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Suche nach „[IQMA]“ hat 159 Publikationen gefunden
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    NachhaltigElektrotechnik und MedientechnikIQMA

    Zeitschriftenartikel

    S. Chen, L. Jiang, M. Buckwell, X. Jing, Y. Ji, E. Grustan-Gutierrez, Günther Benstetter, F. Hui, Y. Shi, M. Rommel, A. Paskaleva, W. Ng, A. Mehonic, A. Kenyon, M. Lanza

    On the Limits of Scalpel AFM for the 3D Electrical Characterization of Nanomaterials

    Advanced Functional Materials, vol. 28, no. 52

    2018

    DOI: 10.1002/adfm.201802266

    Abstract anzeigen

    Conductive atomic force microscopy (CAFM) has been widely used for electrical characterization of thin dielectrics by applying a gentle contact force that ensures a good electrical contact without inducing additional high‐pressure related phenomena (e.g., flexoelectricity, local heat, scratching). Recently, the CAFM has been used to obtain 3D electrical images of thin dielectrics by etching their surface. However, the effect of the high contact forces/pressures applied during the etching on the electrical properties of the materials has never been considered. By collecting cross‐sectional transmission electron microscopy images at the etched regions, it is shown here that the etching process can modify the morphology of Al2O3 thin films (producing phase change, generation of defects, and metal penetration). It is also observed that this technique severely modifies the electrical properties of pSi and TiO2 wafers during the etching, and several behaviors ignored in previous studies, including i) observation of high currents in the absence of bias, ii) instabilities of etching rate, and iii) degradation of CAFM tips, are reported. Overall, this work should contribute to understand better the limitations of this technique and disseminate it among those applications in which it can be really useful.

    Elektrotechnik und MedientechnikIQMA

    Vortrag

    Manuel Bogner, C. Yang, Günther Benstetter, Y. Fu, M. Grundmann

    Nanoscale thermal properties of next generation transparent/flexible thermoelectric copper iodide films

    Posterpräsentation

    5. Tag der Forschung, Deggendorf

    2018

    NachhaltigElektrotechnik und MedientechnikIQMA

    Zeitschriftenartikel

    L. Liu, S. Li, D. Liu, Günther Benstetter, Y. Zhang, Y. Hong, H. Fan, W. Ni, Q. Yang, Y. Wu, Z. Bi

    Surface damages of polycrystalline W and La2O3-doped W induced by high-flux He plasma irradiation

    Journal of Nuclear Materials, vol. 501, no. April, pp. 275-281

    2018

    Abstract anzeigen

    In this study, polycrystalline tungsten (W) and three oxide dispersed strengthened W with 0.1 vol %, 1.0 vol % and 5.0 vol % lanthanum trioxide (La2O3) were irradiated with low-energy (200 eV) and high-flux (5.8 × 1021 or 1.4 × 1022 ions/m2⋅s) He+ ions at elevated temperature. After He+ irradiation at a fluence of 3.0 × 1025/m2, their surface damages were observed by scanning electron microscopy, energy dispersive spectroscopy, scanning electron microscopy-electron backscatter diffraction, and conductive atomic force microscopy. Micron-sized holes were formed on the surface of W alloys after He+ irradiation at 1100 K. Analysis shows that the La2O3 grains doped in W were sputtered preferentially by the high-flux He+ ions when compared with the W grains. For irradiation at 1550 K, W nano-fuzz was formed at the surfaces of both polycrystalline W and La2O3-doped W. The thickness of the fuzz layers formed at the surface of La2O3-doped W is 40% lower than the one of polycrystalline W. The presence of La2O3 could suppress the diffusion and coalescence of He atoms inside W, which plays an important role in the growth of nanostructures fuzz.

