550 results on '"Sputter deposition"'
Search Results
2. Sputter-deposited TiOx thin film as a buried interface modification layer for efficient and stable perovskite solar cells
- Author
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Jiang, Xiongzhuo, Zeng, Jie, Sun, Kun, Li, Zerui, Xu, Zhuijun, Pan, Guangjiu, Guo, Renjun, Liang, Suzhe, Bulut, Yusuf, Sochor, Benedikt, Schwartzkopf, Matthias, Reck, Kristian A., Strunskus, Thomas, Faupel, Franz, Roth, Stephan V., Xu, Baomin, and Müller-Buschbaum, Peter
- Published
- 2024
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3. Combinatorial processing and evaluation of the phase evolution and oxidation behavior of Hf-Al-Si refractory complex concentrated alloys
- Author
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Cooper, Sophia R., Ghoshal, Anindya, Murugan, Muthuvel, Blair, Victoria L., Aouadi, Samir M., Voevodin, Andrey A., and Young, Marcus L.
- Published
- 2024
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4. Electron scattering at interfaces in Ru(0001)/Co(0001) multilayers.
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Shen, Poyen, Lavoie, Christian, and Gall, Daniel
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ELECTRON scattering , *SPUTTER deposition , *X-ray diffraction , *MULTILAYERS , *ALLOYS - Abstract
Electron transport measurements on 60-nm-thick multilayers containing N = 2–58 individual Ru and Co layers are employed to quantify the specific resistance of Ru/Co interfaces. Sputter deposition on Al2O3(0001) at Ts = 400 °C leads to a 0001 preferred orientation with x-ray diffraction (XRD) Ru and Co 0002 peaks that shift closer to each other with increasing N, suggesting interfacial intermixing. The intermixing is quantified by x-ray reflectivity (XRR) and confirmed by an XRD Ru/Co alloy peak that develops during in situ synchrotron annealing as well as for deposition at a higher Ts = 600 °C. The room-temperature resistivity increases from 15.0 to 47.5 μΩ cm with decreasing superlattice period Λ = 60–2 nm. This is attributed to increasing electron scattering at the intermixed metal interfaces. The transport data are well described by a parallel conductor model that treats metal layers and the intermixed alloy as parallel resistors, where the resistivity of the intermixed alloy of 60.4 μΩ cm is determined from a co-deposited Ru/Co sample. Data fitting provides values for the effective thickness of the intermixed interface of 16.8 nm, in good agreement with the XRR value, yielding a Ru/Co contact resistance of 8.5 × 10−15 Ω m2 for interfaces deposited at 400 °C. The overall results show that the Ru/Co contact resistance is dominated by a high-resistivity interfacial alloy and, therefore, is a strong function of the deposition process, particularly the processing temperature. [ABSTRACT FROM AUTHOR]
- Published
- 2025
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5. Electrothermal enhancement of β-(AlxGa1−x)2O3/Ga2O3 heterostructure field-effect transistors via back-end-of-line sputter-deposited AlN layer.
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Lundh, James Spencer, Cress, Cory, Jacobs, Alan G., Cheng, Zhe, Masten, Hannah N., Spencer, Joseph A., Sasaki, Kohei, Gallagher, James, Koehler, Andrew D., Konishi, Keita, Graham, Samuel, Kuramata, Akito, Anderson, Travis J., Tadjer, Marko J., Hobart, Karl D., and Mastro, Michael A.
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SPUTTER deposition , *FIELD-effect transistors , *THERMAL conductivity , *REACTIVE sputtering , *ELECTRIC fields - Abstract
The electrothermal device performance of β-(Al0.21Ga0.79)2O3/Ga2O3 heterostructure field-effect transistors (HFETs) was enhanced by incorporating a 400 nm thick AlN capping layer via back-end-of-line room-temperature reactive sputter deposition. The AlN-capped HFETs demonstrated DC power densities >5 W/mm, higher than any previous report on lateral β-Ga2O3 transistors on native substrates. The breakdown voltage (VB) of the uncapped HFETs was 569 ± 250 V with a maximum VB of 947 V. For the AlN-capped HFETs, VB increased to 1210 ± 351 V with a maximum VB of 1868 V. The AlN-capped HFETs demonstrated a 27% reduction in device-level thermal resistance (RTH) as measured from the gate electrode. The combined use of electrical and thermal simulation helped elucidate the coupled electrothermal contributions to the measured reduction in the temperature rise for the AlN-capped HFETs. Although the measured AlN film thermal conductivity (13.3 ± 1.3 W/mK) was comparable to that of bulk β-Ga2O3, the capping layer still reduced the simulated peak channel temperature rise by ∼4% due to heat spreading only. Electrical simulation revealed that electric field spreading was an additional mechanism that contributed to the majority of the simulated 18% reduction in the peak channel temperature rise through delocalization and redistribution of the heat generation in the channel. Thermal modeling was used to evaluate further improvements in thermal performance that can be realized by optimizing the sputter deposition process to achieve thicker and higher thermal conductivity AlN. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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6. Effect of physical vapor deposition on contacts to 2D MoS2.
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Saifur Rahman, M., Agyapong, Ama D., and Mohney, Suzanne E.
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PHYSICAL vapor deposition , *SPUTTER deposition , *SEMICONDUCTOR junctions , *COPPER , *FIELD-effect transistors - Abstract
Two-dimensional (2D) molybdenum disulfide (MoS2) holds immense promise for next-generation electronic applications. However, the role of contact deposition at the metal/semiconductor interface remains a critical factor influencing device performance. This study investigates the impact of different metal deposition techniques, specifically electron-beam evaporation and sputtering, for depositing Cu, Pd, Bi, Sn, Pt, and In. Utilizing Raman spectroscopy with backside illumination, we observe changes at the buried metal/1L MoS2 interface after metal deposition. Sputter deposition causes more damage to monolayer MoS2 than electron-beam evaporation, as indicated by partial or complete disappearance of first-order E′(Γ)α and A′1(Γ)α Raman modes post-deposition. We correlated the degree of damage from sputtered atoms to the cohesive energies of the sputtered material. Through fabrication and testing of field-effect transistors, we demonstrate that electron-beam evaporated Sn/Au contacts exhibit superior performance including reduced contact resistance (~12×), enhanced mobility (~4.3×), and lower subthreshold slope (~0.6×) compared to their sputtered counterparts. Our findings underscore the importance of contact fabrication methods for optimizing the performance of 2D MoS2 devices and the value of Raman spectroscopy with backside illumination for gaining insight into contact performance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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7. Effect of physical vapor deposition on contacts to 2D MoS2.
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Saifur Rahman, M., Agyapong, Ama D., and Mohney, Suzanne E.
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PHYSICAL vapor deposition ,SPUTTER deposition ,SEMICONDUCTOR junctions ,COPPER ,FIELD-effect transistors - Abstract
Two-dimensional (2D) molybdenum disulfide (MoS
2 ) holds immense promise for next-generation electronic applications. However, the role of contact deposition at the metal/semiconductor interface remains a critical factor influencing device performance. This study investigates the impact of different metal deposition techniques, specifically electron-beam evaporation and sputtering, for depositing Cu, Pd, Bi, Sn, Pt, and In. Utilizing Raman spectroscopy with backside illumination, we observe changes at the buried metal/1L MoS2 interface after metal deposition. Sputter deposition causes more damage to monolayer MoS2 than electron-beam evaporation, as indicated by partial or complete disappearance of first-order E′(Γ)α and A′1 (Γ)α Raman modes post-deposition. We correlated the degree of damage from sputtered atoms to the cohesive energies of the sputtered material. Through fabrication and testing of field-effect transistors, we demonstrate that electron-beam evaporated Sn/Au contacts exhibit superior performance including reduced contact resistance (~12×), enhanced mobility (~4.3×), and lower subthreshold slope (~0.6×) compared to their sputtered counterparts. Our findings underscore the importance of contact fabrication methods for optimizing the performance of 2D MoS2 devices and the value of Raman spectroscopy with backside illumination for gaining insight into contact performance. [ABSTRACT FROM AUTHOR]- Published
- 2024
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- View/download PDF
8. Interfacial defect reduction enhances universal power law response in Mo–SiNx granular metals.
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McGarry, Michael P., Gilbert, Simeon J., Yates, Luke, Meyerson, Melissa L., Kotula, Paul G., Bachman, William B., Sharma, Peter A., Flicker, Jack D., Siegal, Michael P., and Biedermann, Laura B.
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PHOTOELECTRON spectroscopy , *PRECIOUS metals , *METAL nanoparticles , *SPUTTER deposition , *ELECTRON traps , *ELECTRON transport - Abstract
Granular metals (GMs), consisting of metal nanoparticles separated by an insulating matrix, frequently serve as a platform for fundamental electron transport studies. However, few technologically mature devices incorporating GMs have been realized, in large part because intrinsic defects (e.g., electron trapping sites and metal/insulator interfacial defects) frequently impede electron transport, particularly in GMs that do not contain noble metals. Here, we demonstrate that such defects can be minimized in molybdenum–silicon nitride (Mo–SiNx) GMs via optimization of the sputter deposition atmosphere. For Mo–SiNx GMs deposited in a mixed Ar/N2 environment, x-ray photoemission spectroscopy shows a 40%–60% reduction of interfacial Mo-silicide defects compared to Mo–SiNx GMs sputtered in a pure Ar environment. Electron transport measurements confirm the reduced defect density; the dc conductivity improved (decreased) by 104–105 and the activation energy for variable-range hopping increased 10×. Since GMs are disordered materials, the GM nanostructure should, theoretically, support a universal power law (UPL) response; in practice, that response is generally overwhelmed by resistive (defective) transport. Here, the defect-minimized Mo–SiNx GMs display a superlinear UPL response, which we quantify as the ratio of the conductivity at 1 MHz to that at dc, Δ σ ω. Remarkably, these GMs display a Δ σ ω up to 107, a three-orders-of-magnitude improved response than previously reported for GMs. By enabling high-performance electric transport with a non-noble metal GM, this work represents an important step toward both new fundamental UPL research and scalable, mature GM device applications. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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9. Bond formation at polycarbonate | X interfaces (X = Ti, Al, TiAl) probed by X-ray photoelectron spectroscopy and density functional theory molecular dynamics simulations
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Patterer, Lena, Ondračka, Pavel, Bogdanovski, Dimitri, Jende, Leonie, Prünte, Stephan, Mráz, Stanislav, Karimi Aghda, Soheil, Stelzer, Bastian, Momma, Markus, and Schneider, Jochen M.
