Jet delivery system for Raman scattering on bio-inorganic compounds
We present a micro-jet sample delivery system for Ramanmeasurements. Compared to cuvettemeasurements, the observed Raman signal is enhanced by more than one order of magnitude and does not contain signal distortions from the liquid-glass interface. Furthermore, the signal stability of repeatedmeasurements is enhanced due to reduced sample damage effects by constantly replenishing the sample. This allows the study of sensitive samples that can only be produced in low concentrations. Our setup consists of a controlled sample environment that can be either under vacuum or an exchange gas, which allows the study of samples tha...
Source: Applied Physics Letters - November 22, 2016 Category: Physics Authors: A. Wetzel, F. Biebl, K. R. Beyerlein, J. Stanek, L. Gumprecht, A. Hoffmann, S. Herres-Pawlis, S. Bajt, H. N. Chapman, B. Grimm-Lebsanft, D. Rukser and M. R übhausen Source Type: research
An organic water-gated ambipolar transistor with a bulk heterojunction active layer for stable and tunable photodetection
Organic water-gatedtransistors (OWGTs) have emerged as promising sensing architectures for biomedical applications and environmental monitoring due to their ability ofin-situ detection of biological substances with high sensitivity and low operation voltage, as well as compatibility with various read-out circuits. Tremendous progress has been made in the development of p-type OWGTs. However, achieving stable n-type operation in OWGTs due to the presence of solvated oxygen in water is still challenging. Here, we report an ambipolar OWGT based on a bulkheterojunction active layer, which exhibits a stable hole and electrontra...
Source: Applied Physics Letters - November 22, 2016 Category: Physics Authors: Haihua Xu, Qingqing Zhu, Tongyuan Wu, Wenwen Chen, Guodong Zhou, Jun Li, Huisheng Zhang and Ni Zhao Source Type: research
Integration of colloidal silicon nanocrystals on metal electrodes in single-electron transistor
We develop a facile process to integratecolloidal silicon nanocrystals (Si NCs) withmetalelectrodes in a single-electron transistor byself-assembly.Gold(Au)surface is modified by an amine-terminatedself-assembled monolayer to have a positive potential. All-inorganic boron (B) and phosphorus (P)codoped Si NCs, with a negativesurface potential and size-controllability, are selectively adsorbed on an amine-terminatedAusurface by electrostatic attraction. We demonstrate the fabrication of SETs consisting of electroless-platedAu nanogapelectrodes andcodoped Si NCs using this process and observation of clear Coulomb diamonds at ...
Source: Applied Physics Letters - November 22, 2016 Category: Physics Authors: Yasuhiro Higashikawa, Yasuo Azuma, Yutaka Majima, Shinya Kano and Minoru Fujii Source Type: research
Low power phase change memory switching of ultra-thin In3Sb1Te2 nanowires
We report on the fabrication and electrical characterization of phase change memory (PCM) devices formed by In3Sb1Te2chalcogenide nanowires (NWs), with diameters as small as 20 nm. The NWs were self-assembled bymetal organic chemical vapor deposition via the vapor –liquid–solid method, catalyzed byAu nanoparticles. Reversible and well reproducible memory switching of the NWs between low and highresistance states was demonstrated. The conduction mechanism of the highresistance state was investigated according to a trap-limited model for electrical transport in theamorphous phase. The size of the amorphized portion of...
Source: Applied Physics Letters - November 22, 2016 Category: Physics Authors: S. Selmo, R. Cecchini, S. Cecchi, C. Wiemer, M. Fanciulli, E. Rotunno, L. Lazzarini, M. Rigato, D. Pogany, A. Lugstein and M. Longo Source Type: research
Insight into electrocaloric cooling power in multilayer capacitors using infra-red camera
Compact multilayer capacitors(MLCs) have attracted strong interest as the most promising elements for the design of electrocaloric prototypes. Recent theoretical simulations have predicted thatMLCs could permit a sustained cooling power. However, direct experimental evidence is still lacking. Here, we use an infra-redcamera to characterize the cooling power of commercialMLCs by combining both spatially and temporally resolvedmeasurements. We also compare the experimental data with theoreticalmodels in order to highlight the routes for developing and optimizing the future MLC-based devices as well as themeasurement conditio...