    NachhaltigElektrotechnik und MedientechnikIQMAMaschinenbau und Mechatronik

    Beitrag (Sammelband oder Tagungsband)

    Günther Benstetter, Alexander Hofer, D. Liu, Werner Frammelsberger, M. Lanza

    Chapter 3: Fundamentals of CAFM Operation Modes

    Conductive Atomic Force Microscopy: Applications in Nanomaterials, Weinheim

    2017

    ISBN: 978-3-527-34091-0

    Elektrotechnik und MedientechnikIQMA

    Vortrag

    Manuel Bogner, C. Yang, Günther Benstetter, Y. Fu, M. Grundmann

    Nanoscale thermal properties of next generation transparent/flexible thermoelectric copper iodide films

    Posterpräsentation

    5th Nano Today Conference, Hawaii, USA

    2017

    NachhaltigElektrotechnik und MedientechnikIQMAMaschinenbau und Mechatronik

    Beitrag (Sammelband oder Tagungsband)

    Tobias Berthold, Günther Benstetter, Werner Frammelsberger, Manuel Bogner, R. Rodríguez, M. Nafría

    Protective nanometer films for reliable Cu-Cu connections

    Best Paper Award

    Proceedings of the 28th European Symposium on Reliability of Electron Devices, Failure Physics and Analysis (ESREF) [25-28 September, 2017; Bordeaux, Frankreich]

    2017

    NachhaltigElektrotechnik und MedientechnikIQMA

    Zeitschriftenartikel

    C. Yang, D. Souchay, M. Kneiß, Manuel Bogner, H. Wei, M. Lorenz, O. Oeckler, Günther Benstetter, Y. Fu, M. Grundmann

    Transparent flexible thermoelectric material based on non-toxic earth-abundant p-type copper iodide thin film

    nature COMMUNICATIONS, no. July, pp. 1-7

    2017

    DOI: 10.1038/ncomms1607

    Abstract anzeigen

    Thermoelectric devices that are flexible and optically transparent hold unique promise for future electronics. However, development of invisible thermoelectric elements is hindered by the lack of p-type transparent thermoelectric materials. Here we present the superior room-temperature thermoelectric performance of p-type transparent copper iodide (CuI) thin films. Large Seebeck coefficients and power factors of the obtained CuI thin films are analysed based on a single-band model. The low-thermal conductivity of the CuI films is attributed to a combined effect of the heavy element iodine and strong phonon scattering. Accordingly, we achieve a large thermoelectric figure of merit of ZT=0.21 at 300 K for the CuI films, which is three orders of magnitude higher compared with state-of-the-art p-type transparent materials. A transparent and flexible CuI-based thermoelectric element is demonstrated. Our findings open a path for multifunctional technologies combing transparent electronics, flexible electronics and thermoelectricity.

    NachhaltigElektrotechnik und MedientechnikIQMAMaschinenbau und Mechatronik

    Zeitschriftenartikel

    Tobias Berthold, Günther Benstetter, Werner Frammelsberger, R. Rodríguez, M. Nafría

    Numerical Study of Hydrodynamic Forces for AFM Operations in Liquid Scanning (Article ID 6286595, 12 pages)

    Scanning, no. Article ID 6286595, pp. 1-12

    2017

    DOI: 10.1155/2017/6286595

    Abstract anzeigen

    For advanced atomic force microscopy (AFM) investigation of chemical surface modifications or very soft organic sample surfaces, the AFM probe tip needs to be operated in a liquid environment because any attractive or repulsive forces influenced by the measurement environment could obscure molecular forces. Due to fluid properties, the mechanical behavior of the AFM cantilever is influenced by the hydrodynamic drag force due to viscous friction with the liquid. This study provides a numerical model based on computational fluid dynamics (CFD) and investigates the hydrodynamic drag forces for different cantilever geometries and varying fluid conditions for Peakforce Tapping (PFT) in liquids. The developed model was verified by comparing the predicted values with published results of other researchers and the findings confirmed that drag force dependence on tip speed is essentially linear in nature. We observed that triangular cantilever geometry provides significant lower drag forces than rectangular geometry and that short cantilever offers reduced flow resistance. The influence of different liquids such as ultrapure water or an ethanol-water mixture as well as a temperature induced variation of the drag force could be demonstrated. The acting forces are lowest in ultrapure water, whereas with increasing ethanol concentrations the drag forces increase.

