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Roychowdhury R, Rajput P, Kumar S, Kumar R, Bose A, Jha SN, Sharma TK, Dixit VK. Effect of germanium auto-diffusion on the bond lengths of Ga and P atoms in GaP/Ge(111) investigated by using X-ray absorption spectroscopy. JOURNAL OF SYNCHROTRON RADIATION 2021; 28:480-489. [PMID: 33650560 DOI: 10.1107/s160057752001629x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 12/16/2020] [Indexed: 06/12/2023]
Abstract
The germanium auto-diffusion effects on the inter-atomic distance between the nearest neighbors of the Ga atom in GaP epilayers are investigated using high-resolution X-ray diffraction (HRXRD) and X-ray absorption spectroscopy. The GaP layers grown on Ge (111) are structurally coherent and relaxed but they show the presence of residual strain which is attributed to the auto-diffusion of Ge from the results of secondary ion mass spectrometry and electrochemical capacitance voltage measurements. Subsequently, the inter-atomic distances between the nearest neighbors of Ga atom in GaP are determined from X-ray absorption fine-structure spectra performed at the Ga K-edge. The estimated local bond lengths of Ga with its first and second nearest neighbors show asymmetric variation for the in-plane and out-of-plane direction of GaP/Ge(111). The magnitude and direction of in-plane and out-of-plane microscopic residual strain present in the GaP/Ge are calculated from the difference in bond lengths which explains the presence of macroscopic residual tensile strain estimated from HRXRD. Modified nearest neighbor configurations of Ga in the auto-diffused GaP epilayer are proposed for new possibilities within the GaP/Ge hetero-structure, such as the conversion from indirect to direct band structures and engineering the tensile strain quantum dot structures on (111) surfaces.
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Affiliation(s)
- R Roychowdhury
- Training School Complex, Homi Bhabha National Institute, Anushakti Nagar, Mumbai, India
| | - P Rajput
- Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Shailendra Kumar
- UGC-DAE Consortium for Scientific Research, Indore, Madhya Pradesh, India
| | - R Kumar
- Training School Complex, Homi Bhabha National Institute, Anushakti Nagar, Mumbai, India
| | - A Bose
- Training School Complex, Homi Bhabha National Institute, Anushakti Nagar, Mumbai, India
| | - S N Jha
- Training School Complex, Homi Bhabha National Institute, Anushakti Nagar, Mumbai, India
| | - T K Sharma
- Training School Complex, Homi Bhabha National Institute, Anushakti Nagar, Mumbai, India
| | - V K Dixit
- Training School Complex, Homi Bhabha National Institute, Anushakti Nagar, Mumbai, India
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Self-Diffusion in Perovskite and Perovskite Related Oxides: Insights from Modelling. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10072286] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Perovskite and perovskite related oxides are important materials with applications ranging from solid oxide fuel cells, electronics, batteries and high temperature superconductors. The investigation of physical properties at the atomic scale such as self-diffusion is important to further improve and/or miniaturize electronic or energy related devices. In the present review we examine the oxygen self-diffusion and defect processes in perovskite and perovskite related oxides. This contribution is not meant to be an exhaustive review of the literature but rather aims to highlight the important mechanisms and ways to tune self-diffusion in this important class of energy materials.
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Diffusion and Dopant Activation in Germanium: Insights from Recent Experimental and Theoretical Results. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9122454] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Germanium is an important mainstream material for many nanoelectronic and sensor applications. The understanding of diffusion at an atomic level is important for fundamental and technological reasons. In the present review, we focus on the description of recent studies concerning n-type dopants, isovalent atoms, p-type dopants, and metallic and oxygen diffusion in germanium. Defect engineering strategies considered by the community over the past decade are discussed in view of their potential application to other systems.
