1
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Chasapoglou S, Kokkoris M, Vlastou R, Diakaki M, Michalopoulou V, Kalamara A, Gkatis G, Stamatopoulos A, Axiotis M, Harissopulos S, Lagoyannis A, Savva MI, Vasilopoulou T, Lederer-Woods C, Patronis N, Kaperoni K. On the accuracy of cross-section measurements of neutron-induced reactions using the activation technique with natural tar gets: The case of Ge at E n=17.9 MeV. Appl Radiat Isot 2024; 203:111077. [PMID: 37925902 DOI: 10.1016/j.apradiso.2023.111077] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 10/18/2023] [Accepted: 10/19/2023] [Indexed: 11/07/2023]
Abstract
Several cross-section measurements of neutron-induced reactions on Ge found in literature, are performed utilizing natGe targets. The production of the same residual nucleus as the measured one might occur as a result of the unavoidable presence of neighboring isotopes in the same target, acting as a contamination. Corrections must be made based on theoretical calculations and models in order to resolve this problem. The accuracy and limits of a methodology for these "theoretical corrections" are investigated in this work using isotopically enriched targets, which can produce very accurate results without the need for such corrections. Experimental cross-section measurements have been made for the 76Ge(n,2n)75Ge, 72Ge(n,α)69mZn and 72Ge(n,p)72Ga reactions, via the activation technique, with the 27Al(n,α)24Na reaction used as reference, employing both a natGe and isotopically enriched Ge targets. The 3H(d,n)4He (D-T) reaction was used for producing the quasi-monoenergetic neutron beam in the 5.5 MV Tandem Accelerator Laboratory of the National Centre for Scientific Research "Demokritos" in Athens, Greece, at an incident deuteron beam energy of 2.9 MeV. Using HPGe detectors, γ-ray spectroscopy was applied to determine the induced γ-ray activity of the residual nuclei.
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Affiliation(s)
- S Chasapoglou
- Department of Physics, National Technical University of Athens, Zografou Campus, Athens, 15772, Greece.
| | - M Kokkoris
- Department of Physics, National Technical University of Athens, Zografou Campus, Athens, 15772, Greece
| | - R Vlastou
- Department of Physics, National Technical University of Athens, Zografou Campus, Athens, 15772, Greece
| | - M Diakaki
- Department of Physics, National Technical University of Athens, Zografou Campus, Athens, 15772, Greece
| | - V Michalopoulou
- Department of Physics, National Technical University of Athens, Zografou Campus, Athens, 15772, Greece; European Organization for Nuclear Research (CERN), Geneva, Switzerland
| | - A Kalamara
- Institute of Nuclear and Radiological Sciences, Technology, Energy & Safety, N.C.S.R. "Demokritos", Athens, Greece; Institute of Nanoscience and Nanotechnology, N.C.S.R. "Demokritos", Athens, Greece
| | - G Gkatis
- Department of Physics, National Technical University of Athens, Zografou Campus, Athens, 15772, Greece; CEA/DES/IRESNE/DER/SPRC/LEPh, Cadarache, Saint Paul Lez Durance, France
| | - A Stamatopoulos
- Department of Physics, National Technical University of Athens, Zografou Campus, Athens, 15772, Greece; Physics Division, Los Alamos National Laboratory, Los Alamos, NM, United States
| | - M Axiotis
- Tandem Accelerator Laboratory, Institute of Nuclear and Particle Physics, N.C.S.R. "Demokritos", Athens, Greece
| | - S Harissopulos
- Tandem Accelerator Laboratory, Institute of Nuclear and Particle Physics, N.C.S.R. "Demokritos", Athens, Greece
| | - A Lagoyannis
- Tandem Accelerator Laboratory, Institute of Nuclear and Particle Physics, N.C.S.R. "Demokritos", Athens, Greece
| | - M I Savva
- Institute of Nuclear and Radiological Sciences, Technology, Energy & Safety, N.C.S.R. "Demokritos", Athens, Greece
| | - T Vasilopoulou
- Institute of Nuclear and Radiological Sciences, Technology, Energy & Safety, N.C.S.R. "Demokritos", Athens, Greece
| | - C Lederer-Woods
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - N Patronis
- Department of Physics, University of Ioannina, Ioannina, Greece
| | - K Kaperoni
- Department of Physics, National Technical University of Athens, Zografou Campus, Athens, 15772, Greece
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2
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Liu Y, Lüttjohann S, Vianello A, Lorenz C, Liu F, Vollertsen J. Detecting small microplastics down to 1.3 μm using lar ge area ATR-FTIR. Mar Pollut Bull 2024; 198:115795. [PMID: 38006870 DOI: 10.1016/j.marpolbul.2023.115795] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 10/18/2023] [Accepted: 11/12/2023] [Indexed: 11/27/2023]
Abstract
Large area attenuated total reflectance-Fourier transform infrared spectroscopy (LAATR-FTIR) is introduced as a novel technique for detecting small microplastics (MPs) down to 1.3 μm. Two different LAATR units, one with a zinc selenide (ZnSe) and one with a germanium (Ge) crystal, were used to detect reference MPs < 20 μm, and MPs in marine water samples, and compared with μ-FTIR in transmission mode. The LAATR units performed well in identifying small MPs down to 1.3 μm. However, they were poorly suited for large MPs as uneven particle thickness resulted in uneven contact between crystal and particle, misinterpreting large MPs as many small MPs. However, for more homogeneous matrices, the technique was promising. Further assessment indicated that there was little difference in spectra quality between transmission mode and LAATR mode. All in all, while LAATR units struggle to substitute transmission mode, it provides additional information and valuable information on small MPs.
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Affiliation(s)
- Yuanli Liu
- Department of the Built Environment, Aalborg University, Thomas Manns Vej 23, 9220 Aalborg, Denmark; College of Environmental and Biological Engineering, Putian University, Putian 351100, China; Fujian Provincial Key Laboratory of Ecology-Toxicological Effects and Control for Emerging Contaminants, Putian University, Putian 351100, China; Key Laboratory of Ecological Environment and Information Atlas, Fujian Provincial University, Putian 351100, Fujian, China.
| | - Stephan Lüttjohann
- Bruker Optics GmbH & Co. KG, Rudolf-Plank-Straße 27, 76275 Ettlingen, Germany
| | - Alvise Vianello
- Department of the Built Environment, Aalborg University, Thomas Manns Vej 23, 9220 Aalborg, Denmark
| | - Claudia Lorenz
- Department of the Built Environment, Aalborg University, Thomas Manns Vej 23, 9220 Aalborg, Denmark
| | - Fan Liu
- Department of the Built Environment, Aalborg University, Thomas Manns Vej 23, 9220 Aalborg, Denmark
| | - Jes Vollertsen
- Department of the Built Environment, Aalborg University, Thomas Manns Vej 23, 9220 Aalborg, Denmark
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3
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Xie L, Zhu H, Zhang Y, Ai X, Li J, Wang G, Liu J, Du A, Yang H, Yin X, Huang W, Li C, Li Y, Wang Q, Lu S, Kong Z, Xiang J, Du Y, Luo J, Li J, Radamson HH, Wang W, Ye T. Demonstration of Germanium Vertical Gate-All-Around Field-Effect Transistors Featured by Self-Aligned High-κ Metal Gates with Record High Performance. ACS Nano 2023; 17:22259-22267. [PMID: 37823534 DOI: 10.1021/acsnano.3c02518] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
A special Ge nanowire/nanosheet (NW/NS) p-type vertical sandwich gate-all-around (GAA) field-effect transistor (FET) (Ge NW/NS pVSAFET) with self-aligned high-κ metal gates (HKMGs) is proposed. The Ge pVSAFETs were fabricated by high-quality GeSi/Ge epitaxy, an exclusively developed self-limiting isotropic quasi atomic layer etching (qALE) of Ge selective to both GeSi and the (111) plane, top-drain implantation, and ozone postoxidation (OPO) channel passivation. The Ge pVSAFETs, which have hourglass-shaped (111) channels with the smallest size range from 5 to 20 nm formed by qALE, have reached a record high Ion of ∼291 μA/μm and exhibited good short channel effects (SCEs) control. The integration flow is compatible with mainstream CMOS processes, and Ge pVSAFETs with precise control of gate lengths/channel sizes were obtained.