- Published
- 2022
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10. Heteroepitaxial growth of Ga2O3 thin films on Al2O3(0001) by ion beam sputter deposition.
- Author
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Kalanov, Dmitry, Gerlach, Jürgen W., Bundesmann, Carsten, Bauer, Jens, Lotnyk, Andriy, von Wenckstern, Holger, Anders, André, and Unutulmazsoy, Yeliz
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THIN films , *SPUTTER deposition , *ION beams , *SEMICONDUCTOR films , *PHYSICAL vapor deposition - Abstract
Deposition of epitaxial oxide semiconductor films using physical vapor deposition methods requires a detailed understanding of the role of energetic particles to control and optimize the film properties. In the present study, Ga 2 O 3 thin films are heteroepitaxially grown on Al 2 O 3 (0001) substrates using oxygen ion beam sputter deposition. The influence of the following relevant process parameters on the properties of the thin films is investigated: substrate temperature, oxygen background pressure, energy of primary ions, ion beam current, and sputtering geometry. The kinetic energy distributions of ions in the film-forming flux are measured using an energy-selective mass spectrometer, and the resulting films are characterized regarding crystalline structure, microstructure, surface roughness, mass density, and growth rate. The energetic impact of film-forming particles on the thin film structure is analyzed, and a noticeable decrease in crystalline quality is observed above the average energy of film-forming Ga + ions around 40 eV for the films grown at a substrate temperature of 725 ° C. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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11. Influence of oxygen pressure on the ferroelectricity of pulsed laser deposition fabricated epitaxial Y-doped HfO2.
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Huang, Jia-hao, Yang, Lei, Wei, Lu-qi, Wang, Tao, Fan, Wen-cheng, Qu, Ke, Guan, Zhao, Chen, Bin-bin, Xiang, Ping-hua, Duan, Chun-gang, and Zhong, Ni
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PULSED laser deposition , *ATOMIC layer deposition , *FERROELECTRICITY , *FERROELECTRIC materials , *SPUTTER deposition , *PULSED lasers - Abstract
Ferroelectric properties of hafnium-based thin films have gained significant interest, yet the fundamental mechanisms responsible for the emergence of the ferroelectric phase continue to be inadequately investigated. In contrast with polycrystalline films fabricated by atomic layer deposition or sputter methods, which possess uncertainty in polarization orientation, epitaxial ferroelectric HfO2-based materials are less investigated, especially for factors such as electric field and oxygen vacancy, which are proposed and examined for their potential impacts on phase stability. In this study, Y-doped hafnium oxide (HYO) ferroelectric epitaxial films were fabricated using pulsed laser deposition, with variations in oxygen pressure during the deposition process. Structural and electrical analyses of HYO epitaxial ferroelectric films prepared under differing oxygen pressures revealed a correlation between the ferroelectric properties of the films and the oxygen content. An optimal selection of oxygen pressure was found to be conducive to the formation of HYO epitaxial ferroelectric films, presenting a promising avenue for future ferroelectric memory applications. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
12. Influence of oxygen pressure on the ferroelectricity of pulsed laser deposition fabricated epitaxial Y-doped HfO2.
- Author
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Huang, Jia-hao, Yang, Lei, Wei, Lu-qi, Wang, Tao, Fan, Wen-cheng, Qu, Ke, Guan, Zhao, Chen, Bin-bin, Xiang, Ping-hua, Duan, Chun-gang, and Zhong, Ni
- Subjects
PULSED laser deposition ,ATOMIC layer deposition ,FERROELECTRICITY ,FERROELECTRIC materials ,SPUTTER deposition ,PULSED lasers - Abstract
Ferroelectric properties of hafnium-based thin films have gained significant interest, yet the fundamental mechanisms responsible for the emergence of the ferroelectric phase continue to be inadequately investigated. In contrast with polycrystalline films fabricated by atomic layer deposition or sputter methods, which possess uncertainty in polarization orientation, epitaxial ferroelectric HfO
2 -based materials are less investigated, especially for factors such as electric field and oxygen vacancy, which are proposed and examined for their potential impacts on phase stability. In this study, Y-doped hafnium oxide (HYO) ferroelectric epitaxial films were fabricated using pulsed laser deposition, with variations in oxygen pressure during the deposition process. Structural and electrical analyses of HYO epitaxial ferroelectric films prepared under differing oxygen pressures revealed a correlation between the ferroelectric properties of the films and the oxygen content. An optimal selection of oxygen pressure was found to be conducive to the formation of HYO epitaxial ferroelectric films, presenting a promising avenue for future ferroelectric memory applications. [ABSTRACT FROM AUTHOR]- Published
- 2024
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- View/download PDF
13. Wafer-scale development, characterization, and high temperature stabilization of epitaxial Cr2O3 films grown on Ru(0001).
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Cumston, Quintin, Patrick, Matthew, Hegazy, Ahmed R., Zangiabadi, Amirali, Daughtry, Maximillian, Coffey, Kevin R., Barmak, Katayun, and Kaden, William E.
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CHROMIUM oxide , *HIGH temperatures , *SPUTTER deposition , *TRANSMISSION electron microscopy , *LATTICE constants - Abstract
This work outlines conditions suitable for the heteroepitaxial growth of Cr2O3(0001) films (1.5–20 nm thick) on a Ru(0001)-terminated substrate. Optimized growth is achieved by sputter deposition of Cr within a 4 mTorr Ar/O2 20% ambient at Ru temperatures ranging from 450 to 600 °C. The Cr2O3 film adopts a 30° rotated honeycomb configuration with respect to the underlying Ru(0001) substrate and exhibits a hexagonal lattice parameter consistent with that for bulk Cr2O3(0001). Heating to 700 °C within the same environment during film preparation leads to Ru oxidation. Exposure to temperatures at or above 400 °C in a vacuum, Ar, or Ar/H2 3% leads to chromia film degradation characterized by increased Ru 3d XPS intensity coupled with concomitant Cr 2p and O 1s peak attenuations when compared to data collected from unannealed films. An ill-defined but hexagonally well-ordered RuxCryOz surface structure is noted after heating the film in this manner. Heating within a wet Ar/H2 3% environment preserves the Cr2O3(0001)/Ru(0001) heterolayer structure to temperatures of at least 950 °C. Heating an Ru–Cr2O3–Ru heterostacked film to 950 °C within this environment is shown by cross-sectional scanning/transmission electron microscopy (S/TEM) to provide clear evidence of retained epitaxial bicrystalline oxide interlayer structure, interlayer immiscibility, and epitaxial registry between the top and bottom Ru layers. Subtle effects marked by O enrichment and O 1s and Cr 2p shifts to increased binding energies are noted by XPS in the near-Ru regions of Cr2O3(0001)/Ru(0001) and Ru(0001)/Cr2O3(0001)/Ru(0001) films after annealing to different temperatures in different sets of environmental conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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14. Low temperature sputtering deposition of Al1−xScxN thin films: Physical, chemical, and piezoelectric properties evolution by tuning the nitrogen flux in (Ar + N2) reactive atmosphere.
- Author
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Signore, M. A., Serra, A., Manno, D., Quarta, G., Calcagnile, L., Maruccio, L., Sciurti, E., Melissano, E., Campa, A., Martucci, M. C., Francioso, L., and Velardi, L.
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PIEZOELECTRIC thin films , *THIN film deposition , *SPUTTER deposition , *LOW temperatures , *KELVIN probe force microscopy , *RUTHERFORD backscattering spectrometry , *ATMOSPHERIC nitrogen - Abstract
This work investigates the physical properties of Al1−xScxN thin films sputtered at low temperatures by varying the process conditions. Specifically, the films were deposited at room temperature by applying a radio frequency power equal to 150 W to an AlSc alloy (60:40) target, varying the nitrogen flux percentage in the (Ar + N2) sputtering atmosphere (30%, 40%, 50%, and 60%) and keeping constant the working pressure at 5 × 10−3 mbar. The structural and chemical properties of the Al1−xScxN films were studied by x-ray diffraction and Rutherford backscattering spectrometry techniques, respectively. The piezoelectric response was investigated by piezoresponse force microscopy. In addition, the surface potential was evaluated for the first time for Sc-doped AlN thin films by Kelvin probe force microscopy, providing piezoelectric coefficients free from the no-piezoelectric additional effect to the mechanical deformation, i.e., the electrostatic force. By alloying AlN with scandium, the piezoelectric response was strongly enhanced (up to 200% compared to undoped AlN), despite the low deposition temperature and the absence of any other additional energy source supplied to the adatoms during thin film growth, which generally promotes a better structural arrangement of polycrystalline film. This is a strategic result in the field of microelectromechanical systems completely fabricated at low temperatures. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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15. Deposition of ultrathick heavy-metal alloys on rotating substrates by high-power impulse magnetron sputtering: Target erosion effects.