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Ion-Beam-Induced Atomic Mixing in Ge, Si, and SiGe, Studied by Means of Isotope Multilayer Structures. MATERIALS 2017; 10:ma10070813. [PMID: 28773172 PMCID: PMC5551856 DOI: 10.3390/ma10070813] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/11/2017] [Accepted: 07/12/2017] [Indexed: 11/30/2022]
Abstract
Crystalline and preamorphized isotope multilayers are utilized to investigate the dependence of ion beam mixing in silicon (Si), germanium (Ge), and silicon germanium (SiGe) on the atomic structure of the sample, temperature, ion flux, and electrical doping by the implanted ions. The magnitude of mixing is determined by secondary ion mass spectrometry. Rutherford backscattering spectrometry in channeling geometry, Raman spectroscopy, and transmission electron microscopy provide information about the structural state after ion irradiation. Different temperature regimes with characteristic mixing properties are identified. A disparity in atomic mixing of Si and Ge becomes evident while SiGe shows an intermediate behavior. Overall, atomic mixing increases with temperature, and it is stronger in the amorphous than in the crystalline state. Ion-beam-induced mixing in Ge shows no dependence on doping by the implanted ions. In contrast, a doping effect is found in Si at higher temperature. Molecular dynamics simulations clearly show that ion beam mixing in Ge is mainly determined by the thermal spike mechanism. In the case of Si thermal spike, mixing prevails at low temperature whereas ion beam-induced enhanced self-diffusion dominates the atomic mixing at high temperature. The latter process is attributed to highly mobile Si di-interstitials formed under irradiation and during damage annealing.
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Toward Defect Engineering Strategies to Optimize Energy and Electronic Materials. APPLIED SCIENCES-BASEL 2017. [DOI: 10.3390/app7070674] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Park JK, Kwon HJ, Lee CE. NMR Observation of Mobile Protons in Proton-Implanted ZnO Nanorods. Sci Rep 2016; 6:23378. [PMID: 26988733 PMCID: PMC4796899 DOI: 10.1038/srep23378] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 03/04/2016] [Indexed: 01/27/2023] Open
Abstract
The diffusion properties of H(+) in ZnO nanorods are investigated before and after 20 MeV proton beam irradiation by using (1)H nuclear magnetic resonance (NMR) spectroscopy. Herein, we unambiguously observe that the implanted protons occupy thermally unstable site of ZnO, giving rise to a narrow NMR line at 4.1 ppm. The activation barrier of the implanted protons was found to be 0.46 eV by means of the rotating-frame spin-lattice relaxation measurements, apparently being interstitial hydrogens. High-energy beam irradiation also leads to correlated jump diffusion of the surface hydroxyl group of multiple lines at ~1 ppm, implying the presence of structural disorder at the ZnO surface.
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Affiliation(s)
- Jun Kue Park
- Korea Multi-purpose Accelerator Complex, Korea Atomic Energy Research Institute, Gyeongju 38180, Korea.,Korea University of Science and Technology, Daejon 34113, Korea
| | - Hyeok-Jung Kwon
- Korea Multi-purpose Accelerator Complex, Korea Atomic Energy Research Institute, Gyeongju 38180, Korea.,Korea University of Science and Technology, Daejon 34113, Korea
| | - Cheol Eui Lee
- Department of Physics, Korea University, Seoul 02841, Korea
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Vanpoucke DEP. Modeling 1D structures on semiconductor surfaces: synergy of theory and experiment. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:133001. [PMID: 24599293 DOI: 10.1088/0953-8984/26/13/133001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Atomic scale nanowires attract enormous interest in a wide range of fields. On the one hand, due to their quasi-one-dimensional nature, they can act as an experimental testbed for exotic physics: Peierls instability, charge density waves, and Luttinger liquid behavior. On the other hand, due to their small size, they are of interest not only for future device applications in the micro-electronics industry, but also for applications regarding molecular electronics. This versatile nature makes them interesting systems to produce and study, but their size and growth conditions push both experimental production and theoretical modeling to their limits. In this review, modeling of atomic scale nanowires on semiconductor surfaces is discussed, focusing on the interplay between theory and experiment. The current state of modeling efforts on Pt- and Au-induced nanowires on Ge(001) is presented, indicating their similarities and differences. Recently discovered nanowire systems (Ir, Co, Sr) on the Ge(001) surface are also touched upon. The importance of scanning tunneling microscopy as a tool for direct comparison of theoretical and experimental data is shown, as is the power of density functional theory as an atomistic simulation approach. It becomes clear that complementary strengths of theoretical and experimental investigations are required for successful modeling of the atomistic nanowires, due to their complexity.