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Affiliation(s)
- Lu Xie
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huilong Zhu
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongkui Zhang
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Xuezheng Ai
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Junjie Li
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Guilei Wang
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Jinbiao Liu
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Anyan Du
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Hong Yang
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Xiaogen Yin
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Weixing Huang
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chen Li
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yangyang Li
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qi Wang
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Shunshun Lu
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Zhenzhen Kong
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Jinjuan Xiang
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Yong Du
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Jun Luo
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Junfeng Li
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Henry H Radamson
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenwu Wang
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Tianchun Ye
- Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
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4
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Ngoc HV, Thuy HTP. Electrical and optical properties of C, Ge-doped armchair silicene nanoribbons applied in optoelectronics. J Phys Condens Matter 2023. [PMID: 37321257 DOI: 10.1088/1361-648x/acdebe] [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] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
With the continuous development of nanotechnology, the search for new material structures plays a crucial role. Silicene nanoribbons are one-dimensional materials that hold promise for numerous potential applications in the future. The electric and optical properties of C, Ge-doped armchair silicene nanoribbons are investigated in this study using Density Functional Theory (DFT). All the doped configurations are stable and maintain the honeycomb hexagonal structure after optimization. Doping with C yields flatter structures, while doping with Ge yields larger buckling heights. The C 1-1 doping configuration is highlighted because its band gap is extended up to 2.35 eV, making it an ideal candidate for potential optoelectronic applications. The charge distribution, charge density difference, and hybridization of multiple orbitals are also systematically studied. The optical properties reveal the differences between C and Ge doping, with a clear anisotropy observed. Strong absorption occurs at high electromagnetic wave energies,, while the absorption coefficient rapidly decreases in the long-wavelength range. The study of electron-hole density shows good agreement with the energy band structure, where electron-hole pairs only exist when the excitation energy is greater than the bandgap width, and not all excitation energy values give rise to electron-hole pairs. This study contributes a small part to creating potential applications in nanotechnology.
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Affiliation(s)
- Hoang Van Ngoc
- Thu Dau Mot University, No. 06 Tran Van On street, Thu Dau Mot, 820000, VIET NAM
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5
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Frigeri P, Gombia E, Bosi M, Trevisi G, Seravalli L, Ferrari C. Electrical properties and chemiresistive response to 2,4,6 trinitrotoluene vapours of large area arrays of Ge nanowires. Nanoscale Res Lett 2023; 18:5. [PMID: 36749462 DOI: 10.1186/s11671-023-03780-1] [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] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 01/27/2023] [Indexed: 05/24/2023]
Abstract
We study the electrical and morphological properties of random arrays of Ge nanowires (NW) deposited on sapphire substrates. NW-based devices were fabricated with the aim of developing chemiresistive-type sensors for the detection of explosive vapours. We present the results obtained on pristine and annealed NWs and, focusing on the different phenomenology observed, we discuss the critical role played by NW-NW junctions on the electrical conduction and sensing performances. A mechanism is proposed to explain the high efficiency of the annealed arrays of NWs in detecting 2,4,6 trinitrotoluene vapours. This study shows the promising potential of Ge NW-based sensors in the field of civil security.
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Affiliation(s)
- Paola Frigeri
- IMEM-CNR Institute, Parco Area delle Scienze 37/A, 43124, Parma, Italy.
| | - Enos Gombia
- IMEM-CNR Institute, Parco Area delle Scienze 37/A, 43124, Parma, Italy
| | - Matteo Bosi
- IMEM-CNR Institute, Parco Area delle Scienze 37/A, 43124, Parma, Italy
| | - Giovanna Trevisi
- IMEM-CNR Institute, Parco Area delle Scienze 37/A, 43124, Parma, Italy
| | - Luca Seravalli
- IMEM-CNR Institute, Parco Area delle Scienze 37/A, 43124, Parma, Italy
| | - Claudio Ferrari
- IMEM-CNR Institute, Parco Area delle Scienze 37/A, 43124, Parma, Italy
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6
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Lidsky D, Cain JM, Hutchins-Delgado T, Lu TM. Inverse metal-assisted chemical etching of germanium with gold and hydrogen peroxide. Nanotechnology 2022; 34:065302. [PMID: 35835063 DOI: 10.1088/1361-6528/ac810c] [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] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
Metal-assisted chemical etching (MACE) is a flexible technique for texturing the surface of semiconductors. In this work, we study the spatial variation of the etch profile, the effect of angular orientation relative to the crystallographic planes, and the effect of doping type. We employ gold in direct contact with germanium as the metal catalyst, and dilute hydrogen peroxide solution as the chemical etchant. With this catalyst-etchant combination, we observe inverse-MACE, where the area directly under gold is not etched, but the neighboring, exposed germanium experiences enhanced etching. This enhancement in etching decays exponentially with the lateral distance from the gold structure. An empirical formula for the gold-enhanced etching depth as a function of lateral distance from the edge of the gold film is extracted from the experimentally measured etch profiles. The lateral range of enhanced etching is approximately 10-20μm and is independent of etchant concentration. At length scales beyond a few microns, the etching enhancement is independent of the orientation with respect to the germanium crystallographic planes. The etch rate as a function of etchant concentration follows a power law with exponent smaller than 1. The observed etch rates and profiles are independent of whether the germanium substrate is n-type, p-type, or nearly intrinsic.
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Affiliation(s)
- D Lidsky
- Sandia National Laboratories, Albuquerque, NM 87185, United States of America
| | - J M Cain
- Sandia National Laboratories, Albuquerque, NM 87185, United States of America
| | - T Hutchins-Delgado
- Sandia National Laboratories, Albuquerque, NM 87185, United States of America
| | - T M Lu
- Sandia National Laboratories, Albuquerque, NM 87185, United States of America
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM 87123, United States of America
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7
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Song L, Tang L, Hao Q, Teng KS, Lv H, Wang J, Feng J, Zhou Y, He W, Wang W. Broadband photodetector based on SnTe nanofilm/n- Ge heterostructure. Nanotechnology 2022; 33:425203. [PMID: 35830829 DOI: 10.1088/1361-6528/ac80cc] [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] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
Combining novel two-dimensional materials with traditional semiconductors to form heterostructures for photoelectric detection have attracted great attention due to their excellent photoelectric properties. In this study, we reported the formation of a heterostructure comprising of tin telluride (SnTe) and germanium (Ge) by a simple and efficient one-step magnetron sputtering technique. A photodetector was fabricated by sputtering a nanofilm of SnTe on to a pre-masked n-Ge substrate.J-Vmeasurements obtained from the SnTe/n-Ge photodetector demonstrated diode and photovoltaic characteristics in the visible to near-infrared (NIR) band (i.e. 400-2050 nm). Under NIR illumination at 850 nm with an optical power density of 13.81 mW cm-2, the SnTe/n-Ge photodetector exhibited a small open-circuit voltage of 0.05 V. It also attained a high responsivity (R) and detectivity (D*) of 617.34 mA W-1(at bias voltage of -0.5 V) and 2.33 × 1011cmHz1/2W-1(at zero bias), respectively. Therefore, SnTe nanofilm/n-Ge heterostructure is highly suitable for used as low-power broadband photodetector due to its excellent performances and simple device configuration.
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Affiliation(s)
- Liyuan Song
- The Laboratory of Photonics Information Technology, Ministry of Industry and Information Technology, School of Optics and Photonics, Beijing Institute of Technology, Beijing 100081, People's Republic of China
- Kunming Institute of Physics, Kunming 650223, People's Republic of China
- Yunnan Key Laboratory of Advanced Photoelectronic Materials & Devices, Kunming 650223, People's Republic of China
| | - Libin Tang
- The Laboratory of Photonics Information Technology, Ministry of Industry and Information Technology, School of Optics and Photonics, Beijing Institute of Technology, Beijing 100081, People's Republic of China
- Kunming Institute of Physics, Kunming 650223, People's Republic of China
- Yunnan Key Laboratory of Advanced Photoelectronic Materials & Devices, Kunming 650223, People's Republic of China
| | - Qun Hao
- The Laboratory of Photonics Information Technology, Ministry of Industry and Information Technology, School of Optics and Photonics, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Kar Seng Teng
- Department of Electronic and Electrical Engineering, Swansea University, Bay Campus, Fabian Way, Swansea SA1 8EN, United Kingdom
| | - Hao Lv
- Kunming Institute of Physics, Kunming 650223, People's Republic of China
| | - Jingyu Wang
- Kunming Institute of Physics, Kunming 650223, People's Republic of China
| | - Jiangmin Feng
- Kunming Institute of Physics, Kunming 650223, People's Republic of China
| | - Yan Zhou
- Kunming Institute of Physics, Kunming 650223, People's Republic of China
| | - Wenjin He
- Kunming Institute of Physics, Kunming 650223, People's Republic of China
| | - Wei Wang
- Kunming Institute of Physics, Kunming 650223, People's Republic of China
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8
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Thornton CS, Tuttle B, Turner E, Law ME, Pantelides ST, Wang GT, Jones KS. The Diffusion Mechanism of Ge During Oxidation of Si/SiGe Nanofins. ACS Appl Mater Interfaces 2022; 14:29422-29430. [PMID: 35706336 DOI: 10.1021/acsami.2c05470] [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] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
A recently discovered, enhanced Ge diffusion mechanism along the oxidizing interface of Si/SiGe nanostructures has enabled the formation of single-crystal Si nanowires and quantum dots embedded in a defect-free, single-crystal SiGe matrix. Here, we report oxidation studies of Si/SiGe nanofins aimed at gaining a better understanding of this novel diffusion mechanism. A superlattice of alternating Si/Si0.7Ge0.3 layers was grown and patterned into fins. After oxidation of the fins, the rate of Ge diffusion down the Si/SiO2 interface was measured through the analysis of HAADF-STEM images. The activation energy for the diffusion of Ge down the sidewall was found to be 1.1 eV, which is less than one-quarter of the activation energy previously reported for Ge diffusion in bulk Si. Through a combination of experiments and DFT calculations, we propose that the redistribution of Ge occurs by diffusion along the Si/SiO2 interface followed by a reintroduction into substitutional positions in the crystalline Si.