- Author
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Shin, S. J., Bae, J. H., Engwall, A. M., Bayu Aji, L. B., Baker, A. A., Taylor, G. V., Merlo, J. B., Sohngen, L. R., Moody, J. D., and Kucheyev, S. O.
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MAGNETRON sputtering , *EROSION , *SPUTTER deposition , *PLASMA diagnostics , *ALLOYS , *ELECTRICAL resistivity - Abstract
Sputter deposition of ultrathick (≈ 20 μ m) Au–Ta alloy coatings on sphero-cylindrical substrates is key for the fabrication of hohlraums for magnetically assisted inertial confinement fusion. Here, we study the deposition of AuTa 4 alloy coatings onto rotating substrates. We use high-power impulse magnetron sputtering (HiPIMS) in a constant peak target voltage mode. Results show that the target erosion state has a strong impact on the dominant crystallographic phase, microstructure, surface morphology, and electrical resistivity of AuTa 4 films. This is due to effects of changes in the confining magnetic field with target erosion on the HiPIMS discharge characteristics and the sputter source output. We quantify these effects via plasma diagnostics and discuss the optimization of HiPIMS deposition of ultrathick films for cases when target erosion effects dominate film properties. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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16. CeO2:ZnO hybrid nanorods for self-powered UV-photodetectors.
- Author
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Banari, Mohammad, Memarian, Nafiseh, Kumar, Pankaj, You, Shujie, Vomiero, Alberto, and Concina, Isabella
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CERIUM oxides , *COPPER , *SPUTTER deposition , *BAND gaps , *MATERIALS testing - Abstract
In this study we present and discuss p-n heterostructures for photodetection. The hybrid structures consist of CeO 2 :ZnO-Cu 2 O, featuring different concentrations of CeO 2 , fabricated by using hydrothermal co-growth for CeO 2 and ZnO, and sputtering deposition for Cu 2 O. As the concentration of CeO 2 in the ZnO pristine nanorods was increased, the structural, optical and functional features of the materials showed relevant changes, in terms of crystalline domains and optical bandgap. After Cu 2 O deposition, the ternary materials were tested as UV photodectors, showing very good performance in terms of fast response and decay times. Specifically, we found that the CeO 2 :ZnO-Cu 2 O devices maintain a stable current under light irradiation, whose value was dependent on the CeO 2 amount incorporated in the ZnO 1D nanostructures. Among all tested configurations, the 5.5 % hybrid CeO 2 :ZnO-Cu 2 O exhibits the highest current efficiency, accompanied by rapid rise and decay times. Our investigation suggests that the CeO 2 :ZnO-Cu 2 O configuration holds great potential for optoelectronic applications, particularly in the development of UV photodetectors. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
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17. Mechanical and corrosion resistance properties of in-situ formed ZrN/ZrO2 composite coatings.
- Author
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Zong, Sifan, Hong, Zhihao, Meng, Fantao, Huang, Zhangyi, Wang, Haomin, and Wang, Long
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FUSION reactor blankets , *COMPOSITE coating , *ELECTROLYTIC corrosion , *SPUTTER deposition , *CORROSION resistance - Abstract
A novel ZrN/ZrO 2 corrosion-resistant composite coating was fabricated by radiofrequency (RF) magnetron sputtering method. The effects of sputtering power and deposition temperature on the microstructure, mechanical property and corrosion resistance of ZrN/ZrO 2 composite coatings were examined through X-ray diffraction, scanning electron microscopy, nanoindentation and electrochemical impedance spectroscopy. The results indicate that the crystallinity of the ZrN/ZrO 2 composite coating increases with the increase of sputtering power and deposition temperature, becoming smoother and denser and behaving a better mechanical property. Moreover, the corrosion resistance of the coating has been significantly increased under the deposition parameters of a sputtering power of 300 W and a deposition temperature of 300 °C. The electrochemical corrosion test reveals a corrosion rate for the coating of 1.39 × 10−4 mm/yr, which is 5.5 times lower than that of the 316L substrate, and a charge transfer resistance of 4.37 × 106 Ω cm2, which is 11.5 times higher than that of the 316L substrate. The effects of phase structure, crystallinity, coating defects, and residual stress on the mechanical properties and electrochemical corrosion resistance were discussed in details. Our study provides a new insight into produce corrosion-resistant coatings for structural materials used in fusion reactor tritium breeding blanket, where the corrosion of lithium compound still be a thorny issue. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
18. Phase selectivity upon flash-lamp annealing of sputter deposited amorphous titanium oxide films.
- Author
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Gago, R., Prucnal, S., Azpeitia, J., Jiménez, I., and Álvarez-Fraga, L.
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TITANIUM dioxide films , *TITANIUM oxides , *SPUTTER deposition , *REACTIVE sputtering , *TITANIUM dioxide , *X-ray absorption near edge structure , *MAGNETRON sputtering , *RUTILE - Abstract
We report the impact of flash-lamp-annealing (FLA) on the structural evolution of amorphous titania (TiO 2) films produced by DC reactive magnetron sputtering. TiO 2 films were grown at room-temperature at different oxygen partial pressure (P O2) and subsequently annealed as a function of the FLA energy density. X-ray diffraction confirms that FLA induces phase formation from the initial amorphous state with a general transition from anatase to rutile by increasing the FLA energy density (temperature). Interestingly, the transformation onset of anatase to rutile is achieved at lower energy densities for higher P O2. On the contrary, films with a highly resilient anatase phase can be produced at relatively low P O2. A detailed analysis of the pristine amorphous structure carried out by X-ray absorption near-edge structure indicates the role of oxygen sites in the observed phase transformation. In particular, oxygen vacancies seem to stabilize the anatase phase at high temperatures. The results show the relevance of subtle changes in the initial amorphous structure for phase selectivity in TiO 2 films upon FLA. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
19. Fine-Tuning Cathode Performance: The Influence of Argon Deposition Pressure on LiMn 2 O 4 Thin Film Electrochemistry for Li-Ion Batteries.
- Author
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Ambriz-Vargas, Fabián, Garza-Hernández, Raquel, Martínez-Flores, José Salvador, Aguirre-Tostado, Francisco Servando, Martínez-Guerra, Eduardo, and Quevedo-López, Manuel
- Subjects
LITHIUM manganese oxide ,SPUTTER deposition ,THIN films ,ELECTROLYTIC reduction ,CHARGE transfer - Abstract
Lithium manganese oxide (LiMn
2 O4 ) is an effective cathode material for high-capacity lithium-ion (Li-ion) batteries. Therefore, to optimize battery efficiency, it is essential to understand how sputtering deposition conditions affect the quality and performance of LiMn2 O4 . This research examines how argon deposition pressure affects the stoichiometric characteristics and electrochemical performance of LiMn2 O4 . The study finds that changing argon deposition pressures, from a low of 5 mTorr to a high of 30 mTorr, results in the formation of different coating stoichiometries. At low argon deposition pressures, stoichiometric LiMn2 O4 cathode coatings formed, exhibiting the highest discharge capacity of 115 mAh/g. Conversely, at high argon deposition pressures, non-stoichiometric LiMn2 O4 with lithium deficiency was produced. These coatings exhibited diminished electrochemical behavior, achieving a discharge capacity of only 70 mAh/g at 5 mTorr. The lack of lithium resulted in a significant reduction in electrochemical performance, indicated by a high surface charge transfer resistance (R2 = 48,529 Ω), which led to a low discharge capacity of 40 mAh/g. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
20. High-quality GaN thin film deposition at low temperature by ECR plasma-assisted sputter deposition method and its dependence of sapphire substrate misorientation angle.
- Author
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Torii, Hironori and Matsui, Shinsuke
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CYCLOTRON resonance ,THIN film deposition ,GALLIUM nitride ,SUBSTRATES (Materials science) ,SPUTTER deposition ,MAGNETRON sputtering - Abstract
Gallium nitride (GaN) thin films were deposited by electron cyclotron resonance (ECR) plasma-assisted sputtering, which combines GaN-magnetron sputtering with argon and nitrogen plasma assistance using an ECR high-density plasma. GaN films on the misorientation-angle-0.0° (just) sapphire substrate showed very good crystallinity with a GaN(0002) rocking curve (XRC) full width at half maximum (FWHM) of 0.042° and epitaxial growth confirmed by φ-scan measurements at a low heating temperature of 350 °C. However, the GaN thin film had a rough surface with circular grains about 100 nm in diameter and a surface root-mean-square height (Sq) of 1.21 nm. Therefore, the misorientation angle of the sapphire substrate was varied from 0.2° to 10.0°. As a result, the grains observed on the just substrate disappeared at 0.5°. The film had Sq: 0.33 nm, and the FWHM of the XRC of GaN(0002) was 0.066°, indicating improved surface flatness while maintaining crystallinity. This is considered to be due to the step flow, which promotes ECR plasma-assisted diffusion on the terrace even at the low temperature of 350 °C. The polarity of the GaN thin film was analyzed by time-of-flight atomic scattering surface analysis and found to be N-polar on all substrates. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. Effects of deposition angle on the thin film quality of indium tin oxide grown by single beam ion source-assisted magnetron sputtering.
