1
|
Martinez P, Blanchet V, Descamps D, Dory JB, Fourment C, Papagiannouli I, Petit S, Raty JY, Noé P, Gaudin J. Sub-Picosecond Non-Equilibrium States in the Amorphous Phase of GeTe Phase-Change Material Thin Films. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2102721. [PMID: 34427368 DOI: 10.1002/adma.202102721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/01/2021] [Indexed: 06/13/2023]
Abstract
The sub-picosecond response of amorphous germanium telluride thin film to a femtosecond laser excitation is investigated using frequency-domain interferometry and ab initio molecular dynamics. The time-resolved measurement of the surface dynamics reveals a shrinkage of the film with a dielectric properties' response faster than 300 fs. The systematic ab initio molecular dynamics simulations in non-equilibrium conditions allow the atomic configurations to be retrieved for ionic temperature from 300 to 1100 K and width of the electron distribution from 0.001 to 1.0 eV. Local order of the structures is characterized by in-depth analysis of the angle distribution, phonon modes, and pair distribution function, which evidence a transition toward a new amorphous electronic excited state close in bonding/structure to the liquid state. The results shed a new light on the optically highly excited states in chalcogenide materials involved in both important processes: phase-change materials in memory devices and ovonic threshold switching phenomenon induced by a static field.
Collapse
Affiliation(s)
- Paloma Martinez
- CELIA, Université Bordeaux, CEA, CNRS, UMR 5107, 351 Cours de la Libération, Talence, F-33405, France
| | - Valérie Blanchet
- CELIA, Université Bordeaux, CEA, CNRS, UMR 5107, 351 Cours de la Libération, Talence, F-33405, France
| | - Dominique Descamps
- CELIA, Université Bordeaux, CEA, CNRS, UMR 5107, 351 Cours de la Libération, Talence, F-33405, France
| | - Jean-Baptiste Dory
- Université Grenoble Alpes, CEA, LETI, 17 rue des Martyrs, Grenoble Cedex 9, F-38000, France
| | - Claude Fourment
- CELIA, Université Bordeaux, CEA, CNRS, UMR 5107, 351 Cours de la Libération, Talence, F-33405, France
- CEA-CESTA, 15 avenue des Sablières, CS 60001, Le Barp CEDEX, F-33116, France
| | - Irène Papagiannouli
- CELIA, Université Bordeaux, CEA, CNRS, UMR 5107, 351 Cours de la Libération, Talence, F-33405, France
| | - Stéphane Petit
- CELIA, Université Bordeaux, CEA, CNRS, UMR 5107, 351 Cours de la Libération, Talence, F-33405, France
| | - Jean-Yves Raty
- Université Grenoble Alpes, CEA, LETI, 17 rue des Martyrs, Grenoble Cedex 9, F-38000, France
- FRS-FNRS and CESAM, University of Liège, Allée du 6 Août 19, Sart-Tilman, 4000, Belgium
| | - Pierre Noé
- Université Grenoble Alpes, CEA, LETI, 17 rue des Martyrs, Grenoble Cedex 9, F-38000, France
| | - Jérôme Gaudin
- CELIA, Université Bordeaux, CEA, CNRS, UMR 5107, 351 Cours de la Libération, Talence, F-33405, France
| |
Collapse
|
2
|
Cheng Z, Milne T, Salter P, Kim JS, Humphrey S, Booth M, Bhaskaran H. Antimony thin films demonstrate programmable optical nonlinearity. SCIENCE ADVANCES 2021; 7:7/1/eabd7097. [PMID: 33523855 PMCID: PMC7775754 DOI: 10.1126/sciadv.abd7097] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 11/11/2020] [Indexed: 05/31/2023]
Abstract
The use of metals of nanometer dimensions to enhance and manipulate light-matter interactions for emerging plasmonics-enabled nanophotonic and optoelectronic applications is an interesting yet not highly explored area of research beyond plasmonics. Even more importantly, the concept of an active metal that can undergo an optical nonvolatile transition has not been explored. Here, we demonstrate that antimony (Sb), a pure metal, is optically distinguishable between two programmable states as nanoscale thin films. We show that these states, corresponding to the crystalline and amorphous phases of the metal, are stable at room temperature. Crucially from an application standpoint, we demonstrate both its optoelectronic modulation capabilities and switching speed using single subpicosecond pulses. The simplicity of depositing a single metal portends its potential for use in any optoelectronic application where metallic conductors with an actively tunable state are important.
Collapse
Affiliation(s)
- Zengguang Cheng
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, China.