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Affiliation(s)
- Chappel S Thornton
- Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611, United States
| | - Blair Tuttle
- Department of Physics, The Pennsylvania State University- Behrend, Erie, Pennsylvania 16563, United States
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37212, United States
| | - Emily Turner
- Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611, United States
| | - Mark E Law
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, Florida 32611, United States
| | - Sokrates T Pantelides
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37212, United States
- Department of Electrical and Computer Engineering, Vanderbilt University, Nashville, Tennessee 37212, United States
| | - George T Wang
- Advanced Materials Sciences, Sandia National Laboratories, Albuquerque, New Mexico 87158, United States
| | - Kevin S Jones
- Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611, United States
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9
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Steinmann C, Sauer SPA. The aug-cc-pVTZ-J basis set for the p-block fourth-row elements Ga, Ge, As, Se, and Br. Magn Reson Chem 2021; 59:1134-1145. [PMID: 33929770 DOI: 10.1002/mrc.5166] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/24/2021] [Accepted: 04/26/2021] [Indexed: 06/12/2023]
Abstract
The aug-cc-pVTZ-J basis set family is extended to include the fourth-row p-block elements Ga, Ge, As, Se, and Br. We use the established approach outlined by Sauer and coworkers (J. Chem. Phys. 115, 1324 [2001], J. Chem. Phys. 133, 054308 [2010], J. Chem. Theory Comput. 7, 4070 [2011], and J. Chem. Theory Comput. 7, 4077 [2011]) where the completely uncontracted aug-cc-pVTZ basis set is saturated with tight s-, p-, d-, and f-functions to form the aug-cc-pVTZ-Juc basis set for the tested elements. The saturation is carried out on the simplest hydrides possible for the tested elements GaH, GeH4 , AsH3 , H2 Se, and HBr until an improvement is less than 0.01% for all s-, p-, and d-functions added. f-Functions are added to an improvement less than or equal to 1.0% due to the computational expense these functions add. The saturated aug-cc-pVTZ-Juc (26s16p12d5f) is then recontracted using the molecular orbital coefficients from self-consistent field calculations on the simple hydrides to improve computational efficiency. During contraction of the basis set, we observe that the linear hydrogen bromide molecule has a slower convergence than the other tested molecules which sets a limit on the accuracy obtained. All calculations with the contracted aug-cc-pVTZ-J [17s10p7d5f] gives results that are within 1.0% of the uncontracted results at considerable computational savings.
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Affiliation(s)
- Casper Steinmann
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Stephan P A Sauer
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
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10
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Du Y, Wang G, Miao Y, Xu B, Li B, Kong Z, Yu J, Zhao X, Lin H, Su J, Han J, Liu J, Dong Y, Wang W, Radamson HH. Strain Modulation of Selectively and/or Globally Grown Ge Layers. Nanomaterials (Basel) 2021; 11:nano11061421. [PMID: 34071167 PMCID: PMC8229019 DOI: 10.3390/nano11061421] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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] [Received: 04/28/2021] [Revised: 05/19/2021] [Accepted: 05/21/2021] [Indexed: 11/16/2022]
Abstract
This article presents a novel method to grow a high-quality compressive-strain Ge epilayer on Si using the selective epitaxial growth (SEG) applying the RPCVD technique. The procedures are composed of a global growth of Ge layer on Si followed by a planarization using CMP as initial process steps. The growth parameters of the Ge layer were carefully optimized and after cycle-annealing treatments, the threading dislocation density (TDD) was reduced to 3 × 107 cm−2. As a result of this process, a tensile strain of 0.25% was induced, whereas the RMS value was as low as 0.81 nm. Later, these substrates were covered by an oxide layer and patterned to create trenches for selective epitaxy growth (SEG) of the Ge layer. In these structures, a type of compressive strain was formed in the SEG Ge top layer. The strain amount was −0.34%; meanwhile, the TDD and RMS surface roughness were 2 × 106 cm−2 and 0.68 nm, respectively. HRXRD and TEM results also verified the existence of compressive strain in selectively grown Ge layer. In contrast to the tensile strained Ge layer (globally grown), enhanced PL intensity by a factor of more than 2 is partially due to the improved material quality. The significantly high PL intensity is attributed to the improved crystalline quality of the selectively grown Ge layer. The change in direct bandgap energy of PL was observed, owing to the compressive strain introduced. Hall measurement shows that a selectively grown Ge layer possesses room temperature hole mobility up to 375 cm2/Vs, which is approximately 3 times larger than that of the Ge (132 cm2/Vs). Our work offers fundamental guidance for the growth of high-quality and compressive strain Ge epilayer on Si for future Ge-based optoelectronics integration applications.
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Affiliation(s)
- Yong Du
- Key laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (B.X.); (Z.K.); (J.Y.); (X.Z.); (H.L.); (J.S.); (J.H.); (J.L.); (Y.D.); (W.W.)
- Institute of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guilei Wang
- Key laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (B.X.); (Z.K.); (J.Y.); (X.Z.); (H.L.); (J.S.); (J.H.); (J.L.); (Y.D.); (W.W.)
- Institute of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
- Research and Development Center of Optoelectronic Hybrid IC, Guangdong Greater Bay Area Institute of Integrated Circuit and System, Guangzhou 510535, China;
- Correspondence: (G.W.); (Y.M.); (H.H.R.); Tel.: +86-010-8299-5793 (G.W.)
| | - Yuanhao Miao
- Key laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (B.X.); (Z.K.); (J.Y.); (X.Z.); (H.L.); (J.S.); (J.H.); (J.L.); (Y.D.); (W.W.)
- Research and Development Center of Optoelectronic Hybrid IC, Guangdong Greater Bay Area Institute of Integrated Circuit and System, Guangzhou 510535, China;
- Correspondence: (G.W.); (Y.M.); (H.H.R.); Tel.: +86-010-8299-5793 (G.W.)
| | - Buqing Xu
- Key laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (B.X.); (Z.K.); (J.Y.); (X.Z.); (H.L.); (J.S.); (J.H.); (J.L.); (Y.D.); (W.W.)
- Institute of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ben Li
- Research and Development Center of Optoelectronic Hybrid IC, Guangdong Greater Bay Area Institute of Integrated Circuit and System, Guangzhou 510535, China;
| | - Zhenzhen Kong
- Key laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (B.X.); (Z.K.); (J.Y.); (X.Z.); (H.L.); (J.S.); (J.H.); (J.L.); (Y.D.); (W.W.)
- Institute of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiahan Yu
- Key laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (B.X.); (Z.K.); (J.Y.); (X.Z.); (H.L.); (J.S.); (J.H.); (J.L.); (Y.D.); (W.W.)
- Institute of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuewei Zhao
- Key laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (B.X.); (Z.K.); (J.Y.); (X.Z.); (H.L.); (J.S.); (J.H.); (J.L.); (Y.D.); (W.W.)
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
| | - Hongxiao Lin
- Key laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (B.X.); (Z.K.); (J.Y.); (X.Z.); (H.L.); (J.S.); (J.H.); (J.L.); (Y.D.); (W.W.)