- Author
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Amollo, Tabitha A., Wang, Keliang, Zhen, Bocong, Johnson, Tyler, and Fan, Qi Hua
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ELECTRICAL engineering materials ,THIN film deposition ,SPUTTER deposition ,INDIUM tin oxide ,THIN films ,MAGNETRON sputtering - Abstract
This work proves that the sputtering deposition angle has significant effects on the ITO film crystallinity and properties under the assistance of an ion beam at room temperature. The films grown at 30º and 45º are crystalline while the ones produced at 60º and 90º are amorphous in nature. The films' sheet resistance was observed to be lower at 30º and 45º than at 60 and 90º. The films produced at 60º exhibited the highest optical peak transmittance ca. 90% followed by those grown at 45º ca. 84% in the visible region. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
22. Low‐Temperature Synthesis of Stable CaZn2P2 Zintl Phosphide Thin Films as Candidate Top Absorbers.
- Author
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Quadir, Shaham, Yuan, Zhenkun, Esparza, Guillermo L., Dugu, Sita, Mangum, John S., Pike, Andrew, Hasan, Muhammad Rubaiat, Kassa, Gideon, Wang, Xiaoxin, Coban, Yagmur, Liu, Jifeng, Kovnir, Kirill, Fenning, David P., Reid, Obadiah G., Zakutayev, Andriy, Hautier, Geoffroy, and Bauers, Sage R.
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OPTICAL films , *SPUTTER deposition , *THIN films , *SOLAR cells , *PHOTOELECTROCHEMICAL cells , *OPTICAL conductivity , *OPTOELECTRONIC devices - Abstract
The development of tandem photovoltaics and photoelectrochemical solar cells requires new absorber materials with bandgaps in the range of ≈1.5–2.3 eV, for use in the top cell paired with a narrower‐gap bottom cell. An outstanding challenge is finding materials with suitable optoelectronic and defect properties, good operational stability, and synthesis conditions that preserve underlying device layers. This study demonstrates the Zintl phosphide compound CaZn2P2 as a compelling candidate semiconductor for these applications. Phase‐pure, ≈500 nm‐thick CaZn2P2 thin films are prepared using a scalable reactive sputter deposition process at growth temperatures as low as 100 °C, which is desirable for device integration. Ultraviolet‐visible spectroscopy shows that CaZn2P2 films exhibit an optical absorptivity of ≈104 cm−1 at ≈1.95 eV direct bandgap. Room‐temperature photoluminescence (PL) measurements show near‐band‐edge optical emission, and time‐resolved microwave conductivity (TRMC) measurements indicate a photoexcited carrier lifetime of ≈30 ns. CaZn2P2 is highly stable in both ambient conditions and moisture, as evidenced by PL and TRMC measurements. Experimental data are supported by first‐principles calculations, which indicate the absence of low‐formation‐energy, deep intrinsic defects. Overall, this study shall motivate future work integrating this potential top cell absorber material into tandem solar cells. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. Enhancing Thermoelectrical Properties of Silver-Nanowire-Embedded Heatable Textiles via Sputter-Mediated Nanowire Structural Modulation.
- Author
-
Lee, Chankyoung, Park, Jaewoo, and Choi, Dooho
- Subjects
- *
METALLIC wire , *SPUTTER deposition , *TEXTILE technology , *POLYESTERS , *SILVER - Abstract
This study addresses the fabrication of flexible, heatable fabrics via the integration of globally interconnected silver nanowires (Ag NWs) with sputter-deposited silver atoms. Conventional heatable fabrics, which utilize macroscale or nanoscale conductive wires, often face challenges in balancing flexibility, comfort, and structural durability. The proposed method leverages the advantages of nanoscale metallic wires and vacuum-based sputtering, maintaining fabric flexibility while enhancing heating efficiency. The fabrication process involves dip-coating polyester fabric with Ag NWs, followed by sputter deposition to modulate the nanowire morphology, thereby improving key electrical properties such as wire resistance and contact resistance between wires. The experimental results demonstrate that sputter-deposited Ag NW fabrics exhibit significantly enhanced heating capability compared to undeposited, otherwise identical counterparts. Further, the fabrics maintain their heating characteristics under repeated mechanical bending and prolonged electrical stress, highlighting their potential for use in wearable electronic applications. This approach offers a promising solution to the limitations of current heatable textile technologies, providing a pathway for the development of comfortable, efficient, and durable heatable fabrics. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. Heavy Ge Doping in GaN via Pulsed Sputtering to Tailor the Optical Bandgap Energy.
- Author
-
Naito, Aiko, Ueno, Kohei, and Fujioka, Hiroshi
- Subjects
- *
CARRIER density , *SPUTTER deposition , *EPITAXY , *ELECTRON mobility , *OPTOELECTRONIC devices - Abstract
The epitaxial growth of heavily Ge‐doped GaN films using pulsed sputtering deposition (PSD) on AlN (0001)/sapphire substrates is presented and the correlations among their structural, electrical, and optical properties are investigated. High‐quality Ge‐doped PSD‐GaN films are grown with electron concentrations of 0.33–4.4 × 1020 cm−3. Notably, cathode luminescence spectra reveal the absence of defect‐induced emissions associated with Ga vacancies (2.3–2.4 eV), consistent with the high electron mobilities of the films. As the electron concentration increases, the optical bandgap also increases. This correlation can be explained by combining the theoretical formulas for the Burstein–Moss shift and the bandgap renormalization effects. Remarkably, the optical bandgap reaches 3.84 eV at 4.4 × 1020 cm−3 carrier concentration, marking the highest value reported for the optical bandgap of GaN. These results indicate the potential of heavy Ge doping in GaN via PSD for applications in highly transparent conductive layers and tunneling junctions within GaN‐based optoelectronic devices. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. Temperature‐Dependent Characteristics of AlN/Al0.5Ga0.5N High Electron Mobility Transistors with Highly Degenerate n‐Type GaN Regrown Ohmic Contacts.
- Author
-
Maeda, Ryota, Ueno, Kohei, Kobayashi, Atsushi, and Fujioka, Hiroshi
- Subjects
- *
MODULATION-doped field-effect transistors , *SPUTTER deposition , *FERMI level , *RADIO frequency , *ACTIVATION energy , *ELECTRON gas - Abstract
Herein, the temperature‐dependent characteristics of AlN/Al0.5Ga0.5N high electron mobility transistors (HEMTs) with highly degenerate n‐type GaN (d‐GaN) ohmic contacts fabricated via pulsed sputtering deposition (PSD) are investigated. The ohmic contacts formed at the source and drain regions demonstrate low resistivity within the temperature range of 77–473 K. It is found that the temperature dependence of the contact resistance (RC) for the AlN/Al0.5Ga0.5N HEMTs with regrowth d‐GaN contacts is attributable to the energy barrier induced by the Fermi level difference between the d‐GaN contacts and Al0.5Ga0.5N channel layer. Notably, the RC between the d‐GaN contacts and the channel layer is 1.4 and 0.15 Ω mm at 77 and 473 K, respectively. Temperature‐dependent device on‐resistance coincides with the temperature variation of the two‐dimensional electron gas sheet resistance because the contact resistance is negligibly low in the studied temperature range. Moreover, AlN/Al0.5Ga0.5N HEMTs with d‐GaN contacts exhibit excellent switching characteristics, achieving an ION/IOFF ratio of ≈106, even at high temperatures up to 473 K. The results indicate that the PSD d‐GaN contact technique has potential to overcome the limitations of ohmic contacts for high Al‐composition AlGaN electronic devices, especially for next‐generation high‐power‐density radio frequency transistors operating at high temperatures. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Prediction by a hybrid machine learning model for high-mobility amorphous In2O3: Sn films fabricated by RF plasma sputtering deposition using a nitrogen-mediated amorphization method.
- Author
-
Kamataki, Kunihiro, Ohtomo, Hirohi, Itagaki, Naho, Lesly, Chawarambawa Fadzai, Yamashita, Daisuke, Okumura, Takamasa, Yamashita, Naoto, Koga, Kazunori, and Shiratani, Masaharu
- Subjects
- *
MACHINE learning , *SPUTTER deposition , *RADIOFREQUENCY sputtering , *THIN film deposition , *MAGNETRONS , *PLASMA deposition , *RADIO frequency - Abstract
In this study, we developed a hybrid machine learning technique by combining appropriate classification and regression models to address challenges in producing high-mobility amorphous In2O3:Sn (a-ITO) films, which were fabricated by radio-frequency magnetron sputtering with a nitrogen-mediated amorphization method. To overcome this challenge, this hybrid model that was consisted of a support vector machine as a classification model and a gradient boosting regression tree as a regression model predicted the boundary conditions of crystallinity and experimental conditions with high mobility for a-ITO films. Based on this model, we were able to identify the boundary conditions between amorphous and crystalline crystallinity and thin film deposition conditions that resulted in a-ITO films with 27% higher mobility near the boundary than previous research results. Thus, this prediction model identified key parameters and optimal sputtering conditions necessary for producing high-mobility a-ITO films. The identification of such boundary conditions through machine learning is crucial in the exploration of thin film properties and enables the development of high-throughput experimental designs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
27. Evaluating the cradle-to-gate environmental impact and cooling performance of advanced daytime radiative cooling materials to establish a comparative framework for a novel photonic meta-concrete
- Author
-
N. Adams, L. Carlosena, and K. Allacker
- Subjects
Environmental impact assessment ,Thin film deposition techniques ,Sputter deposition ,Radiative cooling materials assessment ,Heat transfer model ,Environmental sciences ,GE1-350 ,Environmental law ,K3581-3598 - Abstract
Abstract Background By the end of 2050, it is expected that 68% of the population will live in urban areas. A higher density of people living in cities generates an increased urban heat island. Radiative cooling (RC) materials are proposed as a key strategy to mitigate global warming and urban heating. The Horizon 2020 project MIRACLE aims at developing a new RC material based on conventional concrete. This paper presents a framework developed for comparing both the cradle-to-gate environmental impact and cooling potential of the newly developed photonic meta-concrete (or any other new RC material) with existing RC materials. The framework is applied to various RC materials using the generic Ecoinvent v3.6 database. The impact assessment method is in line with the Belgian life cycle assessment method for buildings and covers the 15 environmental impact categories of the EN15804:A2. The cooling performance is assessed by implementing the material spectral emissivity into a thermal model for Brussels and Madrid. Results The study shows that the sputtering process contributes over 75% to the cradle-to-gate environmental impact of several RC materials, while materials produced without this process, have significantly lower impacts. The assessment of the cooling potential showed that convection heat gains make it difficult to create an all-year round cooling material. The comparison with a conventional building material, a concrete roof tile, hence shows great potential for these RC materials as heating gains during summer are significantly reduced. Analysing cooling performance alongside environmental impact, the study identified two RC materials, i.e. D6 and D10, as the most preferred in both Brussels and Madrid, considering their lower environmental impact and superior performance. Conclusions The literature review revealed that a standardised way to assess and benchmark RC materials based on their cradle-to-gate environmental impact and cooling performance is lacking to date. This paper hence presents, for the first time, a method to compare RC materials considering these two characteristics. This method allows to identify the most competitive RC materials, which will serve in our study to benchmark the newly developed photonic meta-concrete.