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
| | - Tara Milne
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
| | - Patrick Salter
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK
| | - Judy S Kim
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
- Electron Physical Sciences Imaging Centre, Diamond Light Source Ltd., Didcot OX11 0DE, UK
- Rosalind Franklin Institute, Harwell Campus, Didcot OX11 0FA, UK
| | - Samuel Humphrey
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
| | - Martin Booth
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK
| | - Harish Bhaskaran
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK.
| |
Collapse
|
3
|
Qiu Q, Wu P, Hu Y, Zhai J, Lai T. Mechanism of Nano-Structuring Manipulation of the Crystallization Temperature of Superlattice-like [Ge 8Sb 92/Ge] 3 Phase-Change Films. NANOMATERIALS 2020; 11:nano11010020. [PMID: 33374227 PMCID: PMC7823727 DOI: 10.3390/nano11010020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 12/16/2020] [Accepted: 12/22/2020] [Indexed: 11/16/2022]
Abstract
Superlattice-like (SLL) phase-change film is considered to be a promising phase-change material because it provides more controllabilities for the optimization of multiple performances of phase-change films. However, the mechanism by which SLL structure affects the properties of phase-change films is not well-understood. Here, four SLL phase-change films [Ge8Sb92(15 nm)/Ge (x nm)]3 with different x are fabricated. Their behaviors of crystallization are investigated by measuring sheet resistance and coherent phonon spectroscopy, which show that the crystallization temperature (TC) of these films increases anomalously with x, rather than decreases as the interfacial effects model predicted. A new stress effect is proposed to explain the anomalous increase in TC with x. Raman spectroscopy reveals that Raman shifts of all phonon modes in SLL films deviate from their respective standard Raman shifts in stress-free crystalline films, confirming the presence of stress in SLL films. It is also shown that tensile and compressive stresses exist in Ge and Ge8Sb92 layers, respectively, which agrees with the lattice mismatch between the Ge and Ge8Sb92 constituent layers. It is also found that the stress reduces with increasing x. Such a thickness dependence of stress can be used to explain the increase in crystallization temperature of four SLL films with x according to stress-enhanced crystallization. Our results reveal a new mechanism to affect the crystallization behaviors of SLL phase-change films besides interfacial effect. Stress and interfacial effects actually coexist and compete in SLL films, which can be used to explain the reported anomalous change in crystallization temperature with the film thickness and cycle number of periods in SLL phase-change films.
Collapse
Affiliation(s)
- Qingqian Qiu
- State-Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Sun Yat-Sen University, Guangzhou 510275, China; (Q.Q.); (P.W.)
| | - Pengzhi Wu
- State-Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Sun Yat-Sen University, Guangzhou 510275, China; (Q.Q.); (P.W.)
| | - Yifeng Hu
- Functional Material Research Laboratory, Tongji University, Shanghai 200092, China;
| | - Jiwei Zhai
- Functional Material Research Laboratory, Tongji University, Shanghai 200092, China;
- Correspondence: (J.Z.); (T.L.)
| | - Tianshu Lai
- State-Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Sun Yat-Sen University, Guangzhou 510275, China; (Q.Q.); (P.W.)
- Correspondence: (J.Z.); (T.L.)
| |
Collapse
|
4
|
Sun X, Ehrhardt M, Lotnyk A, Lorenz P, Thelander E, Gerlach JW, Smausz T, Decker U, Rauschenbach B. Crystallization of Ge2Sb2Te5 thin films by nano- and femtosecond single laser pulse irradiation. Sci Rep 2016; 6:28246. [PMID: 27292819 PMCID: PMC4904278 DOI: 10.1038/srep28246] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 06/01/2016] [Indexed: 02/04/2023] Open
Abstract
The amorphous to crystalline phase transformation of Ge2Sb2Te5 (GST) films by UV nanosecond (ns) and femtosecond (fs) single laser pulse irradiation at the same wavelength is compared. Detailed structural information about the phase transformation is collected by x-ray diffraction and high resolution transmission electron microscopy (TEM). The threshold fluences to induce crystallization are determined for both pulse lengths. A large difference between ns and fs pulse irradiation was found regarding the grain size distribution and morphology of the crystallized films. For fs single pulse irradiated GST thin films, columnar grains with a diameter of 20 to 60 nm were obtained as evidenced by cross-sectional TEM analysis. The local atomic arrangement was investigated by high-resolution Cs-corrected scanning TEM. Neither tetrahedral nor off-octahedral positions of Ge-atoms could be observed in the largely defect-free grains. A high optical reflectivity contrast (~25%) between amorphous and completely crystallized GST films was achieved by fs laser irradiation induced at fluences between 13 and 16 mJ/cm2 and by ns laser irradiation induced at fluences between 67 and 130 mJ/cm2. Finally, the fluence dependent increase of the reflectivity is discussed in terms of each photon involved into the crystallization process for ns and fs pulses, respectively.