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Affiliation(s)
- Danny E P Vanpoucke
- Center for Molecular Modeling, Ghent University, Technologiepark 903, 9053 Zwijnaarde, Belgium
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Cowern NEB, Simdyankin S, Ahn C, Bennett NS, Goss JP, Hartmann JM, Pakfar A, Hamm S, Valentin J, Napolitani E, De Salvador D, Bruno E, Mirabella S. Extended point defects in crystalline materials: Ge and Si. PHYSICAL REVIEW LETTERS 2013; 110:155501. [PMID: 25167283 DOI: 10.1103/physrevlett.110.155501] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Indexed: 06/03/2023]
Abstract
B diffusion measurements are used to probe the basic nature of self-interstitial point defects in Ge. We find two distinct self-interstitial forms--a simple one with low entropy and a complex one with entropy ∼30 k at the migration saddle point. The latter dominates diffusion at high temperature. We propose that its structure is similar to that of an amorphous pocket--we name it a morph. Computational modeling suggests that morphs exist in both self-interstitial and vacancylike forms, and are crucial for diffusion and defect dynamics in Ge, Si, and probably many other crystalline solids.
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Affiliation(s)
- N E B Cowern
- School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - S Simdyankin
- School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - C Ahn
- School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - N S Bennett
- School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - J P Goss
- School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - J-M Hartmann
- CEA, LETI, Minatec Campus, 38054 Grenoble, France
| | - A Pakfar
- ST Microelectronics, 850 rue Jean Monnet, 38920 Crolles, France
| | - S Hamm
- Mattson Thermal Products GmbH, Daimlerstrasse 10, 89160 Dornstadt, Germany
| | - J Valentin
- Probion Analysis, 37 rue de Fontenay, 92220 Bagneux, France
| | - E Napolitani
- CNR-IMM-MATIS and Dipartimento di Fisica, Università di Padova, Via Marzolo 8, 35131 Padova, Italy
| | - D De Salvador
- CNR-IMM-MATIS and Dipartimento di Fisica, Università di Padova, Via Marzolo 8, 35131 Padova, Italy
| | - E Bruno
- CNR-IMM-MATIS and Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania, Italy
| | - S Mirabella
- CNR-IMM-MATIS and Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania, Italy
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Muzychenko DA, Schouteden K, Panov VI, Van Haesendonck C. Formation of Co/Ge intermixing layers after Co deposition on Ge(111)2 × 1 surfaces. NANOTECHNOLOGY 2012; 23:435605. [PMID: 23059653 DOI: 10.1088/0957-4484/23/43/435605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The formation of a novel surface reconstruction upon Co deposition on freshly cleaved Ge(111)2 × 1 surfaces is studied by means of scanning tunneling microscopy (STM) at 4.5 K. Previously we demonstrated that at this low substrate temperature the deposited Co atoms remain immobile after they become embedded underneath the Ge(111)2 × 1 surface. We now demonstrate that at higher substrate temperatures the embedded Co atoms are able to diffuse below the surface in a direction parallel to the upper π-bonded chain rows. This one-dimensional temperature-induced mobility results in subsurface accumulation of Co atoms at atomic steps, at domain boundaries and on atomically flat Ge terraces at, e.g., vacancies or adatoms, where reconstructed Co/Ge intermixing layers are formed. Voltage dependent STM images reveal that the Co related surface reconstruction locally exhibits an ordered atomic structure with the same inter-atomic distance as that of the initial 2 × 1 reconstructed pure Ge(111) surface. On the other hand, the presence of the Co results in a doubling of the periodicity along the [21[overline]1[overline]] direction in the STM images, which can be related to the modified electronic properties of the π-bonded chains.
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Affiliation(s)
- D A Muzychenko
- Faculty of Physics, Moscow State University, 119991 Moscow, Russia.
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Wang H, Chroneos A, Dimoulas A, Schwingenschlögl U. Interaction of oxygen vacancies in yttrium germanates. Phys Chem Chem Phys 2012; 14:14630-4. [DOI: 10.1039/c2cp42380d] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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