- Research and Development Center of Optoelectronic Hybrid IC, Guangdong Greater Bay Area Institute of Integrated Circuit and System, Guangzhou 510535, China;
| | - Jiale Su
- Key laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (B.X.); (Z.K.); (J.Y.); (X.Z.); (H.L.); (J.S.); (J.H.); (J.L.); (Y.D.); (W.W.)
| | - Jianghao Han
- Key laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (B.X.); (Z.K.); (J.Y.); (X.Z.); (H.L.); (J.S.); (J.H.); (J.L.); (Y.D.); (W.W.)
| | - Jinbiao Liu
- Key laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (B.X.); (Z.K.); (J.Y.); (X.Z.); (H.L.); (J.S.); (J.H.); (J.L.); (Y.D.); (W.W.)
- Institute of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan Dong
- Key laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (B.X.); (Z.K.); (J.Y.); (X.Z.); (H.L.); (J.S.); (J.H.); (J.L.); (Y.D.); (W.W.)
| | - Wenwu Wang
- Key laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (B.X.); (Z.K.); (J.Y.); (X.Z.); (H.L.); (J.S.); (J.H.); (J.L.); (Y.D.); (W.W.)
- Institute of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Henry H. Radamson
- Key laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (B.X.); (Z.K.); (J.Y.); (X.Z.); (H.L.); (J.S.); (J.H.); (J.L.); (Y.D.); (W.W.)
- Institute of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
- Research and Development Center of Optoelectronic Hybrid IC, Guangdong Greater Bay Area Institute of Integrated Circuit and System, Guangzhou 510535, China;
- Department of Electronics Design, Mid Sweden University, Holmgatan 10, 85170 Sundsvall, Sweden
- Correspondence: (G.W.); (Y.M.); (H.H.R.); Tel.: +86-010-8299-5793 (G.W.)
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11
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Du Y, Kong Z, Toprak MS, Wang G, Miao Y, Xu B, Yu J, Li B, Lin H, Han J, Dong Y, Wang W, Radamson HH. Investigation of the Heteroepitaxial Process Optimization of Ge Layers on Si (001) by RPCVD. Nanomaterials (Basel) 2021; 11:nano11040928. [PMID: 33917367 PMCID: PMC8067383 DOI: 10.3390/nano11040928] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [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] [Received: 03/01/2021] [Revised: 03/19/2021] [Accepted: 03/30/2021] [Indexed: 02/06/2023]
Abstract
This work presents the growth of high-quality Ge epilayers on Si (001) substrates using a reduced pressure chemical vapor deposition (RPCVD) chamber. Based on the initial nucleation, a low temperature high temperature (LT-HT) two-step approach, we systematically investigate the nucleation time and surface topography, influence of a LT-Ge buffer layer thickness, a HT-Ge growth temperature, layer thickness, and high temperature thermal treatment on the morphological and crystalline quality of the Ge epilayers. It is also a unique study in the initial growth of Ge epitaxy; the start point of the experiments includes Stranski-Krastanov mode in which the Ge wet layer is initially formed and later the growth is developed to form nuclides. Afterwards, a two-dimensional Ge layer is formed from the coalescing of the nuclides. The evolution of the strain from the beginning stage of the growth up to the full Ge layer has been investigated. Material characterization results show that Ge epilayer with 400 nm LT-Ge buffer layer features at least the root mean square (RMS) value and it's threading dislocation density (TDD) decreases by a factor of 2. In view of the 400 nm LT-Ge buffer layer, the 1000 nm Ge epilayer with HT-Ge growth temperature of 650 °C showed the best material quality, which is conducive to the merging of the crystals into a connected structure eventually forming a continuous and two-dimensional film. After increasing the thickness of Ge layer from 900 nm to 2000 nm, Ge surface roughness decreased first and then increased slowly (the RMS value for 1400 nm Ge layer was 0.81 nm). Finally, a high-temperature annealing process was carried out and high-quality Ge layer was obtained (TDD=2.78 × 107 cm-2). In addition, room temperature strong photoluminescence (PL) peak intensity and narrow full width at half maximum (11 meV) spectra further confirm the high crystalline quality of the Ge layer manufactured by this optimized process. This work highlights the inducing, increasing, and relaxing of the strain in the Ge buffer and the signature of the defect formation.
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Affiliation(s)
- Yong Du
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (Z.K.); (Y.M.); (B.X.); (J.Y.); (H.L.); (J.H.); (Y.D.); (W.W.)
- Institute of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhenzhen Kong
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (Z.K.); (Y.M.); (B.X.); (J.Y.); (H.L.); (J.H.); (Y.D.); (W.W.)
- Institute of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Muhammet S. Toprak
- Department of Materials and Nano Physics, School of Information and Communication Technology, KTH Royal Institute of Technology, Isafjordsgatan 22, Kista, SE-164 40, Sweden;
| | - Guilei Wang
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (Z.K.); (Y.M.); (B.X.); (J.Y.); (H.L.); (J.H.); (Y.D.); (W.W.)
- Institute of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
- Research and Development Center of Optoelectronic Hybrid IC, Guangdong Greater Bay Area Institute of Integrated Circuit and System, Guangzhou 510535, China;
- Correspondence: (G.W.); (H.H.R.); Tel.: +86-010-8299-5793 (G.W.)
| | - Yuanhao Miao
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (Z.K.); (Y.M.); (B.X.); (J.Y.); (H.L.); (J.H.); (Y.D.); (W.W.)
- Research and Development Center of Optoelectronic Hybrid IC, Guangdong Greater Bay Area Institute of Integrated Circuit and System, Guangzhou 510535, China;
| | - Buqing Xu
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (Z.K.); (Y.M.); (B.X.); (J.Y.); (H.L.); (J.H.); (Y.D.); (W.W.)
- Institute of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiahan Yu
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (Z.K.); (Y.M.); (B.X.); (J.Y.); (H.L.); (J.H.); (Y.D.); (W.W.)
- Institute of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ben Li
- Research and Development Center of Optoelectronic Hybrid IC, Guangdong Greater Bay Area Institute of Integrated Circuit and System, Guangzhou 510535, China;
| | - Hongxiao Lin
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (Z.K.); (Y.M.); (B.X.); (J.Y.); (H.L.); (J.H.); (Y.D.); (W.W.)
| | - Jianghao Han
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (Z.K.); (Y.M.); (B.X.); (J.Y.); (H.L.); (J.H.); (Y.D.); (W.W.)
| | - Yan Dong
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (Z.K.); (Y.M.); (B.X.); (J.Y.); (H.L.); (J.H.); (Y.D.); (W.W.)
| | - Wenwu Wang
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (Z.K.); (Y.M.); (B.X.); (J.Y.); (H.L.); (J.H.); (Y.D.); (W.W.)
- Institute of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Henry H. Radamson
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China; (Y.D.); (Z.K.); (Y.M.); (B.X.); (J.Y.); (H.L.); (J.H.); (Y.D.); (W.W.)
- Institute of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
- Research and Development Center of Optoelectronic Hybrid IC, Guangdong Greater Bay Area Institute of Integrated Circuit and System, Guangzhou 510535, China;
- Department of Electronics Design, Mid Sweden University, Holmgatan 10, 85170 Sundsvall, Sweden
- Correspondence: (G.W.); (H.H.R.); Tel.: +86-010-8299-5793 (G.W.)
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12
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Le Faucheur S, Mertens J, Van Genderen E, Boullemant A, Fortin C, Campbell PGC. Development of Quantitative Ion Character-Activity Relationship Models to Address the Lack of Toxicological Data for Technology-Critical Elements. Environ Toxicol Chem 2021; 40:1139-1148. [PMID: 33315280 DOI: 10.1002/etc.4960] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 06/09/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
Recent industrial developments have resulted in an increase in the use of so-called technology-critical elements (TCEs), for which the potential impacts on aquatic biota remain to be evaluated. In the present study, quantitative ion character-activity relationships (QICARs) have been developed to relate intrinsic metal properties to their toxicity toward freshwater aquatic organisms. In total, 23 metal properties were tested as predictors of acute median effect concentration (EC50) values for 12 data-rich metals, for algae, daphnids, and fish (with and without species distinction). Simple and multiple linear regressions were developed using the toxicological data expressed as a function of the total dissolved metal concentrations. The best regressions were then tested by comparing the predicted EC50 values for the TCEs (germanium, indium, gold, and rhenium) and platinum group elements (iridium, platinum, palladium, rhodium, and ruthenium) with the few measured values that are available. The 8 "best" QICAR models (adjusted r2 > 0.6) used the covalent index as the predictor. For a given metal ion, this composite parameter is a measure of the importance of covalent interactions relative to ionic interactions. Toxicity was reasonably well predicted for most of the TCEs, with values falling within the 95% prediction intervals for the regressions of the measured versus predicted EC50 values. Exceptions included Au(I) (all test organisms), Au(III) (algae and fish), Pt(II) (algae, daphnids), Ru(III) (daphnids), and Rh(III) (daphnids, fish). We conclude that QICARs show potential as a screening tool to review toxicity data and flag "outliers," which might need further scrutiny, and as an interpolating or extrapolating tool to predict TCE toxicity. Environ Toxicol Chem 2021;40:1139-1148. © 2020 SETAC.