    NachhaltigElektrotechnik und MedientechnikIQMAMaschinenbau und Mechatronik

    Zeitschriftenartikel

    Tobias Berthold, Günther Benstetter, Werner Frammelsberger, Manuel Bogner, R. Rodríguez, M. Nafría

    Protective nanometer films for reliable Cu-Cu connections

    Microelectronics Reliability, vol. 76-77, no. September, pp. 383-389

    2017

    DOI: 10.1016/j.microrel.2017.07.001

    NachhaltigElektrotechnik und MedientechnikIQMA

    Zeitschriftenartikel

    X. Jing, Emanuel Panholzer, X. Song, E. Grustan-Gutierrez, F. Hui, Y. Shi, Günther Benstetter, Y. Illarionov, T. Grasser, M. Lanza

    Fabrication of scalable and ultra low power photodetectors with high light/dark current ratios using polycrystalline monolayer MoS2 sheets

    Nano Energy, vol. 30, no. December, pp. 494-502

    2016

    DOI: 10.1016/j.nanoen.2016.10.032

    Elektrotechnik und MedientechnikIQMA

    Vortrag

    Alexander Hofer, Tobias Berthold, A. Greppmair, M. Brandt, Günther Benstetter

    Nanoscale electrical conductivity of laser-sintered Ge nanoparticle layers

    The 8th International Conference On Technological Advances Of Thin Films and Surface Coatings (ThinFilms 2016), Singapur, Singapur

    2016

    Elektrotechnik und MedientechnikIQMA

    Vortrag

    Alexander Hofer, Tobias Berthold, A. Greppmair, Günther Benstetter, M. Brandt

    Nanoscale characterization of laser-sintered Ge nanoparticle layers

    2nd International Conference on Functional Integrated nano Systems (nanoFIS), Graz, Österreich

    2016

    NachhaltigElektrotechnik und MedientechnikIQMA

    Zeitschriftenartikel

    H. Fan, Y. You, W. Ni, Q. Yang, L. Liu, Günther Benstetter, D. Liu, C. Liu

    Surface degeneration of W crystal irradiated with low-energy hydrogen ions

    Scientific Reports (Nature Publishing Group), vol. 6, no. Article number: 23738

    2016

    DOI: 10.1038/srep23738

    Abstract anzeigen

    The damage layer of a W (100) crystal irradiated with 120 eV hydrogen ions at a fluence of up to 1.5 × 1025/m2 was investigated by scanning electron microscopy and conductive atomic force microscopy (CAFM). The periodic surface degeneration of the W crystal at a surface temperature of 373 K was formed at increasing hydrogen fluence. Observations by CCD camera and CAFM indicate the existence of ultrathin surface layers due to low-energy H irradiation. The W surface layer can contain a high density of nanometer-sized defects, resulting in the thermal instability of W atoms in the surface layer. Our findings suggest that the periodic surface degeneration of the W crystal can be ascribed to the lateral erosion of W surface layers falling off during the low-energy hydrogen irradiation. Our density functional theory calculations confirm the thermal instability of W atoms in the top layer, especially if H atoms are adsorbed on the surface.

    NachhaltigElektrotechnik und MedientechnikIQMA

    Zeitschriftenartikel

    L. Liu, D. Liu, Y. Hong, H. Fan, W. Ni, Q. Yang, Z. Bi, Günther Benstetter, S. Li

    High-flux He+ irradiation effects on surface damages of tungsten under ITER relevant conditions

    Journal of Nuclear Materials, vol. 471, no. April, pp. 1-7

    2016

    DOI: 10.1016/j.jnucmat.2016.01.001

    Abstract anzeigen

    A large-power inductively coupled plasma source was designed to perform the continuous helium ions (He+) irradiations of polycrystalline tungsten (W) under International Thermonuclear Experimental Reactor (ITER) relevant conditions. He+ irradiations were performed at He+ fluxes of 2.3 × 1021–1.6 × 1022/m2 s and He+ energies of 12–220 eV. Surface damages and microstructures of irradiated W were observed by scanning electron microscopy. This study showed the growth of nano-fuzzes with their lengths of 1.3–2.0 μm at He+ energies of >70 eV or He+ fluxes of >1.3 × 1022/m2 s. Nanometer-sized defects or columnar microstructures were formed in W surface layer due to low-energy He+ irradiations at an elevated temperature (>1300 K). The diffusion and coalescence of He atoms in W surface layers led to the growth and structures of nano-fuzzes. This study indicated that a reduction of He+ energy below 12–30 eV may greatly decrease the surface damage of tungsten diverter in the fusion reactor.