- Published
- 2024
- Full Text
- View/download PDF
28. Magnetron Sputtering as a Solvent-Free Method for Fabrication of Nanoporous ZnO Thin Films for Highly Efficient Photocatalytic Organic Pollution Degradation
- Author
-
Kamila Ćwik, Jakub Zawadzki, Rafał Zybała, Monika Ożga, Bartłomiej Witkowski, Piotr Wojnar, Małgorzata Wolska-Pietkiewicz, Maria Jędrzejewska, Janusz Lewiński, and Michał A. Borysiewicz
- Subjects
ZnO nanostructures ,photocatalysis ,photoluminescence ,solvent-less ,sputter deposition ,Physics ,QC1-999 ,Physical and theoretical chemistry ,QD450-801 - Abstract
Zinc oxide (ZnO) is one of the most versatile semiconductor materials with many potential applications. Understanding the interactions between the surface chemistry of ZnO along with its physico-chemical properties are essential for the development of ZnO as a robust photocatalyst for the removal of aqueous pollutants. We report on the fabrication of nanoparticle-like porous ZnO films and the correlation between the fabrication process parameters, particle size, surface oxygen vacancies (SOV), photoluminescence and photocatalytic performance. The synthesis route is unique, as highly porous zinc layers with nanoscale grains were first grown via magnetron sputtering, a vacuum-based technique, and subsequently annealed at temperatures of 400 °C, 600 °C and 800 °C in oxygen flow to oxidise them to zinc oxide (ZnO) while maintaining their porosity. Our results show that as the annealing temperature increases, nanoparticle agglomeration increases, and thus there is a decrease in the active sites for the photocatalytic reaction. However, for selected samples the annealing leads to an increase of the photocatalytic efficiency, which we explain based on the analysis of defects in the material, based on photoluminescence (PL). PL analysis showed that in the material the transition between the conduction band and the oxygen vacancy is responsible for the green emission centered at 525 nm, but the photocatalytic activity correlated best with surface states—related emission.
- Published
- 2024
- Full Text
- View/download PDF
29. Bond Formation at Polycarbonate | X Interfaces (X = Al2O3, TiO2, TiAlO2) Studied by Theory and Experiments.
- Author
-
Patterer, Lena, Ondračka, Pavel, Bogdanovski, Dimitri, Mráz, Stanislav, Pöllmann, Peter J., Karimi Aghda, Soheil, Vašina, Petr, and Schneider, Jochen M.
- Subjects
SPUTTER deposition ,PHOTOELECTRON spectroscopy ,THIN film deposition ,MOLECULAR dynamics ,DENSITY functional theory - Abstract
Interfacial bond formation during sputter deposition of metal‐oxide thin films onto polycarbonate (PC) is investigated by ab initio molecular dynamics simulations and X‐ray photoelectron spectroscopy (XPS) analysis of PC|X interfaces (X = Al2O3, TiO2, TiAlO2). Generally, the predicted bond formation is consistent with the experimental data. For all three interfaces, the majority of bonds identified by XPS are (C─O)─metal bonds, whereas C─metal bonds are the minority. Compared to the PC|Al2O3 interface, the PC|TiO2 and PC|TiAlO2 interfaces exhibit a reduction in the measured interfacial bond density by 75 and ∼65%, respectively. Multiplying the predicted bond strength with the corresponding experimentally determined interfacial bond density shows that Al2O3 exhibits the strongest interface with PC, while TiO2 and TiAlO2 exhibit ∼70 and ∼60% weaker interfaces, respectively. This can be understood by considering the complex interplay between the metal‐oxide composition, the bond strength, and the population of bonds formed across the interface. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Numerical Study of Sputter Deposited Ultra-Low Loaded Effective Platinum Electrocatalyst Utilization in Proton Exchange Membrane Fuel Cell.
- Author
-
Kumar, Chidambaram Ramesh, Kanna, Parthasarathy Rajesh, Boopalan, Vignesh, Jose, Jobel, Arumugam, Senthil Kumar, Taler, Dawid, Sobota, Tomasz, and Taler, Jan
- Subjects
- *
PROTON exchange membrane fuel cells , *SPUTTER deposition , *COMPUTATIONAL fluid dynamics , *CATALYST supports , *CATALYTIC activity - Abstract
AbstractHigh Platinum loading levels in fuel cells may ensure better durability and catalytic activity but increases fuel cells’ cost, thereby hindering large-scale commercialization. The use of non-precious catalysts may seem like a lucrative solution, but they cannot substitute platinum completely. Hence, the focus should also be given to alternate fabrication methods of the catalyst layer that will achieve ultra-low platinum loadings. Some of the methods are modified thin film method, electrodeposition, sputter deposition method, dual ion beam assisted deposition, and electroless deposition. Nano carbons as catalyst support can also be given priority as they aid the catalyst with mechanical properties. Each method is compared, reflecting the inherent advantages and disadvantages. Finally, the sputter deposition method was chosen as the most promising method in the current state of technology and research. A computational fluid dynamics simulation of a fuel cell using the sputter deposition method was performed which showed high power utilization thereby validating the benefits of the method. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Evaluating the cradle-to-gate environmental impact and cooling performance of advanced daytime radiative cooling materials to establish a comparative framework for a novel photonic meta-concrete.
- Author
-
Adams, N., Carlosena, L., and Allacker, K.
- Subjects
THIN film deposition ,HEAT radiation & absorption ,URBAN heat islands ,HEAT convection ,ENVIRONMENTAL impact analysis - Abstract
Background: By the end of 2050, it is expected that 68% of the population will live in urban areas. A higher density of people living in cities generates an increased urban heat island. Radiative cooling (RC) materials are proposed as a key strategy to mitigate global warming and urban heating. The Horizon 2020 project MIRACLE aims at developing a new RC material based on conventional concrete. This paper presents a framework developed for comparing both the cradle-to-gate environmental impact and cooling potential of the newly developed photonic meta-concrete (or any other new RC material) with existing RC materials. The framework is applied to various RC materials using the generic Ecoinvent v3.6 database. The impact assessment method is in line with the Belgian life cycle assessment method for buildings and covers the 15 environmental impact categories of the EN15804:A2. The cooling performance is assessed by implementing the material spectral emissivity into a thermal model for Brussels and Madrid. Results: The study shows that the sputtering process contributes over 75% to the cradle-to-gate environmental impact of several RC materials, while materials produced without this process, have significantly lower impacts. The assessment of the cooling potential showed that convection heat gains make it difficult to create an all-year round cooling material. The comparison with a conventional building material, a concrete roof tile, hence shows great potential for these RC materials as heating gains during summer are significantly reduced. Analysing cooling performance alongside environmental impact, the study identified two RC materials, i.e. D6 and D10, as the most preferred in both Brussels and Madrid, considering their lower environmental impact and superior performance. Conclusions: The literature review revealed that a standardised way to assess and benchmark RC materials based on their cradle-to-gate environmental impact and cooling performance is lacking to date. This paper hence presents, for the first time, a method to compare RC materials considering these two characteristics. This method allows to identify the most competitive RC materials, which will serve in our study to benchmark the newly developed photonic meta-concrete. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. Alternative during‐growth chlorination of sputtered CdTe films and their implementation as activating layers in CdS/CdTe solar cells.