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Affiliation(s)
- Séverine Le Faucheur
- Université de Pau et des Pays de l'Adour, e2s-UPPA, IPREM, Pau, France, and University of Geneva, DEFSE, Uni Carl Vogt, Geneva, Switzerland
| | - Jelle Mertens
- European Precious Metals Federation, Brussels, Belgium
| | | | | | - Claude Fortin
- Institut National de la Recherche Scientifique, Centre Eau Terre Environnement, Québec, Québec, Canada
| | - Peter G C Campbell
- Institut National de la Recherche Scientifique, Centre Eau Terre Environnement, Québec, Québec, Canada
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Timò G, Calicchio M, Abagnale G, Armani N, Achilli E, Cornelli M, Annoni F, Schineller B, Andreani LC. Study of the Cross-Influence between III-V and IV Elements Deposited in the Same MOVPE Growth Chamber. Materials (Basel) 2021; 14:1066. [PMID: get='_blank'>33668771 DOI: 10.3390/ma14051066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/16/2021] [Accepted: 02/22/2021] [Indexed: 11/16/2022]
Abstract
We have deposited Ge, SiGe, SiGeSn, AlAs, GaAs, InGaP and InGaAs based structures in the same metalorganic vapor phase epitaxy (MOVPE) growth chamber, in order to study the effect of the cross influence between groups IV and III-V elements on the growth rate, background doping and morphology. It is shown that by adopting an innovative design of the MOVPE growth chamber and proper growth condition, the IV elements growth rate penalization due to As "carry over" can be eliminated and the background doping level in both IV and III-V semiconductors can be drastically reduced. In the temperature range 748-888 K, Ge and SiGe morphologies do not degrade when the semiconductors are grown in a III-V-contaminated MOVPE growth chamber. Critical morphology aspects have been identified for SiGeSn and III-Vs, when the MOVPE deposition takes place, respectively, in a As or Sn-contaminated MOVPE growth chamber. III-Vs morphologies are influenced by substrate type and orientation. The results are promising in view of the monolithic integration of group-IV with III-V compounds in multi-junction solar cells.
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Schiavon D, Litwin-Staszewska E, Jakieła R, Grzanka S, Perlin P. Effects of MOVPE Growth Conditions on GaN Layers Doped with Germanium. Materials (Basel) 2021; 14:ma14020354. [PMID: 33450822 PMCID: PMC7828268 DOI: 10.3390/ma14020354] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [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] [Received: 12/24/2020] [Revised: 01/08/2021] [Accepted: 01/11/2021] [Indexed: 11/18/2022]
Abstract
The effect of growth temperature and precursor flow on the doping level and surface morphology of Ge-doped GaN layers was researched. The results show that germanium is more readily incorporated at low temperature, high growth rate and high V/III ratio, thus revealing a similar behavior to what was previously observed for indium. V-pit formation can be blocked at high temperature but also at low V/III ratio, the latter of which however causing step bunching.
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Affiliation(s)
- Dario Schiavon
- Optoelectronic Devices Laboratory, Institute of High Pressure Physics, Polish Academy of Sciences, al. Sokołowska 29/37, 01-142 Warsaw, Poland; (S.G.); (P.P.)
- Correspondence:
| | - Elżbieta Litwin-Staszewska
- Laboratory of Nitride Semiconductor Physics, Institute of High Pressure Physics, Polish Academy of Sciences, al. Sokołowska 29/37, 01-142 Warsaw, Poland;
| | - Rafał Jakieła
- Laboratory of X-ray and Electron Microscopy Research, Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland;
| | - Szymon Grzanka
- Optoelectronic Devices Laboratory, Institute of High Pressure Physics, Polish Academy of Sciences, al. Sokołowska 29/37, 01-142 Warsaw, Poland; (S.G.); (P.P.)
| | - Piotr Perlin
- Optoelectronic Devices Laboratory, Institute of High Pressure Physics, Polish Academy of Sciences, al. Sokołowska 29/37, 01-142 Warsaw, Poland; (S.G.); (P.P.)
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15
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Prucnal S, Żuk J, Hübner R, Duan J, Wang M, Pyszniak K, Drozdziel A, Turek M, Zhou S. Electron Concentration Limit in Ge Doped by Ion Implantation and Flash Lamp Annealing. Materials (Basel) 2020; 13:E1408. [PMID: 32244923 DOI: 10.3390/ma13061408] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/13/2020] [Accepted: 03/16/2020] [Indexed: 01/09/2023]
Abstract
Controlled doping with an effective carrier concentration higher than 1020 cm−3 is a key challenge for the full integration of Ge into silicon-based technology. Such a highly doped layer of both p- and n type is needed to provide ohmic contacts with low specific resistance. We have studied the effect of ion implantation parameters i.e., ion energy, fluence, ion type, and protective layer on the effective concentration of electrons. We have shown that the maximum electron concentration increases as the thickness of the doping layer decreases. The degradation of the implanted Ge surface can be minimized by performing ion implantation at temperatures that are below −100 °C with ion flux less than 60 nAcm−2 and maximum ion energy less than 120 keV. The implanted layers are flash-lamp annealed for 20 ms in order to inhibit the diffusion of the implanted ions during the recrystallization process.
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16
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Deng L, Li W, Li H, Cai W, Wang J, Zhang H, Jia H, Wang X, Cheng S. A Hierarchical Copper Oxide- Germanium Hybrid Film for High Areal Capacity Lithium Ion Batteries. Front Chem 2020; 7:869. [PMID: 31970147 PMCID: PMC6960130 DOI: 10.3389/fchem.2019.00869] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 12/03/2019] [Indexed: 11/13/2022] Open
Abstract
Self-supported electrodes represent a novel architecture for better performing lithium ion batteries. However, lower areal capacity restricts their commercial application. Here, we explore a facial strategy to increase the areal capacity without sacrificing the lithium storage performance. A hierarchical CuO–Ge hybrid film electrode will not only provide high areal capacity but also outstanding lithium storage performance for lithium ion battery anode. Benefiting from the favorable structural advance as well as the synergic effect of the Ge film and CuO NWs array, the hybrid electrode exhibits a high areal capacity up to 3.81 mA h cm−2, good cycling stability (a capacity retention of 90.5% after 150 cycles), and superior rate performance (77.4% capacity remains even when the current density increased to 10 times higher).
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Affiliation(s)
- Liying Deng
- College of Physics and Information Engineering, Institute of Micro-Nano Devices and Solar Cells, Fuzhou University, Fuzhou, China
| | - Wangyang Li
- College of Physics and Information Engineering, Institute of Micro-Nano Devices and Solar Cells, Fuzhou University, Fuzhou, China
| | - Hongnan Li
- College of Physics and Information Engineering, Institute of Micro-Nano Devices and Solar Cells, Fuzhou University, Fuzhou, China
| | - Weifan Cai
- NOVITAS, Nanoelectronics Centre of Excellence, School of Electrical and Electronics Engineering, Nanyang Technological University, Singapore, Singapore
| | - Jingyuan Wang
- NOVITAS, Nanoelectronics Centre of Excellence, School of Electrical and Electronics Engineering, Nanyang Technological University, Singapore, Singapore
| | - Hong Zhang
- College of Physics and Information Engineering, Institute of Micro-Nano Devices and Solar Cells, Fuzhou University, Fuzhou, China
| | - Hongjie Jia
- College of Physics and Information Engineering, Institute of Micro-Nano Devices and Solar Cells, Fuzhou University, Fuzhou, China
| | - Xinghui Wang
- College of Physics and Information Engineering, Institute of Micro-Nano Devices and Solar Cells, Fuzhou University, Fuzhou, China.,Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou, China
| | - Shuying Cheng
- College of Physics and Information Engineering, Institute of Micro-Nano Devices and Solar Cells, Fuzhou University, Fuzhou, China.,Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou, China
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Dixon-Luinenburg O, Celano U, Vandervorst W, Paredis K. Carrier profiling with fast Fourier transform scanning spreading resistance microscopy: A case study for Ge, GaAs, InGaAs, and InP. Ultramicroscopy 2019; 206:112809. [PMID: 31301608 DOI: 10.1016/j.ultramic.2019.06.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 06/13/2019] [Accepted: 06/27/2019] [Indexed: 11/28/2022]
Abstract
Quantitative scanning spreading resistance microscopy is currently a powerful method for carrier profiling in scaled nanoelectronic devices. Faced with the further reduction of dimensions and increasing architecture complexity, a force modulation method was developed to address the challenges associated with parasitic series resistances. Called fast Fourier transform scanning spreading resistance microscopy, the method has been shown to increase dynamic range when profiling Si devices and retains the doping contrast even in the presence of a series resistance. In this work we systematically investigate the potential of fast Fourier transform scanning spreading resistance microscopy for Ge, GaAs, InP, and InGaAs, presenting a quantitative comparison with Si as well as a more in-depth understanding of the capabilities and limitations of the method. Our results show that both GaAs and InP greatly benefit, with a significantly larger dynamic range and the ability to filter undesired series resistances. Doping concentration contrast in the presence of a series resistance can also be maintained in Ge but with high noise. For InGaAs there are only minor benefits. These findings prove that fast Fourier transform scanning spreading resistance microscopy is a valuable extension to regular scanning spreading resistance microscopy for more accurate carrier profiling in Si and non-Si materials, especially in architectures where parasitic series resistances are present.