Collapse
Affiliation(s)
- Xinxing Sun
- Leibniz Institute of Surface Modification, Permoserstr. 15, D-04318 Leipzig, Germany
| | - Martin Ehrhardt
- Leibniz Institute of Surface Modification, Permoserstr. 15, D-04318 Leipzig, Germany
| | - Andriy Lotnyk
- Leibniz Institute of Surface Modification, Permoserstr. 15, D-04318 Leipzig, Germany
| | - Pierre Lorenz
- Leibniz Institute of Surface Modification, Permoserstr. 15, D-04318 Leipzig, Germany
| | - Erik Thelander
- Leibniz Institute of Surface Modification, Permoserstr. 15, D-04318 Leipzig, Germany
| | - Jürgen W Gerlach
- Leibniz Institute of Surface Modification, Permoserstr. 15, D-04318 Leipzig, Germany
| | - Tomi Smausz
- MTA-SZTE Research Group on Photoacoustic Spectroscopy, University of Szeged, Dóm tér 9, H-6720 Szeged, Hungary
| | - Ulrich Decker
- Leibniz Institute of Surface Modification, Permoserstr. 15, D-04318 Leipzig, Germany
| | - Bernd Rauschenbach
- Leibniz Institute of Surface Modification, Permoserstr. 15, D-04318 Leipzig, Germany.,Institute for Experimental Physics II, Leipzig University, Linnéstr. 5, D-04103 Leipzig, Germany
| |
Collapse
|
5
|
Sun Y, Wang X, Du J, Chen N, Yu H, Wu Q, Meng X. Amorphous structure and bonding chemistry of aluminium antimonide(AlSb)) alloy for phase-change memory device. Chem Res Chin Univ 2016. [DOI: 10.1007/s40242-016-5345-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
6
|
Waldecker L, Miller TA, Rudé M, Bertoni R, Osmond J, Pruneri V, Simpson RE, Ernstorfer R, Wall S. Time-domain separation of optical properties from structural transitions in resonantly bonded materials. NATURE MATERIALS 2015. [PMID: 26213898 DOI: 10.1038/nmat4359] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The extreme electro-optical contrast between crystalline and amorphous states in phase-change materials is routinely exploited in optical data storage and future applications include universal memories, flexible displays, reconfigurable optical circuits, and logic devices. Optical contrast is believed to arise owing to a change in crystallinity. Here we show that the connection between optical properties and structure can be broken. Using a combination of single-shot femtosecond electron diffraction and optical spectroscopy, we simultaneously follow the lattice dynamics and dielectric function in the phase-change material Ge2Sb2Te5 during an irreversible state transformation. The dielectric function changes by 30% within 100 fs owing to a rapid depletion of electrons from resonantly bonded states. This occurs without perturbing the crystallinity of the lattice, which heats with a 2-ps time constant. The optical changes are an order of magnitude larger than those achievable with silicon and present new routes to manipulate light on an ultrafast timescale without structural changes.
Collapse
Affiliation(s)
- Lutz Waldecker
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Timothy A Miller
- ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, 08860, Castelldefels, Barcelona, Spain
| | - Miquel Rudé
- ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, 08860, Castelldefels, Barcelona, Spain
| | - Roman Bertoni
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Johann Osmond
- ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, 08860, Castelldefels, Barcelona, Spain
| | - Valerio Pruneri
- ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, 08860, Castelldefels, Barcelona, Spain
- ICREA-Institució Catalana de Recerca i Estudi Avançats, 08015 Barcelona, Spain
| | - Robert E Simpson
- SUTD- Singapore University of Technology &Design, 8 Somapah Road 487372 Singapore, Singapore
| | - Ralph Ernstorfer
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Simon Wall
- ICFO-Institut de Ciències Fotòniques, Mediterranean Technology Park, 08860, Castelldefels, Barcelona, Spain
| |
Collapse
|
7
|
Guo Y, Sun D, Ouyang B, Raja A, Song J, Heinz TF, Brus LE. Probing the Dynamics of the Metallic-to-Semiconducting Structural Phase Transformation in MoS2 Crystals. NANO LETTERS 2015; 15:5081-5088. [PMID: 26134736 DOI: 10.1021/acs.nanolett.5b01196] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We have investigated the phase transformation of bulk MoS2 crystals from the metastable metallic 1T/1T' phase to the thermodynamically stable semiconducting 2H phase. The metastable 1T/1T' material was prepared by Li intercalation and deintercalation. The thermally driven kinetics of the phase transformation were studied with in situ Raman and optical reflection spectroscopies and yield an activation energy of 400 ± 60 meV (38 ± 6 kJ/mol). We calculate the expected minimum energy pathways for these transformations using DFT methods. The experimental activation energy corresponds approximately to the theoretical barrier for a single formula unit, suggesting that nucleation of the phase transformation is quite local. We also report that femtosecond laser writing converts 1T/1T' to 2H in a single laser pass. The mechanisms for the phase transformation are discussed.
