation-free homoepitaxial layers.
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Ahl JP, Behmenburg H, Giesen C, Regolin I, Prost W, Tegude FJ, Radnoczi GZ, Pécz B, Kalisch H, Jansen RH, Heuken M. Gold catalyst initiated growth of GaN nanowires by MOCVD. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/pssc.201000992] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Watts BE, Bosi M, Attolini G, Battistig G, Dobos L, Pécz B. CBr4 as precursor for VPE growth of cubic silicon carbide. Cryst Res Technol 2010. [DOI: 10.1002/crat.200900590] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Basa P, Molnár G, Dobos L, Pécz B, Tóth L, Tóth AL, Koós AA, Dózsa L, Nemcsics A, Horváth ZJ. Formation of ge nanocrystals in SiO2 by electron beam evaporation. J Nanosci Nanotechnol 2008; 8:818-822. [PMID: 18464412 DOI: 10.1166/jnn.2008.a122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Ge nanocrystals were formed by electron beam evaporation on SiO2 covered Si substrates. The size and distribution of the nanocrystals were studied by atomic force microscopy, scanning electron microscopy and cross-sectional transmission electron microscopy. Dependencies of the nanocrystal size, of the nanocrystal surface coverage, and sheet resistance obtained by van der Pauw method of the Ge layer have been found on the evaporation time. The suggested growth mechanism for the formation of nanocrystals is the Volmer-Weber type. The sheet resistance exhibited a power dependence on the nanocrystal size.
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Affiliation(s)
- P Basa
- Hungarian Academy of Sciences, Research Institute for Technical Physics and Materials Science, Budapest, P.O. Box49, H-1525, Hungary
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Horváth ZJ, Basa P, Jászi T, Pap AE, Dobos L, Pécz B, Tóth L, Szöllosi P, Nagy K. Electrical and memory properties of Si3N4 MIS structures with embedded Si nanocrystals. J Nanosci Nanotechnol 2008; 8:812-817. [PMID: 18464411 DOI: 10.1166/jnn.2008.a120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Memory structures with an embedded sheet of separated Si nanocrystals were prepared by low pressure chemical vapour deposition using a Si3N4 control layer and different Si2O2 or Si3N4 tunnel layers. It was obtained that Si nanocrystals improve the charging behaviour of the MNOS structures. Memory window width of 1.3 V and 2.0 V were obtained for pulse amplitudes of +/-9 V and +/-10 V, 100 ms, respectively. The extrapolated memory window after 10 years is about 15% of its initial value.
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Affiliation(s)
- Z J Horváth
- Hungarian Academy of Sciences, Research Institute for Technical Physics and Materials Science, Budapest 114, P.O. Box 49, H-1525, Hungary
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Abstract
A relatively easy and convenient process for the preparation of transmission electron microscope specimens of buried interfaces is described. The method is based on the alignment and realignment of the specimen rotation centre during ion milling. The ion-milling time interval in which good samples are obtained is substantially extended in this way.
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Affiliation(s)
- G Z Radnóczi
- Research Institute for Technical Physics and Materials Science (MFA) of the Hungarian Academy of Sciences, H-1525 Budapest, P.O. Box 49, Hungary.
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Barna PB, Adamik M, Sáfrán G, Pécz B, Bergauer A, Bangert H. Peculiar lamellar structure in Al single crystals grown in oxygen-doped Al and Al-Sn thin films. ACTA ACUST UNITED AC 1994. [DOI: 10.1002/pssa.2211460127] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abstract
A novel, rapid, and simple method is described for the preparation of InP based samples for investigation by transmission electron microscopy (TEM). The key feature of the technique is Ar+ ion bombardment in an iodine ambient. Cross sectional micrographs of Au/InP samples are shown as an example. The technique developed produces a large area of transparent region.
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Affiliation(s)
- A Barna
- Research Institute for Technical Physics, Hungarian Academy of Sciences, Budapest
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