- Author
-
Calderón‐Martínez, Abraham Israel, Jiménez‐Sandoval, Omar, Rodríguez‐Melgarejo, Francisco, Hernández‐Landaverde, Martín Adelaido, Flores‐Ruiz, Francisco Javier, and Jiménez‐Sandoval, Sergio Joaquín
- Subjects
THIN film deposition ,SOLAR cells ,SOLAR technology ,CADMIUM telluride ,SPUTTER deposition ,CHLORINE - Abstract
Cadmium telluride is an efficient light absorbing material successfully used in solar cell technology. The efficiency of such photovoltaic devices is strongly dependent on post‐deposition thermal treatments in the presence of chlorine. The benefits of this process on the absorbing layer include removal of intragrain defects, grain growth enhancement, and grain boundaries passivation. The absorber chlorination is a crucial step for which CdCl2 is the most common choice. Its use, however, has been overshadowed by the toxicity of Cd‐ and Cl‐containing vapors and residues. In this work, chlorine was incorporated in CdTe films during growth using sputtering targets with different chloride compounds: CdCl2, TeCl4, BaCl2, CaCl2, or LiCl. After characterizing these films, CdTe:CdCl2 and CdTe:TeCl4 were selected as feasible absorbers for testing their performance in photovoltaic devices. Efficiencies near 7% were obtained in as‐grown unoptimized cells in which the absorber consisted of two layers: pristine CdTe and CdTe:CdCl2 or CdTe:TeCl4. The chlorinated layers acted as Cl sources for the adjacent CdTe and CdS, which produced a homogeneous distribution of chlorine throughout the cell. In the during‐growth activating‐layer (DG‐AL) method used here, the chlorine diffusion during growth had a doping effect, passivated grain boundaries and defects, improved the back contact characteristics by reducing the CdTe work function, and lowered the pinhole formation probability by producing a compact chlorinated CdTe layer. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
33. Influence of chemistry and topography on the wettability of copper.
- Author
-
Marie Lößlein, Sarah, Merz, Rolf, Rodríguez-Martínez, Yerila, Schäfer, Florian, Grützmacher, Philipp G., Horwat, David, Kopnarski, Michael, and Mücklich, Frank
- Subjects
- *
WETTING , *SURFACE chemistry , *TOPOGRAPHY , *SURFACE topography , *COPPER , *COPPER surfaces , *SPUTTER deposition , *COPPER oxide - Abstract
[Display omitted] To understand the complex interplay of topography and surface chemistry in wetting, fundamental studies investigating both parameters are needed. Due to the sensitivity of wetting to miniscule changes in one of the parameters it is imperative to precisely control the experimental approach. A profound understanding of their influence on wetting facilitates a tailored design of surfaces with unique functionality. We present a multi-step study: The influence of surface chemistry is analyzed by determining the adsorption of volatile carbonous species (A) and by sputter deposition of metallic copper and copper oxides on flat copper substrates (B). A precise surface topography is created by laser processing. Isotropic topography is created by ps laser processing (C), and hierarchical anisotropic line patterns are produced by direct laser interference patterning (DLIP) with different pulse durations (D). Our results reveal that the long-term wetting response of polished copper surfaces stabilizes with time despite ongoing accumulation of hydrocarbons and is dominated by this adsorption layer over the oxide state of the substrate (Cu, CuO, Cu 2 O). The surfaces' wetting response can be precisely tuned by tailoring the topography via laser processing. The sub-pattern morphology of primary line-like patterns showed great impact on the static contact angle, wetting anisotropy, and water adhesion. An increased roughness inside the pattern valleys combined with a minor roughness on pattern peaks favors air-inclusions, isotropic hydrophobicity, and low water adhesion. Increasing depth of the primary topography can also induce air-inclusions despite increasing peak roughness while time dependent wetting transitions were observed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Magnetron Sputtering as a Solvent-Free Method for Fabrication of Nanoporous ZnO Thin Films for Highly Efficient Photocatalytic Organic Pollution Degradation.
- Author
-
Ćwik, Kamila, Zawadzki, Jakub, Zybała, Rafał, Ożga, Monika, Witkowski, Bartłomiej, Wojnar, Piotr, Wolska-Pietkiewicz, Małgorzata, Jędrzejewska, Maria, Lewiński, Janusz, and Borysiewicz, Michał A.
- Subjects
SURFACE chemistry ,SPUTTER deposition ,MAGNETRON sputtering ,THIN films ,SEMICONDUCTOR materials ,ZINC oxide films - Abstract
Zinc oxide (ZnO) is one of the most versatile semiconductor materials with many potential applications. Understanding the interactions between the surface chemistry of ZnO along with its physico-chemical properties are essential for the development of ZnO as a robust photocatalyst for the removal of aqueous pollutants. We report on the fabrication of nanoparticle-like porous ZnO films and the correlation between the fabrication process parameters, particle size, surface oxygen vacancies (SOV), photoluminescence and photocatalytic performance. The synthesis route is unique, as highly porous zinc layers with nanoscale grains were first grown via magnetron sputtering, a vacuum-based technique, and subsequently annealed at temperatures of 400 °C, 600 °C and 800 °C in oxygen flow to oxidise them to zinc oxide (ZnO) while maintaining their porosity. Our results show that as the annealing temperature increases, nanoparticle agglomeration increases, and thus there is a decrease in the active sites for the photocatalytic reaction. However, for selected samples the annealing leads to an increase of the photocatalytic efficiency, which we explain based on the analysis of defects in the material, based on photoluminescence (PL). PL analysis showed that in the material the transition between the conduction band and the oxygen vacancy is responsible for the green emission centered at 525 nm, but the photocatalytic activity correlated best with surface states—related emission. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. Morphological Stability Limits of Ag–Cu–Al Nanocrystalline Thin Films Prepared via Reactive Sputtering in Ar–O2 Mixed Gas.
- Author
-
Ueshima, Yoshiyuki, Hasegawa, Masakatsu, Kubota, Naoyoshi, Matamura, Yuya, Matsubara, Eiichiro, Seki, Kazuaki, and Hirato, Tetsuji
- Subjects
THIN films ,KIRKENDALL effect ,REACTIVE sputtering ,SPUTTER deposition ,CRYSTAL grain boundaries - Abstract
As a first step toward developing a downsized and high-performance O
2 separator suitable for large-scale industrial applications, such as steelmaking, we have studied nanocrystalline Ag alloy thin films with high O2 permeability via rapid diffusion at Ag grain boundaries, operating at plant-waste heat temperatures (200 °C to 500 °C). In the present study, fabrication of nanocrystalline Ag–2at. pctCu–10at. pctAl alloy thin films with Ag grain size below 10 nm was attempted via reactive sputtering in Ar–O2 using grain boundary pinning force of a large number of alumina particles. Cross-sectional observation of the fabricated thin film showed that the Ag grain size ranged from 4 to 15 nm when the film thickness was less than 200 nm, but when the film thickness exceeded 200 nm, the Ag grains abruptly coarsened, reaching a maximum grain size of 214 nm. Furthermore, large surface irregularities with sizes of up to 500 to 600 nm (equivalent to 2/3 of the film thickness) were also observed. Heat transfer analysis revealed that the Ag film partially melted because of the large amount of heat released by the oxidation of Al during sputtering deposition. The conditions necessary for the fabrication of high-Al nanocrystalline Ag alloy thin films via reactive sputtering in Ar–O2 gas without film melting were clarified. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
36. Effect of plasma discharge pulse length for GaN film crystallinity on sapphire substrate by high density convergent plasma sputtering device.
- Author
-
Misono, Itsuki, Motomura, Taisei, Tabaru, Tatsuo, Uehara, Masato, and Okuyama, Tetsuya
- Subjects
PLASMA flow ,SPUTTER deposition ,SUBSTRATES (Materials science) ,DIFFRACTION patterns ,PLASMA density - Abstract
Plasma discharge pulse length (t
PLength ) was investigated for its impact on the crystallinity of GaN films deposited on a sapphire substrate using a high-density convergent plasma sputtering device (CPSD). The study covered tPLength values from 1 to 200 ms, maintaining the substrate temperature at 200 °C. GaN films showed preferential orientation along the (0002) plane for all tPLength settings. X-ray diffraction analysis revealed a heteroepitaxial-like growth pattern with a sixfold symmetric diffraction pattern corresponding to GaN{10−10} planes. At a tPLength of 200 ms, the full width at half maximum of the rocking curve at GaN (0002) diffraction angle decreased to 1.6°. Optimizing the deposition rate per plasma discharge pulse with CPSD indicated the importance of selecting an optimal tPLength for achieving desirable crystalline properties in GaN film sputtering deposition. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
37. Magnetic contrast layers with functional SiO2 coatings for soft‐matter studies with polarized neutron reflectometry.
- Author
-
Dikaia, Olga, Luchini, Alessandra, Nylander, Tommy, Grunin, Alexei, Vorobiev, Alexei, and Goikhman, Alexandr
- Subjects
- *
NEUTRON reflectometry , *SILICON oxide films , *ATOMIC force microscopy , *SUBSTRATES (Materials science) , *SPUTTER deposition - Abstract
This study introduces silicon substrates with a switchable magnetic contrast layer (MCL) for polarized neutron reflectometry (PNR) experiments at the solid–liquid interface to study soft‐matter surface layers. During standard neutron reflectometry (NR) experiments on soft‐matter samples, structural and compositional information is obtained by collecting experimental data with different isotopic contrasts on the same sample. This approach is normally referred to as contrast matching, and it can be achieved by using solvents with different isotopic contrast, e.g. different H2O/D2O ratios, and/or by selective deuteration of the molecules. However, some soft‐matter systems might be perturbed by this approach, or it might be difficult to implement, particularly in the case of biological samples. In these scenarios, solid substrates with an MCL are an appealing alternative, as the magnetic contrast with the substrate can be used for partial recovery of information on the sample structure. More specifically, in this study, a magnetically soft Fe layer coated with SiO2 was produced by ion‐beam sputter deposition on silicon substrates of different sizes. The structure was evaluated using X‐ray reflectometry, atomic force microscopy, vibrating sample magnetometry and PNR. The collected data showed the high quality and repeatability of the MCL parameters, regardless of the substrate size or the thickness of the capping SiO2 layer. Previously proposed substrates with an iron MCL used an Au capping layer. The SiO2 capping layer proposed here allows reproduction of the typical surface of a standard silicon substrate used for NR experiments and is compatible with a large variety of soft‐matter samples. This application is demonstrated with ready‐to‐use 50 × 50 × 10 mm substrates in PNR experiments for the characterization of a lipid bilayer in a single solvent contrast. Overall, the article highlights the potential of PNR with an MCL for the investigation of soft‐matter samples. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. Enhanced solid solubility in hcp Co(Mo) nanoparticles formed via inert gas condensation.