Collapse
Affiliation(s)
- Yinsheng Guo
- †Department of Chemistry and ‡Department of Physics, Columbia University, New York, New York 10027, United States
| | | | - Bin Ouyang
- §Mining and Materials Engineering, McGill University, Montreal, QC H3A 0C5, Canada
| | - Archana Raja
- †Department of Chemistry and ‡Department of Physics, Columbia University, New York, New York 10027, United States
| | - Jun Song
- §Mining and Materials Engineering, McGill University, Montreal, QC H3A 0C5, Canada
| | | | - Louis E Brus
- †Department of Chemistry and ‡Department of Physics, Columbia University, New York, New York 10027, United States
| |
Collapse
|
8
|
Mazurenko DA, Nugroho AA, Palstra TTM, van Loosdrecht PHM. Dynamics of spin and orbital phase transitions in YVO3. PHYSICAL REVIEW LETTERS 2008; 101:245702. [PMID: 19113633 DOI: 10.1103/physrevlett.101.245702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Revised: 10/15/2008] [Indexed: 05/27/2023]
Abstract
YVO3 exhibits a well separated sequence of orbital and spin order transitions at 200 and 116 K, followed by a combined spin-orbital reorientation at 77 K. It is shown that the spin order can be destroyed by a sufficiently strong optical pulse within less than 4 ps. In contrast, the orbital reordering transition from C-type to G-type orbital order is slower than 100 ps and goes via an intermediate nonthermal phase. We propose that the dynamics of phase transitions is subjected to symmetry relations between the associated phases.
Collapse
Affiliation(s)
- Dmitry A Mazurenko
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| | | | | | | |
Collapse
|
9
|
|
10
|
Ling Y, Lu F. Measurements of femtosecond pulse temporal profile by means of a Michelson interferometer with a Schottky junction. APPLIED OPTICS 2006; 45:9087-91. [PMID: 17151747 DOI: 10.1364/ao.45.009087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We introduce a new method for femtosecond pulse shape measurement. The interference of two pulses is employed rather than the second-harmonic generation (SHG). Usually, the measurements of the femtosecond pulse is realized by an interferometer in combination with a nonlinear optical material, while the measurement that we describe is realized by means of a Michelson interferometer with a Schottky junction. Only a metal-semiconductor junction (Schottky junction) is needed, and neither the nonlinear optical material nor a photodetector is included. The two-photon absorption arises when the light is strong enough, while there is only a one-photon absorption when the light is weak. And the calculations are in good agreement with the experimental results. In principle, the new technique could be used for the measuring of pulses with any duration and with very low power. Unlike the SHG scheme, in the new method the quality of optics, mechanics, and other elements of the scheme are not essential, and the measurement is easily realized, but the results are quite precise and very sensitive to the light.
Collapse
Affiliation(s)
- Yan Ling
- Department of Physics and the Surface Physics Laboratory, Fudan University, China
| | | |
Collapse
|
11
|
Gómez-Abal R, Ney O, Satitkovitchai K, Hübner W. All-optical subpicosecond magnetic switching in NiO(001). PHYSICAL REVIEW LETTERS 2004; 92:227402. [PMID: 15245259 DOI: 10.1103/physrevlett.92.227402] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2003] [Indexed: 05/24/2023]
Abstract
Combining optical control theory with ab initio quantum chemistry and electronic crystal field theory we explore the laser induced femtosecond spin dynamics. We propose a scenario for ultrafast all-optical magnetic switching that results from the combination of spin-orbit coupling with appropriately shaped short laser pulses. We find that the application of the theory to the multiplet states within the gap of NiO(001) predicts for the first time the possibility of all-optical spin switching within 100 fs. The switching can be observed using any of the multiplets as the intermediate state.
Collapse
Affiliation(s)
- R Gómez-Abal
- Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120, Halle, Germany.
| | | | | | | |
Collapse
|