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Affiliation(s)
| | | | - Wilfried Vandervorst
- imec, Kapeldreef 75, 3001 Heverlee, Belgium; Instituut voor Kern- en Stralingsfysica, KU Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium
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18
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Zhang D, Zhang Q, Li S, Yang H. Effects of Au and Ge Additions on the Microstructures and Properties of Ag-1.5Cu-0.1Y Alloys. Materials (Basel) 2019; 12:ma12010123. [PMID: 30609702 PMCID: PMC6337095 DOI: 10.3390/ma12010123] [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: 11/24/2018] [Revised: 12/22/2018] [Accepted: 12/26/2018] [Indexed: 06/09/2023]
Abstract
The application of silver is seriously affected by its tendency to oxidize and corrode. Therefore, the addition of proper alloying elements to silver-based alloys to achieve better properties has become a hot topic at present. In this current study, the effects of the addition of the two elements Au and Ge on the microstructures and properties of Ag-1.5Cu-0.1Y alloys were investigated. The results showed that the microstructures were refined and the second dendrite was shortened in the Ag-1.5Cu-0.1Y alloys with the addition of Au and Ge. Adding Au enhanced the corrosion resistance of the Ag-1.5Cu-0.1Y alloys. Furthermore, the corrosion resistance of the Ag-1.5Cu-0.1Y alloys with the addition of both Ge and Au was better than that of the alloy samples with Au added alone. The best corrosion resistance of the Ag-1.5Cu-0.1Y alloys was achieved by adding 1.0 wt.% Au and 1.0 wt.% Ge. The microhardness was enhanced by the addition of Au and Ge, and was strongly correlated with the secondary dendrite arm spacing (λ₂) of the Ag-1.5Cu-0.1Y alloys. In addition, the Au addition could improve the conductivity of the Ag-1.5Cu-0.1Y alloy; however, Ge had little effect on the conductivity of the alloy samples. This work provides an experimental basis for the design of better performing silver-based alloys.
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Affiliation(s)
- Desheng Zhang
- School of Metallurgy, Northeastern University, Shenyang 110819, China.
| | - Qin Zhang
- School of Metallurgy, Northeastern University, Shenyang 110819, China.
| | - Sida Li
- School of Metallurgy, Northeastern University, Shenyang 110819, China.
| | - Hongying Yang
- School of Metallurgy, Northeastern University, Shenyang 110819, China.
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19
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Levitt RN, Gourri E, Gassner C, Banez-Sese G, Salam A, Denomme GA, Yang E. Molecular characterization and multidisciplinary mana gement of Gerbich hemolytic disease of the newborn. Pediatr Blood Cancer 2018; 65:e27014. [PMID: 29469208 DOI: 10.1002/pbc.27014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 12/30/2017] [Accepted: 01/22/2018] [Indexed: 01/17/2023]
Abstract
Gerbich (Ge) antigens are high frequency red cell antigens expressed on glycophorin C (GYPC) and glycophorin D. Hemolytic disease of the fetus and newborn (HDFN) due to Gerbich antibody is rare and presents a clinical challenge, as Gerbich negative blood is scarce. We report a case of HDFN due to maternal Ge3 negative phenotype and anti-Ge3 alloimmunization, successfully managed by transfusion of maternal blood. Molecular testing revealed that the mother has homozygous deletion of exon 3 of GYPC, the father is homozygous wildtype for GYPC, and the infant is obligate heterozygote expressing Ge3.
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Affiliation(s)
- Rebecca N Levitt
- Department of Pediatrics, Inova Children's Hospital, Falls Church, Virginia
| | - Elise Gourri
- Blood Transfusion Service Zurich, Swiss Red Cross (SRC), Zürich-Schlieren, Switzerland
| | - Christoph Gassner
- Blood Transfusion Service Zurich, Swiss Red Cross (SRC), Zürich-Schlieren, Switzerland
| | - Grace Banez-Sese
- Inova Schar Cancer Institute Apheresis Service, Inova Blood Donor Services, Inova Donor Services, Sterling, Virginia
| | - Abdus Salam
- Blood Bank and Transfusion Service, Inova Fairfax Hospital, Falls Church, Virginia
| | - Gregory A Denomme
- Diagnostic laboratories, BloodCenter of Wisconsin, Milwaukee, Wisconsin
| | - Elizabeth Yang
- Department of Hematology-Oncology, Pediatric Specialists of Virginia, Falls Church, Virginia
- Department of Pediatrics, George Washington University School of Medicine, Washington, District of Columbia
- Virginia Commonwealth University School of Medicine-Inova Campus, Falls Church, Virginia
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20
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Filella M, Rodríguez-Murillo JC. Less-studied TCE: are their environmental concentrations increasing due to their use in new technologies? Chemosphere 2017; 182:605-616. [PMID: 28525874 DOI: 10.1016/j.chemosphere.2017.05.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 04/10/2017] [Accepted: 05/03/2017] [Indexed: 05/23/2023]
Abstract
The possible environmental impact of the recent increase in use of a group of technology-critical elements (Nb, Ta, Ga, In, Ge and Te) is analysed by reviewing published concentration profiles in environmental archives (ice cores, ombrotrophic peat bogs, freshwater sediments and moss surveys) and evaluating temporal trends in surface waters. No increase has so far been recorded. The low potential direct emissions of these elements, resulting from their absolute low production levels, make it unlikely that the increasing use of these elements in modern technology has any noticeable effect on their environmental concentrations on a global scale. This holds particularly true for those of these elements that are probably emitted in relatively high amounts from other human activities (i.e., coal combustion and non-ferrous smelting), such as In, the most studied element of the group.
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Affiliation(s)
- M Filella
- Institute F.-A. Forel, University of Geneva, Boulevard Carl-Vogt 66, CH-1205 Geneva, Switzerland.
| | - J C Rodríguez-Murillo
- Museo Nacional de Ciencias Naturales, CSIC, Serrano 115 dpdo., E-28006 Madrid, Spain
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21
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Yanagida Y, Oishi T, Miyaji T, Watanabe C, Nitta N. Nanoporous Structure Formation in GaSb, InSb, and Ge by Ion Beam Irradiation under Controlled Point Defect Creation Conditions. Nanomaterials (Basel) 2017; 7:E180. [PMID: 28696351 DOI: 10.3390/nano7070180] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 07/06/2017] [Accepted: 07/06/2017] [Indexed: 11/19/2022]
Abstract
Ion beam irradiation-induced nanoporous structure formation was investigated on GaSb, InSb, and Ge surfaces via controlled point defect creation using a focused ion beam (FIB). This paper compares the nanoporous structure formation under the same extent of point defect creation while changing the accelerating voltage and ion dose. Although the same number of point defects were created in each case, different structures were formed on the different surfaces. The depth direction density of the point defects was an important factor in this trend. The number of point defects required for nanoporous structure formation was 4 × 1022 vacancies/m2 at a depth of 18 nm under the surface, based on a comparison of similar nanoporous structure features in GaSb. The nanoporous structure formation by ion beam irradiation on GaSb, InSb, and Ge surfaces was controlled by the number and areal distribution of the created point defects.