- Author
-
Dhapola, S. and Shield, J. E.
- Subjects
- *
NANOPARTICLE size , *MAGNETIC anisotropy , *ANISOTROPIC crystals , *SPUTTER deposition , *TRANSMISSION electron microscopy - Abstract
Co–Mo alloy clusters with extended solubility of Mo in hcp Co were produced by inert gas condensation (IGC). While the equilibrium solubility of Mo in hexagonal close-packed (hcp) Co is on the order of 1 atomic percent, the non-equilibrium aspects of IGC resulted in ~ 18 atomic percent Mo dissolved in hcp Co. The extended solid solutions and hcp structure were observed across all of the processing conditions, which included variation of sputtering power and aperture size. There was, however, variation of nanoparticle size and magnetic behavior with processing parameters. The Co(Mo) nanoparticles were ferromagnetic at room temperature. Coercivities of the nanoparticles produced with a 2.5-mm aperture were independent of sputtering power and significantly higher than those of the nanoparticles produced with a 7-mm aperture. The coercivities of the nanoparticles produced with a 7-mm aperture were slightly power-dependent. Overall, there appeared to be a relationship between coercivity and nanoparticle size. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Comparative Study of Zirconium Nitride Multilayer Coatings: Crystallinity, In Vitro Oxidation Behaviour and Tribological Properties Deposited via Sputtering and Arc Deposition.
- Author
-
Dohm, Julius C., Schmidt, Susann, Puente Reyna, Ana Laura, Richter, Berna, Santana, Antonio, and Grupp, Thomas M.
- Subjects
SPUTTER deposition ,TOTAL knee replacement ,CRYSTAL structure ,MECHANICAL wear ,GRAIN size ,SURFACE coatings - Abstract
This study aims to evaluate and compare the properties of a biomedical clinically established zirconium nitride (ZrN) multilayer coating prepared using two different techniques: pulsed magnetron sputtering and cathodic arc deposition. The investigation focuses on the crystalline structure, grain size, in-vitro oxidation behaviour and tribological performance of these two coating techniques. Experimental findings demonstrate that the sputter deposition process resulted in a distinct crystalline structure and smaller grain size compared to the arc deposition process. Furthermore, in vitro oxidation caused oxygen to penetrate the surface of the sputtered ZrN top layer to a depth of 700 nm compared to 280 nm in the case of the arc-deposited coating. Finally, tribological testing revealed the improved wear rate of the ZrN multilayer coating applied by sputter deposition. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Sputter-Deposited Mo Thin Films: Characterization of Grain Structure and Monte Carlo Simulations of Sputtered Atom Energies and Incidence Angles
- Author
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Custer, J. O., Kalaswad, M., Kothari, R. S., Kotula, P. G., Ruggles, T., Hinojos, A., Dingreville, R., Henriksen, A., and Adams, D. P.
- Published
- 2024
- Full Text
- View/download PDF
41. Antiferromagnetic chromium thin films as piezoresistive sensor materials.
- Author
-
Schwebke, S. and Schultes, G.
- Subjects
- *
THIN films , *PIEZORESISTIVE effect , *CHROMIUM , *ANTIFERROMAGNETIC materials , *STRAIN gages , *SPUTTER deposition , *SILICON nitride films - Abstract
Sputter-deposited thin films of pure chromium and of chromium with small amounts of nitrogen are characterized regarding their electrical resistivity and strain dependence, i.e., piezoresistivity. They show a temperature dependent piezoresistive effect with gauge factors ranging approximately from 10 to 20. Related to this effect, they exhibit signs of a paramagnetic–antiferromagnetic transition at temperatures of 420 K and higher. For characterization, resistivity is measured at different strain levels: in a bending setup with a fixed radius and in a four-point bending system with reference strain gauges. Several parameter series of the sputter deposition of pure Cr films show that the higher gauge factor is correlated to a higher temperature coefficient of resistivity (TCR). The addition of nitrogen extends the range of TCR toward negative values, with gauge factors still in the same range as pure Cr. A Cr–N strain gauge is characterized and shows a linear, low-hysteresis strain–resistivity effect as well as a relatively large transverse sensitivity. Resistivity and gauge factor of one Cr and one Cr–N sample are measured from room temperature up to 600 K. These films have a resistivity anomaly indicating an antiferromagnetic ordering temperature T N that is much higher than in bulk Cr. The gauge factor has a maximum near T N and falls to small values at higher temperatures. The results indicate that the piezoresistivity of Cr and Cr-rich films is coupled to their spin-density wave (SDW) antiferromagnetism. Since the SDW state is known to be tunable through alloying, internal stress, and crystallinity, it appears that piezoresistivity can be influenced by these parameters as well. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
42. The measurement and impact of negative oxygen ions during reactive sputter deposition.
- Author
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Depla, D.
- Subjects
- *
ION bombardment , *ANIONS , *SPUTTER deposition , *ION energy , *REACTIVE sputtering , *MAGNETRON sputtering - Abstract
Many thin film applications are based on oxides. The optimization of the oxide properties is an on-going process and requires a deep understanding of the deposition process. A typical feature of reactive (magnetron) sputter deposition is the presence of negative oxygen ions. Two groups of ions can be identified based on their energy. Low energy ions are generated in the bulk of the discharge. The high energy ions are emitted from the oxide or oxidized target surface. As these ions are generated at the cathode, they are accelerated by the electric field toward the growing film. Depending on the discharge voltage and the powering method, their energy is typically several tenths to hundreds electron volt. As such the ions can have a strong impact on the film properties. In the case of magnetron sputtering, this will lead to inhomogenous film properties over the substrate facing the locally eroded target. Due to their high energy, the trajectory of negative ions can be easily predicted which has led to several strategies to avoid negative ion bombardment such as facing target sputtering and off-axis sputtering. This paper reviews several facets of the production, the measurements and the impact on the film properties of negative ions during reactive sputtering. Despite the many illustrative studies on the impact of negative oxygen ions, quantification is often lacking as the negative ion yield is only known for a few oxides. The compilation of several literature sources allows the discussed trends to be placed in a quantitative framework. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. Bowl Shaped Oxide‐Templated Gold Nanostructured Arrays and Structure‐Induced Hydrophilic–Hydrophobic Transition and Molecular Trapping Effect.
- Author
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Yang, Xiaowei, Lu, Yanyan, Zhao, Qian, Lei, Biao, Chen, Kang, Wei, Yi, Zhang, Hongwen, and Cai, Weiping
- Subjects
- *
GOLD , *SPUTTER deposition , *BORON nitride , *NANOPARTICLES , *HEAT treatment , *PHOTOTHERMAL effect , *TIN - Abstract
A facile and versatile methodology is developed for the synthesis of diverse gold nanostructured arrays employing an oxide secondary template combined with sputtering deposition. A bowl‐shaped tin oxide‐built array, with fine structure on its bowl edges, is first designed and prepared by solution‐dipping of an organic colloidal monolayer, drying, and heating treatment. This array is then used as a secondary template for a gold nanostructured array by sputtering deposition on it. By controlling the solution's concentration and drying rate to adjust the fine structure of the secondary template, various new gold nanostructured arrays with hexagonal arrangement are fabricated, including "graphene‐structured" gold nanoarray, non‐contact nanoparticle's ring array, closely contacted nanoring array, and bowl/nanoparticle binary composite nanoarray, achieving the structural diversity and morphological tunability of nanoarrays. Additionally, these gold nanostructured arrays can transition from hydrophilic to hydrophobic properties solely by adjusting their surface architecture. Importantly, the bowl‐shaped structural units within these gold nanoarrays demonstrate a marked capability for capturing target molecules that can only very weakly interact with plasmonic metals. This work offers an efficient route to achieve the structural diversity of nanoarrays, which is of significance in designing and fabricating foundational materials for the next generation of multifunctional nanodevices. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. Effect of substrate temperature on the structural properties of Tungsten Carbide and Tungsten-rich Tungsten Carbide films.
- Author
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Bist, Shristi, Pandey, Ratnesh K., Shah, Sejal, Kalita, Parswajit, Sarma, Arun, Sen, S., and Avasthi, D. K.