    NachhaltigElektrotechnik und MedientechnikIQMA

    Zeitschriftenartikel

    Y. Ji, H. Fei, Y. Shi, V. Iglesias, D. Lewis, N. Jiebin, S. Long, M. Liu, Alexander Hofer, Werner Frammelsberger, Günther Benstetter, A. Scheuermann, P. McIntyre, M. Lanza

    Characterization of the photocurrents generated by the laser of atomic force microscopes

    Review of Scientific Instruments, vol. 87, no. 8

    2016

    DOI: 10.1063/1.4960597

    Abstract anzeigen

    The conductive atomic force microscope (CAFM) has become an essential tool for the nanoscale electronic characterization of many materials and devices. When studying photoactive samples, the laser used by the CAFM to detect the deflection of the cantilever can generate photocurrents that perturb the current signals collected, leading to unreliable characterization. In metal-coated semiconductor samples, this problem is further aggravated, and large currents above the nanometer range can be observed even without the application of any bias. Here we present the first characterization of the photocurrents introduced by the laser of the CAFM, and we quantify the amount of light arriving to the surface of the sample. The mechanisms for current collection when placing the CAFM tip on metal-coated photoactive samples are also analyzed in-depth. Finally, we successfully avoided the laser-induced perturbations using a two pass technique: the first scan collects the topography (laser ON) and the second collects the current (laser OFF). We also demonstrate that CAFMs without a laser (using a tuning fork for detecting the deflection of the tip) do not have this problem.

    NachhaltigElektrotechnik und MedientechnikIQMA

    Vortrag

    K. Schiebl, Alexander Hofer, Günther Benstetter

    Atomic Force Microscopy analysis of laser-sintered Germanium nanoparticles for thermoelectric applications

    3rd International Congress on Energy Efficiency and Energy Related Materials (ENEFM), Oludeniz, Türkei

    2015

    NachhaltigElektrotechnik und MedientechnikIQMA

    Vortrag

    Günther Benstetter, Alexander Hofer, A. Greppmair, M. Brandt

    A review of physical characterization methods for nanostructured thermoelectric materials

    Invited Talk

    3rd International Congress on Energy Efficiency and Energy Related Materials (ENEFM), Oludeniz, Türkei

    2015

    NachhaltigElektrotechnik und MedientechnikIQMA

    Zeitschriftenartikel

    Q. Yang, Y.-W. You, L. Liu, H. Fan, W. Ni, D. Liu, C. Liu, Günther Benstetter, Y. Wang

    Nanostructured fuzz growth on tungsten under low-energy and high-flux He irradiation

    Scientific Reports (Nature Publishing Group), vol. 5, no. Article number: 10959, pp. 1-9

    2015

    DOI: 10.1038/srep10959

    NachhaltigElektrotechnik und MedientechnikIQMA

    Zeitschriftenartikel

    W. Ni, Q. Yang, H. Fan, L. Liu, Tobias Berthold, Günther Benstetter, D. Liu

    Ordered arrangement of irradiation-induced defects of polycrystalline tungsten irradiated with low-energy hydrogen ions

    Journal of Nuclear Materials, vol. 464, pp. 216-220

    2015

    NachhaltigElektrotechnik und MedientechnikIQMA

    Zeitschriftenartikel

    Q. Yang, H. Fan, W. Ni, L. Liu, Tobias Berthold, Günther Benstetter, D. Liu, Y. Wang

    Observation of interstitial loops in He+ irradiated W by conductive atomic force microscopy

    Acta Materialia, vol. 92, pp. 178-188

    2015