Source: Applied Physics Letters - November 22, 2016 Category: Physics Authors: Yang Liu, Herv é Strozyk, Brahim Dkhil and Emmanuel Defay Source Type: research
Adiabatic magnetocaloric effect in Ni50Mn35In15 ribbons
Heusler-type Ni-Mn-based metamagnetic shape memory alloys (MetaMSMAs) are promising candidates for magnetic refrigeration. To increase heat exchange rate and efficiency of cooling, thematerial should have a high surface/volume ratio. In this work, the typicalNi50Mn35In15 MetaMSMA was selected to fabricate thin ribbons by melt-spinning. The characteristic transformations of the ribbons were determined by calorimetry, X-ray diffraction, scanning electron microscopy and thermomagnetizationmeasurements. The inverse and conventional magnetocaloric effects(MCEs) associated with the martensitic transformation (MT) and theferromag...
Source: Applied Physics Letters - November 22, 2016 Category: Physics Authors: P. Álvarez-Alonso, C. O. Aguilar-Ortiz, J. P. Camarillo, D. Salazar, H. Flores-Zúñiga and V. A. Chernenko Source Type: research
On reduction of current leakage in GaN by carbon-doping
Carbon-doping is proposed to reduce the dislocation-mediatedleakage currents in theGaN buffer layers.GaN:C grown by metalorganic vapor phase epitaxy using propane shows excellent quality up to [C] = 6.7 × 1018 cm−3. Locally probing dislocations bysurface scanning potentialmicroscopy reveal a transition from mostly neutral or weaklycharged regions to dominantly negativelycharged regions relative to the surrounding area at highdoping levels. A relation betweenleakage currents and the relative dislocationcharge state exists. Minimumleakage current is achieved if the dominantcharge state of dislocation regions beco...
Source: Applied Physics Letters - November 22, 2016 Category: Physics Authors: Aqdas Fariza, Andreas Lesnik, J ürgen Bläsing, Marc P. Hoffmann, Florian Hörich, Peter Veit, Hartmut Witte, Armin Dadgar and André Strittmatter Source Type: research
Double-pulse femtosecond laser peening of aluminum alloy AA5038: Effect of inter-pulse delay on transient optical plume emission and final surface micro-hardness
Double-pulse ablativefemtosecond laser peening of the AA5038aluminum alloy surface in the phase explosion regime results in its enhancedmicrohardness, which monotonously decreases till the initial value versus inter-pulse delay, increasing on a sub-nanosecond timescale. Opticalemission spectroscopy of the double-pulse ablative plume reveals the same trend in the yield of the corresponding atomic and ion emission versus inter-pulse delay, enlightening the interaction of the secondfemtosecond laser pump pulse with the surface and the resulting plume. (Source: Applied Physics Letters)
Source: Applied Physics Letters - November 22, 2016 Category: Physics Authors: E. I. Ageev, V. Yu. Bychenkov, A. A. Ionin, S. I. Kudryashov, A. A. Petrov, A. A. Samokhvalov and V. P. Veiko Source Type: research
Room-temperature mid-infrared quantum well lasers on multi-functional metamorphic buffers
The modern commercial optoelectronic infrastructure rests on a foundation of only a few, select semiconductor materials, capable of serving as viable substrates for devices. Any new active device, to have any hope of moving past the laboratory setting, must demonstrate compatibility with these substratematerials. Across much of the electromagnetic spectrum, this simple fact has guided the development of lasers, photodetectors, and other optoelectronic devices. In this work, we propose and demonstrate the concept of amulti-functional metamorphic buffer (MFMB) layer that not only allows forgrowth of highly lattice-mismatched...
Source: Applied Physics Letters - November 22, 2016 Category: Physics Authors: Daehwan Jung, Lan Yu, Sukrith Dev, Daniel Wasserman and Minjoo Larry Lee Source Type: research
Continuous monitoring of the bulk oxidation states in LixNi1/3Mn1/3Co1/3O2 during charging and discharging
Operandomagnetic susceptibility measurements on theLixNi1/3Mn1/3Co1/3O2cathode material during repetitiveelectrochemical cycling were performed, enabling a continuous and bulk sensitive monitoring of the charge compensation process. Upon charging and Li extraction down to the Li contents ofx = 1/3, exclusivelyNi undergoesoxidation in two consecutive steps, namely,Ni2+→Ni3+ forx > 2/3 andNi3+→Ni4+ for 2/3 > x > 1/3 with a continuous transition in between. In the regime of low Li concentrationsx (Source: Applied Physics Letters)
Source: Applied Physics Letters - November 21, 2016 Category: Physics Authors: G. Klinser, S. Topolovec, H. Kren, S. Koller, W. Goessler, H. Krenn and R. W ürschum Source Type: research
Poroelasticity of cell nuclei revealed through atomic force microscopy characterization
With great potential in precision medical application,cell biomechanics is rising as a hot topic in biology.Cell nucleus, as the largest component withincell, not only contributes greatly to thecell's mechanical behavior, but also serves as the most vital component withincell. However,cell nucleus' mechanics is still far from unambiguous up to now. In this paper, we attempted to characterize and evaluate the mechanical property of isolatedcell nuclei usingAtomic Force Microscopy with a tipless probe. As indicated from typical indentation, changing loading rate andstress relaxation experiment results,cell nuclei showed sign...