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22
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Lee YW, Kim DM, Kim SJ, Kim MC, Choe HS, Lee KH, Sohn JI, Cha SN, Kim JM, Park KW. In Situ Synthesis and Characterization of Ge Embedded Electrospun Carbon Nanostructures as High Performance Anode Material for Lithium-Ion Batteries. ACS Appl Mater Interfaces 2016; 8:7022-7029. [PMID: 26895137 DOI: 10.1021/acsami.5b12284] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
While active materials based on germanium (Ge) are considered as a promising alternative anodic electrode due to their relatively high reversible capacity and excellent lithium-ion diffusivity, the quite unstable structural/electrochemical stability and severe volume expansion or pulverization problems of Ge electrodes remain a considerable challenge in lithium ion batteries (LIBs). Here, we present the development of Ge embedded in one-dimensional carbon nanostructures (Ge/CNs) synthesized by the modified in situ electrospinning technique using a mixed electrospun solution consisting of a Ge precursor as an active material source and polyacrylonitrile (PAN) as a carbon source. The as-prepared Ge/CNs exhibit superior lithium ion behavior properties, i.e., highly reversible specific capacity, rate performance, Li ion diffusion coefficient, and superior cyclic stability (capacity retention: 85% at 200 mA g(-1)) during Li alloying/dealloying processes. These properties are due to the high electrical conductivity and unique structures containing well-embedded Ge nanoparticles (NPs) and a one-dimensional carbon nanostructure as a buffer medium, which is related to the volume expansion of Ge NPs. Thus, it is expected that the Ge/CNs can be utilized as a promising alternative anodic material in LIBs.
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Affiliation(s)
- Young-Woo Lee
- Department of Engineering Science, University of Oxford , Oxford OX1 3PJ, United Kingdom
- Department of Chemical Engineering, Soongsil University , Seoul 156-743, Republic of Korea
| | - Da-Mi Kim
- Department of Chemical Engineering, Soongsil University , Seoul 156-743, Republic of Korea
| | - Si-Jin Kim
- Department of Chemical Engineering, Soongsil University , Seoul 156-743, Republic of Korea
| | - Min-Cheol Kim
- Department of Chemical Engineering, Soongsil University , Seoul 156-743, Republic of Korea
| | - Hui-Seon Choe
- Department of Chemical Engineering, Soongsil University , Seoul 156-743, Republic of Korea
| | - Kyu-Ho Lee
- Department of Chemical Engineering, Soongsil University , Seoul 156-743, Republic of Korea
| | - Jung Inn Sohn
- Department of Engineering Science, University of Oxford , Oxford OX1 3PJ, United Kingdom
| | - Seung Nam Cha
- Department of Engineering Science, University of Oxford , Oxford OX1 3PJ, United Kingdom
| | - Jong Min Kim
- Department of Engineering Science, University of Oxford , Oxford OX1 3PJ, United Kingdom
| | - Kyung-Won Park
- Department of Chemical Engineering, Soongsil University , Seoul 156-743, Republic of Korea
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23
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Paradis H, de Vismes Ott A, Luo M, Cagnat X, Piquemal F, Gurriaran R. Low level measurement of (60)Co by gamma ray spectrometry using γ-γ coincidence. Appl Radiat Isot 2015; 109:487-492. [PMID: 26682892 DOI: 10.1016/j.apradiso.2015.11.075] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 11/24/2015] [Indexed: 11/18/2022]
Abstract
This paper presents the latest development of the laboratory to measure the natural and artificial massic activities in environmental samples. The measurement method of coincident emitters by gamma-gamma coincidence using an anti-Compton device and its digital electronics is described. Results obtained with environmental samples are shown. Despite its low efficiency, this method decreases detection limits of (60)Co for certain samples compared to conventional gamma-ray spectrometry due to its very low background.
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Affiliation(s)
- H Paradis
- Laboratoire de Mesure de la Radioactivité dans l'Environnement, IRSN, Orsay, France.
| | - A de Vismes Ott
- Laboratoire de Mesure de la Radioactivité dans l'Environnement, IRSN, Orsay, France
| | - M Luo
- Laboratoire de Mesure de la Radioactivité dans l'Environnement, IRSN, Orsay, France
| | - X Cagnat
- Laboratoire de Mesure de la Radioactivité dans l'Environnement, IRSN, Orsay, France
| | - F Piquemal
- Centre Etudes Nucléaires de Bordeaux Gradignan, CNRS/IN2P3, Gradignan, France; LSM, Laboratoire Souterrain de Modane, Modane, France
| | - R Gurriaran
- Laboratoire de Mesure de la Radioactivité dans l'Environnement, IRSN, Orsay, France
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24
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Jin S, Yang G, Song H, Cui H, Wang C. Ultrathin Hexagonal 2D Co₂ GeO₄ Nanosheets: Excellent Li-Storage Performance and ex Situ Investigation of Electrochemical Mechanism. ACS Appl Mater Interfaces 2015; 7:24932-24943. [PMID: 26486013 DOI: 10.1021/acsami.5b08446] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Two-dimensional (2D) nanostructures are a desirable configuration for lithium ion battery (LIB) electrodes due to their large open surface and short pathway for lithium ions. Therefore, exploring new anode materials with 2D structure could be a promising direction to develop high-performance LIBs. Herein, we synthesized a new type of 2D Ge-based double metal oxides for lithium storage. Ultrathin hexagonal Co2GeO4 nanosheets with nanochannels are prepared by a simple hydrothermal method. When used as LIB anode, the sample delivers excellent cyclability and rate capability. A highly stable capacity of 1026 mAhg(-1) was recorded after 150 cycles. Detailed morphology and phase evolutions were detected by TEM and EELS measurements. It is found that Co2GeO4 decomposed into Ge NPs which are evenly dispersed in amorphous Co/Li2O matrix during the cycling process. Interestingly, the in situ formed Co matrix could serve as a conductive network for electrochemical process of Ge. Moreover, aggregations of Ge NPs could be restricted by the ultrathin configuration and Co/Li2O skeleton, leading to unique structure stability. Hence, the large surface areas, ultrathin thickness, and atomically metal matrix finally bring the superior electrochemical performance.
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Affiliation(s)
- Shuaixing Jin
- The Key Laboratory of Low-Carbon Chemistry & Energy Conservation of Guangdong Province, ‡State Key Laboratory of Optoelectronic Materials and Technologies, and §School of Physics Science and Engineering, Sun Yat-sen (Zhongshan) University , Guangzhou 510275, People's Republic of China
| | - Gongzheng Yang
- The Key Laboratory of Low-Carbon Chemistry & Energy Conservation of Guangdong Province, ‡State Key Laboratory of Optoelectronic Materials and Technologies, and §School of Physics Science and Engineering, Sun Yat-sen (Zhongshan) University , Guangzhou 510275, People's Republic of China
| | - Huawei Song
- The Key Laboratory of Low-Carbon Chemistry & Energy Conservation of Guangdong Province, ‡State Key Laboratory of Optoelectronic Materials and Technologies, and §School of Physics Science and Engineering, Sun Yat-sen (Zhongshan) University , Guangzhou 510275, People's Republic of China
| | - Hao Cui
- The Key Laboratory of Low-Carbon Chemistry & Energy Conservation of Guangdong Province, ‡State Key Laboratory of Optoelectronic Materials and Technologies, and §School of Physics Science and Engineering, Sun Yat-sen (Zhongshan) University , Guangzhou 510275, People's Republic of China
| | - Chengxin Wang
- The Key Laboratory of Low-Carbon Chemistry & Energy Conservation of Guangdong Province, ‡State Key Laboratory of Optoelectronic Materials and Technologies, and §School of Physics Science and Engineering, Sun Yat-sen (Zhongshan) University , Guangzhou 510275, People's Republic of China
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25
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Abstract
Knowledge of nanoscale heteroepitaxy is continually evolving as advances in material synthesis reveal new mechanisms that have not been theoretically predicted and are different than what is known about planar structures. In addition to a wide range of potential applications, core/shell nanowire structures offer a useful template to investigate heteroepitaxy at the atomistic scale. We show that the growth of a Ge shell on a Si core can be tuned from the theoretically predicted island growth mode to a conformal, crystalline, and smooth shell by careful adjustment of growth parameters in a narrow growth window that has not been explored before. In the latter growth mode, Ge adatoms preferentially nucleate islands on the {113} facets of the Si core, which outgrow over the {220} facets. Islands on the low-energy {111} facets appear to have a nucleation delay compared to the {113} islands; however, they eventually coalesce to form a crystalline conformal shell. Synthesis of epitaxial and conformal Si/Ge/Si core/multishell structures enables us to fabricate unique cylindrical ring nanowire field-effect transistors, which we demonstrate to have steeper on/off characteristics than conventional core/shell nanowire transistors.
