The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Two-dimensional crystals of Graphene Oxide (GO) were synthesized by modified Hummers method: flakes of specific lateral size 1–2 μm were obtained as a stable aqueous suspension. The size of GO flakes can be controlled via initial graphite powder grain size as well as via respective filtration or centrifugation of the GO solution. The concentration of GO in the solution can be varied between 4 mg/mL...
We show that graphene can be provide electro-optic properties to traditionally passive optical materials and enable efficient integrated active nanophotonic devices. We show devices with GHz absorption modulation based on ring resonators. We also report the first experimental demonstration of a graphene electro-refractive modulator with VπL of 0.14 V cm, and minimal absorption modulation based on...
Vacuum micro/nano electronic devices possess merits of radiation hardness, temperature tolerance, high working frequency and output power. It's regarded as the promising candidates for the application on ultra-high speed transistor [1, 2], portable and fast-switch X-ray source [3], free electron laser [4], field emission display [5] and so on. In the developing of modern vacuum electronic, to achieve...
Hyperdoping silicon with transition metals offers the potential of subbandgap photodetection, but metal impurities can be difficult to kinetically trap. Instabilities during solidification introduce large length-scale defects. We present guidelines for avoiding these instabilities, and electronic properties for layers that do not exhibit them.
Recently, we have showed a direct laser writing method that exploits nonlinear interactions to form subsurface modifications in silicon. Here, we use the technique to demonstrate laser-slicing of silicon and its applications.
Similar to their plasmonic counterparts, dielectric nanoantennas have the ability to manipulate the emission properties of nanoscale emitters placed in their vicinity. Most importantly, they can increase the radiative decay rate of emitters by coupling to Mie-type resonances and/or shape the emission into directional patterns [1]. While considerable theoretical work has been dedicated to the study...
Huygens' metasurfaces that utilize tailored Mie-type resonances of dielectric particles form a versatile platform for the design of ultra-thin and highly-efficient wavefront-shaping devices [1-3]. Dielectric metasurfaces typically yield higher efficiencies than comparable plasmonic structures due to their significantly lower absorption losses. Furthermore, it was shown that the superposition of the...
Transition-metal-dichalcogenides (TMDs), which exhibit an indirect electronic band gap as bulk crystals, can become direct semiconductors in the monolayer phase [1]. Such monolayer TMDs show unique optical properties arising from the strong two-dimensional confinement of excitons as well as from the reduction in crystal symmetry. However, the strong mismatch in length scale between the sub-nanometer...
With the continuous advances in the development of high-intensity lasers, laser-driven ion acceleration may become a compact alternative to produce ions with energies suitable for medical applications [1]. However, the unique properties of laser-accelerated ions, such as the mixed radiation field, a broad energy spectrum of up to 100% energy spread and ion fluxes exceeding 107 protons / cm2 / ns are...
The efficient characterization and validation of the underlying model of a quantum physical system is a central challenge in the development of quantum devices and for our understanding of foundational quantum physics. However, the impossibility to efficiently predict the behaviour of complex quantum models on classical machines makes this challenge to be intractable to classical approaches. Quantum...
Metamaterials and metasurfaces are artificial structures whose optical properties go beyond the natural behaviour of light. Their appeal revolves around the possibility to design the optical response by changing the geometry of the structure using essentially the same material constituents [1]. Some classes of metamaterials and metasurfaces can be fabricated over macroscopic areas and have strong...
Control of light by an external magnetic field is one of the important methods for modulation of its intensity and polarization. Magneto-optical effects at the nanoscale are usually observed in nanostructured hybrid materials or magnetoplasmonic crystals. In this work, we combine the advantages of all-dielectric resonant nanostructures and magnetic materials for creating compact active magneto-optical...
One of the main challenges in photonics is the integration of ultrafast coherent sources in silicon compatible platforms at the nanoscale [1]. Generally, the emission of ultra-short pulses is achieved by synchronizing the cavity modes of the system via external active components, such as, e.g., Q-switch or saturable absorbers. Consequently, the required optical setups are complex and difficult to...
Cu-Cu direct bonding under help of direct immersion gold (DIG) for multi-die fan-out wafer level package was demonstrated. Cu-Cu direct bonding is a critical technology for high-frequency applications. To solve challenges of conventional methods, the DIG was used. As a result, a cohesion failure was obtained in shear test.
The electrocardiographic tracing represents one of the most versatile pre-diagnostic tools and of greater clinical use at the present time. However, there are indicators that are difficult to observe by a health specialist, such as the so-called J-point and ST-segment elevation, useful in the assessment of ischemia. The present work proposes an improvement of the algorithm “Rising Falling Transition...
Low-threshold field emission is the intrinsic property for nanocarbon materials. Emission characteristics of planar field cathodes with carbon nanotubes (CNT) deposited from solution to Si, Al, Pd substrates were studied. The field emission threshold value for horizontally aligned CNT was found as low as 4 V/μm. However, the field enhancement in these samples is negligible (<10). We propose to...
This paper provides us with a detailed study of the structural and functional properties of heterojunction solar cell that is made up of two or more different type of semiconductor materials. Our objective is to analyze the formation of solar cells first, and in order to do that we have to focus on two parameters, lattice matching and epitaxial layer formation, that will provide sufficient photoconversion...
In this work the experimental results are presented showing the spectroscopic performance of the ASIC multichannel charge-sensitive preamplifier of TRACE (TRacking Array for light Charged particle Ejectiles). The results were obtained connecting a silicon pad detector to a custom-designed preamplifier board with eight ASIC CSPs. The detector and the board were put in a vacuum chamber with a triple...
A simple and effective method to grow GaN on Si substrates has been achieved. The method that GaN comes out from a submicron and deep hole with nearly zero dislocations above the mask is demonstrated. This work proves that reducing the epitaxy area by using mask and increasing the depth to width ratio of pattern contribute to filtering the dislocations and improving the quality of GaN.
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.