Source: Applied Physics Letters - November 21, 2016 Category: Physics Authors: Fanan Wei, Fei Lan, Bin Liu, Lianqing Liu and Guangyong Li Source Type: research
Enhancement-mode Ga2O3 wrap-gate fin field-effect transistors on native (100) β-Ga2O3 substrate with high breakdown voltage
Sn-doped gallium oxide (Ga2O3) wrap-gate fin-array field-effect transistors (finFETs) were formed by top-down BCl3plasma etching on a native semi-insulating Mg-doped (100) β-Ga2O3 substrate. The fin channels have a triangular cross-section and are approximately 300 nm wide and 200 nm tall. FinFETs, with 20 nm Al2O3 gate dielectric and ∼2 μm wrap-gate, demonstrate normally-off operation with a threshold voltage between 0 and +1 V during high-voltage operation. TheION/IOFF ratio is greater than 105 and is mainly limited by high on-resistance that can be significantly improved. AtVG = 0, a finFET with 21...
Source: Applied Physics Letters - November 21, 2016 Category: Physics Authors: Kelson D. Chabak, Neil Moser, Andrew J. Green, Dennis E. Walker Jr., Stephen E. Tetlak, Eric Heller, Antonio Crespo, Robert Fitch, Jonathan P. McCandless, Kevin Leedy, Michele Baldini, Gunter Wagner, Zbigniew Galazka, Xiuling Li and Gregg Jessen Source Type: research
Electron transport through a single nanocrystalline silicon quantum dot between nanogap electrodes
We experimentally study the electron transport through a single nanocrystallinesiliconquantum dot between the nanogapelectrodes. We fabricate the device bydepositing a nanocrystal into an ∼10-nm gap using a very high frequency plasma cell. The Coulombdiamond size depends on the number of electrons at 4.5 K, which indicates that even–odd shell filling occurs. The charging energy is estimated to be ∼11 meV, which is consistent with the size of thesilicon nanocrystal. The perpendicularmagnetic field dependence of the Coulombdiamonds demonstrates theZeeman splitting as well as orbital energy evolution. (Source: Applied Physics Letters)
Source: Applied Physics Letters - November 21, 2016 Category: Physics Authors: T. Sawada, T. Kodera and S. Oda Source Type: research
An experimental and computational study of size-dependent contact-angle of dewetted metal nanodroplets below its melting temperature
Decorating 1D nanostructures (e.g.,wires and tubes) withmetalnanoparticles serves as a hierarchical approach to integrate the functionalities ofmetal oxides, semiconductors, andmetals. This paper examines a simple and low-temperature approach to self-assemblinggoldnanoparticles (Au-np) —a common catalytic material—onto siliconnanowires (SiNWs). A conformal ultra-thin film (i.e., (Source: Applied Physics Letters)
Source: Applied Physics Letters - November 21, 2016 Category: Physics Authors: Bruno P. Azeredo, Saikumar R. Yeratapally, Josh Kacher, Placid M. Ferreira and Michael D. Sangid Source Type: research
Si:SrTiO3-Al2O3-Si:SrTiO3 multi-dielectric architecture for metal-insulator-metal capacitor applications
Metal-insulator-metal (MIM)capacitors comprised of amorphous Si:SrTiO3-Al2O3-Si:SrTiO3 multi-dielectric architecture have been fabricated employing a combination of pulsed laser and atomic layer deposition techniques. The voltage linearity, temperature coefficients ofcapacitance,dielectric and electrical properties upon thickness were studied under a wide range of temperature (200 –400 K) andelectric field stress ( ±1.5 MV/cm). A highcapacitance density of 31 fF/μm2, a low voltage coefficient ofcapacitance of 363 ppm/V2, a low temperature coefficient ofcapacitance of (Source: Applied Physics Letters)
Source: Applied Physics Letters - November 21, 2016 Category: Physics Authors: Sita Dugu, Shojan P. Pavunny, James F. Scott and Ram S. Katiyar Source Type: research