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Affiliation(s)
- Binh-Minh Nguyen
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
- Department of Electrical and Computer Engineering, University of California San Diego , La Jolla, California 92093, United States
| | - Brian Swartzentruber
- Center for Integrated Nanotechnologies, Sandia National Laboratories , Albuquerque, New Mexico 87185, United States
| | - Yun Goo Ro
- Department of Electrical and Computer Engineering, University of California San Diego , La Jolla, California 92093, United States
| | - Shadi A Dayeh
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
- Department of Electrical and Computer Engineering, University of California San Diego , La Jolla, California 92093, United States
- Materials Science Program, University of California San Diego , La Jolla, California 92093, United States
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26
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Zhang L, Li H, Guo Y, Tang K, Woicik J, Robertson J, McIntyre PC. Selective Passivation of GeO2/Ge Interface Defects in Atomic Layer Deposited High-k MOS Structures. ACS Appl Mater Interfaces 2015; 7:20499-20506. [PMID: 26334784 DOI: 10.1021/acsami.5b06087] [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: 06/05/2023]
Abstract
Effective passivation of interface defects in high-k metal oxide/Ge gate stacks is a longstanding goal of research on germanium metal-oxide-semiconductor devices. In this paper, we use photoelectron spectroscopy to probe the formation of a GeO2 interface layer between an atomic layer deposited Al2O3 gate dielectric and a Ge(100) substrate during forming gas anneal (FGA). Capacitance- and conductance-voltage data were used to extract the interface trap density energy distribution. These results show selective passivation of interface traps with energies in the top half of the Ge band gap under annealing conditions that produce GeO2 interface layer growth. First-principles modeling of Ge/GeO2 and Ge/GeO/GeO2 structures and calculations of the resulting partial density of states (PDOS) are in good agreement with the experiment results.
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Affiliation(s)
| | - Huanglong Li
- Engineering Department, Cambridge University , Cambridge CB2 1PZ, United Kingdom
- Department of Precision Instrument, Tsinghua University , Beijing, China
| | - Yuzheng Guo
- Engineering Department, Cambridge University , Cambridge CB2 1PZ, United Kingdom
| | | | - Joseph Woicik
- Materials Science and Engineering Laboratory, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
| | - John Robertson
- Engineering Department, Cambridge University , Cambridge CB2 1PZ, United Kingdom
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27
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Wang X, Susantyoko RA, Fan Y, Sun L, Xiao Q, Zhang Q. Vertically aligned CNT-supported thick Ge films as high-performance 3D anodes for lithium ion batteries. Small 2014; 10:2826-2742. [PMID: 24700811 DOI: 10.1002/smll.201400003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 02/05/2014] [Indexed: 06/03/2023]
Abstract
The electrochemical performance of a thick Ge film (ca. 1020 nm) is dramatically improved by adopting vertically aligned carbon nanotube (VACNT) arrays as a 3D current collector. The VACNT-supported thick Ge film exhibits high reversible specific capacity (1352 mAh g(-1) ), and excellent capacity retention (97.2% after 100 cycles) and rate capability (843 mAh g(-1) at 10 C).
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Affiliation(s)
- Xinghui Wang
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
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28
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Marzegalli A, Isa F, Groiss H, Müller E, Falub CV, Taboada AG, Niedermann P, Isella G, Schäffler F, Montalenti F, von Känel H, Miglio L. Unexpected dominance of vertical dislocations in high-misfit ge/si(001) films and their elimination by deep substrate patterning. Adv Mater 2013; 25:4408-4412. [PMID: 23788016 DOI: 10.1002/adma.201300550] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 04/11/2013] [Indexed: 06/02/2023]
Abstract
An innovative strategy in dislocation analysis, based on comparison between continuous and tessellated film, demonstrates that vertical dislocations, extending straight up to the surface, easily dominate in thick Ge layers on Si(001) substrates. The complete elimination of dislocations is achieved by growing self-aligned and self-limited Ge microcrystals with fully faceted growth fronts, as demonstrated by AFM extensive etch-pit counts.
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Affiliation(s)
- Anna Marzegalli
- L-NESS and Dept. of Materials Science, Università degli Studi di Milano-Bicocca, via Cozzi 53, Milan, Italy.
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29
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Jeon YL, Park TS, Cho SY, Oh SH, Kim MH, Kang SY, Lee WI. The first Korean case report of anti- Gerbich. Ann Lab Med 2012; 32:442-4. [PMID: 23130346 PMCID: PMC3486941 DOI: 10.3343/alm.2012.32.6.442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 06/05/2012] [Accepted: 07/24/2012] [Indexed: 11/25/2022] Open
Abstract
In this study, we report the first Korean case of an anti-Gerbich (Ge) alloantibody to a high-incidence antigen that belongs to the Ge blood group system. The alloantibody was detected in a middle-aged Korean woman who did not have a history of transfusion. Her blood type was B+, and findings from the antibody screening test revealed 1+ reactivity in all panels except the autocontrol. The cross-matching test showed incompatible results with all 5 packed red blood cells. Additional blood type antigen and antibody tests confirmed the anti-Ge alloantibody. While rare, cases of hemolytic transfusion reaction or hemolytic disease in newborns due to anti-Ge have been recently reported in the literature. Therefore, additional further studies on alloantibodies to high-incidence antigens, including anti-Ge, are necessary in the future.
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Affiliation(s)
- You La Jeon
- Department of Medicine, Kyung Hee University Graduate School Seoul, Korea
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30
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Shah VA, Myronov M, Wongwanitwatana C, Bawden L, Prest MJ, Richardson-Bullock JS, Rhead S, Parker EHC, Whall TE, Leadley DR. Electrical isolation of dislocations in Ge layers on Si(001) substrates through CMOS-compatible suspended structures. Sci Technol Adv Mater 2012; 13:055002. [PMID: 27877523 PMCID: PMC5099624 DOI: 10.1088/1468-6996/13/5/055002] [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] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2012] [Accepted: 10/21/2012] [Indexed: 06/06/2023]
Abstract
Suspended crystalline Ge semiconductor structures are created on a Si(001) substrate by a combination of epitaxial growth and simple patterning from the front surface using anisotropic underetching. Geometric definition of the surface Ge layer gives access to a range of crystalline planes that have different etch resistance. The structures are aligned to avoid etch-resistive planes in making the suspended regions and to take advantage of these planes to retain the underlying Si to support the structures. The technique is demonstrated by forming suspended microwires, spiderwebs and van der Pauw cross structures. We finally report on the low-temperature electrical isolation of the undoped Ge layers. This novel isolation method increases the Ge resistivity to 280 Ω cm at 10 K, over two orders of magnitude above that of a bulk Ge on Si(001) layer, by removing material containing the underlying misfit dislocation network that otherwise provides the main source of electrical conduction.
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31
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Abstract
The use of ultraviolet photoemission to determine the density of valence and conduction states is reviewed. Two approaches are recognized. In one, the photoemission as well as other studies are used to locate experimentally a limited number of features of the band structure. Once these are fixed, band structure calculations could be carried out throughout the zone and checked against other features of the photoemission data. If the agreement is sufficiently good, the density of states is then calculated from the band structure. The second method depends only on experimental data. Using this approach, features of the density of states are determined directly by the photoemission experiment without recourse to band calculations. In cases where bands are wide and k clearly provides an empirically important optical selection rule, this is possible only for portions of the bands which are relatively flat. Successful determinations of this type are cited for PbTe, and GaAs. In metals with narrow d bands such as Cu, it has been found empirically that one may explain fairly well the experimental energy distribution curves in terms of transitions between a density of initial and final states (the optical density of states, ODS) requiring only conservation of energy. The ODS determined by such ultraviolet photoemission studies have more strong detailed structure than the density of states determined by any other experimental method. Studies on a large number of materials indicate that the position in energy of this structure correlates rather well with the position in energy of structure in the calculated density of states. It is suggested, following the very recent theoretical work of Doniach, that k conservation becomes less important (and nondirect transitions more important) as the mass of the hole becomes larger. This is due to the change in k of electrons in states near the Fermi level as they attempt to screen the hole left in the optical excitation process. These electrons take up the excess momentum. One would expect the k conservation selection rule to play an increasingly important role as the mass of the hole decreases. This is in agreement with experiment.
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Affiliation(s)
- W E Spicer
- Stanford Electronic Laboratory, Stanford University, Stanford, California 94305
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