- Subjects
- *
FATIGUE limit , *TUNGSTEN carbide , *SPUTTER deposition , *DC sputtering , *SUBSTRATES (Materials science) , *FUSION reactors - Abstract
The unique mechanical properties of Tungsten Carbide (WC), such as fracture toughness, exceptional hardness, high melting temperature, outstanding thermal stability, anti-oxidation qualities fatigue and creep resistance, have made it a suitable industrial material for different applications. It is also considered to be a promising material for coating on plasma-facing walls in a Tokamak reactor. The aim of the present work is to study the effect of varying substrate temperature, concentration of tungsten (W) and annealing in the structural properties of WC films. The WC films are deposited on a silicon substrate at different substrate temperatures viz. RT (300 K), 400, 500, 600 and 700 K using DC magnetron sputtering. W-rich WC films were deposited keeping the power of WC constant (100 Watt) and varying W powers (10 Watt, 20 Watt, 30 Watt, 40 Watt) at room temperature. Later, these W-rich WC films were annealed at 800°C in a reducing atmosphere. Glancing incidence X-ray diffraction (GIXRD) and Raman spectroscopy of the films are performed for structural analysis. GIXRD of the WC films reveals that as-deposited RT films are amorphous. However, films which are either deposited at elevated substrate temperature or are annealed are crystalline. This is confirmed by Raman's measurements. It also indicates the presence of disorder and nanocrystalline phases due to temperature variations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
45. Designing a Stable Alloy Interlayer on Li Metal Anodes for Fast Charging of All-Solid-State Li Metal Batteries.
- Author
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Delaporte, Nicolas, Perea, Alexis, Collin-Martin, Steve, Léonard, Mireille, Matton, Julie, Demers, Hendrix, Clément, Daniel, Gariépy, Vincent, and Zhu, Wen
- Subjects
LITHIUM cells ,SPUTTER deposition ,VAPOR-plating ,SCANNING electron microscopes ,PLASMA deposition - Abstract
The deposition of a thin Li
x Sny alloy layer by plasma vapor deposition (PVD) on the surface of a Li foil is reported. The formation of a Li-rich alloy is confirmed by the volume expansion (up to 380%) of the layer and by the disappearance of metallic Sn peaks in the X-ray diffractogram. The layer has a much higher hardness than bare Li and can withstand aggressive cycling at 1C. Post-mortem scanning electron microscope observations revealed that the alloy layer remains intact even after fast cycling for hundreds of cycles. A concept of double modification by adding a thin ceramic/polymer layer deposited by a doctor blade on top of the Lix Sny layer was also reported to be efficient to reach long-term stability for 500 cycles at C/3. Finally, a post-treatment after Sn deposition consisting of a plasma cleaning of the Lix Sny alloy layer led to a strong improvement in the cycling performance at 1C. The surface is smoother and less oxidized after this treatment. The combination of a Li-rich alloy interlayer, the increase in hardness at the electrolyte/Li interface, and the absence of dissolution of the layer during cycling at high C-rates are reasons for such an improvement in electrochemical performance. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
46. High power impulse magnetron sputtering of a zirconium target.
- Author
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Suresh Babu, Swetha, Fischer, Joel, Barynova, Kateryna, Rudolph, Martin, Lundin, Daniel, and Gudmundsson, Jon Tomas
- Subjects
MAGNETRON sputtering ,GLOW discharges ,ELECTRON impact ionization ,ZIRCONIUM ,WORKING gases ,SPUTTER deposition - Abstract
High power impulse magnetron sputtering (HiPIMS) discharges with a zirconium target are studied experimentally and by applying the ionization region model (IRM). The measured ionized flux fraction lies in the range between 25% and 59% and increases with increased peak discharge current density ranging from 0.5 to 2 A/cm 2 at a working gas pressure of 1 Pa. At the same time, the sputter rate-normalized deposition rate determined by the IRM decreases in accordance with the HiPIMS compromise. For a given discharge current and voltage waveform, using the measured ionized flux fraction to lock the model, the IRM provides the temporal variation of the various species and the average electron energy within the ionization region, as well as internal discharge parameters such as the ionization probability and the back-attraction probability of the sputtered species. The ionization probability is found to be in the range 73%–91%, and the back-attraction probability is in the range 67%–77%. Significant working gas rarefaction is observed in these discharges. The degree of working gas rarefaction is in the range 45%–85%, higher for low pressure and higher peak discharge current density. We find electron impact ionization to be the main contributor to working gas rarefaction, with over 80% contribution, while kick-out by zirconium atoms and argon atoms from the target has a smaller contribution. The dominating contribution of electron impact ionization to working gas rarefaction is very similar to other low sputter yield materials. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
47. Biochemical and Microbiological Properties of the Cotton–Copper Composite Material Obtained via Sputter Deposition.
- Author
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Świerczyńska, Małgorzata, Mrozińska, Zdzisława, Juszczak, Michał, Woźniak, Katarzyna, and Kudzin, Marcin H.
- Subjects
PARTIAL thromboplastin time ,SPUTTER deposition ,MAGNETRON sputtering ,COMPOSITE materials ,ANTIBACTERIAL agents - Abstract
This study investigated the biochemical and microbiological properties of Cotton–Copper composite materials obtained using magnetron sputtering technology. Copper particles were precisely distributed on the fabric surface, ensuring free airflow without the need to create additional layers. The Cotton–Copper composite materials were subjected to physiochemical and biological investigations. The physiochemical analysis included the elemental analysis of composites (C, N, O, S, Cu) and analyses of their microscopic and surface properties (specific surface area and total pore volume). The biological investigations consisted of microbiological and biochemical–hematological tests, including evaluation of the activated partial thromboplastin time and prothrombin time. Experiments showed significant effectiveness of the antibacterial material against representative strains of fungi and bacterial species. We also demonstrated the ability of the cotton–copper material to interact directly with the plasmid DNA. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Biochemical Behavior, Influence on Cell DNA Condition, and Microbiological Properties of Wool and Wool–Copper Materials.
- Author
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Mrozińska, Zdzisława, Kaczmarek, Anna, Świerczyńska, Małgorzata, Juszczak, Michał, and Kudzin, Marcin H.
- Subjects
- *
WOOL , *PARTIAL thromboplastin time , *SPUTTER deposition , *COPPER , *BLOOD coagulation , *GRAM-negative bacteria - Abstract
The paper presents the study concerning the preparation and physio-chemical and biological properties of wool–copper (WO-Cu) materials obtained by the sputter deposition of copper onto the wool fibers. The WO-Cu material was subjected to physio-chemical and biological investigations. The physio-chemical investigations included the elemental analysis of materials (C, N, O, S, and Cu), their microscopic analysis, and surface properties analysis (specific surface area and total pore volume). The biological investigations consisted of the antimicrobial activity tests of the WO-Cu materials against colonies of Gram-positive (Staphylococcus aureus) bacteria, Gram-negative (Escherichia coli) bacteria, and fungal mold species (Chaetomium globosum). Biochemical–hematological tests included the evaluation of the activated partial thromboplastin time and pro-thrombin time. The tested wool–copper demonstrated the ability to interact with the DNA in a time-dependent manner. These interactions led to the DNA's breaking and degradation. The antimicrobial and antifungal activities of the WO-Cu materials suggest a potential application as an antibacterial/antifungal material. Wool–copper materials may be also used as customized materials where the blood coagulation process could be well controlled through the appropriate copper content. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Sputtering deposition of dense and low-resistive amorphous In2O3: Sn films under ZONE-T conditions of Thornton's structural diagram.
- Author
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Wada, Yoshiharu, Magdy, Wafaa, Takeda, Keigo, Mido, Yuta, Yamashita, Naoto, Okumura, Takamasa, Kamataki, Kunihiro, Koga, Kazunori, Hori, Masaru, Shiratani, Masaharu, and Itagaki, Naho
- Subjects
- *
SPUTTER deposition , *AMORPHOUS substances , *PLASMA density , *TIN , *AMORPHIZATION , *CARRIER density , *MAGNETRON sputtering - Abstract
We have fabricated smooth-surfaced amorphous In2O3:Sn (a-ITO) films at a high temperature of 550 °C, far above the typical crystallization threshold of 150 °C for ITO films. This achievement has been made possible by intentionally introducing N2 into the sputtering atmosphere, which maintains a low N atom incorporation of only a few atomic percent within the films. Positioned within ZONE-T of the Thornton diagram (higher-temperature region characterized by high film density), our method allows the preparation of films with superior film density about 6.96 g/cm3, substantially exceeding the density of 6.58 g/cm3 for conventional a-ITO films fabricated under ZONE-1 (low-temperature region) and approaching the bulk crystal density of In2O3 at 7.12 g/cm3. The films also feature a high carrier density of 5 × 1020 cm−3 and a remarkably low resistivity of 3.5 × 10−4 Ω cm, comparable to those of polycrystalline films. The analysis via vacuum-ultraviolet absorption spectroscopy on N and O atom densities in the plasma suggests that amorphization is primarily caused not by N atoms incorporated in the films but by those temporally adsorbed on the film surface, inhibiting crystal nucleation before eventually desorbing. Our findings will pave the way not only for broader applications of a-ITO films but also for the design of other amorphous materials at temperatures beyond their crystallization points. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. PVD‐Beschichtungen ermöglichen textile Kabel und Sensoren: Prozesskontrolle durch angepasste Energiebereiche.
- Author
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Hegemann, Dirk and Amberg, Martin
- Subjects
- *
PHYSICAL vapor deposition , *SPUTTER deposition , *PLASMA deposition , *PLASMA-wall interactions , *COATED textiles , *MAGNETRON sputtering , *WIRE - Abstract
Summary: PVD Coatings Enable Textile Wires and Sensors – Process control by adjusted energy ranges Plasma sputtering deposition is a Physical Vapor Deposition (PVD) method based on a weakly ionized gas, the plasma, that ablates atoms from a solid target material at vacuum conditions to deposit the sputtered atoms on a substrate. In this way, the plasma has two functions, i) the generation of high‐energy ions of several 100 eV accelerated to the target for sputtering, and ii) to support film growth by plasma‐surface interaction with particles bearing lower energies around ∼10 eV. For both processes, energy thresholds are present, which will be discussed in this article. Plasma sputtering deposition has wide spread industrial applications. As one example, the metallization of polymer fibers is demonstrated to obtain electrically conductive textile sensors and wires. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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