Search results for "Planar"
showing 10 items of 412 documents
New Results on High-Resolution 3-D CZT Drift Strip Detectors
2020
Intense research activities have been carry out in the development of room temperature gamma ray spectroscopic imagers, aiming to compete with the excellent energy resolution of high-purity germanium (HPGe) detectors (0.3 % FWHM at 662 keV) obtained after cryogenic cooling. Cadmium-zinc-telluride (CZT) detectors equipped with pixel, strip and virtual Frisch-grid electrode structures represented an appealing solution for room temperature measurements. In this work, we present the performance of new high-resolution CZT drift strip detectors (19.4 x 19.4 x 6 mm3), recently fabricated at IMEM-CNR of Parma (Italy) in collaboration with due2lab company (Reggio Emilia, Italy). The detectors, worki…
Improving the Long‐Term Stability of Doped Spiro‐Type Hole‐Transporting Materials in Planar Perovskite Solar Cells
2021
The improvement of the long-term stability of perovskite-based solar cells (PSCs) toward commercialization is closely linked to the development of cutting-edge charge-transporting materials. The progress on the design and the synthesis of new hole-transporting materials (HTMs) is synergistically attaining both top efficiencies and promising stability. Herein, the synthesis and characterization of two doped-HTMs based on electron-rich spiranic cores, namely, 9H-quinolinophenoxazine (spiro-POZ) and 9H-quinolinophenothiazine (spiro-PTZ), are presented. The novel HTMs exhibit excellent solubility, optimal highest occupied molecular orbital energy, and excellent thermal stability with glass tran…
Transparent conductive oxide photonic crystals on textured substrates
2011
Three-dimensional ZnO:Al photonic crystals were fabricated by atomic layer deposition on highly textured substrates. It turns out that these inverted opals consist of a thin intermediate disordered layer close to the textured substrate followed by a highly-ordered photonic crystal layer. The photonic crystals themselves exhibit comparable optical properties to those on planar substrates.
Flexible Laser Tracing Systems for Defining Thin Film Hybrid Geometries
1994
A recent programme of technical collaboration between Alelco, DIE of Palermo and CRES of Monreale has led to the development and operative confirmation of a technique for delineating conductive microgeometries on various types of Substrates. This technique, using a flexible System of laser microlithography on planar (2-D) or three-dimensional (3-D) surfaces, has led to the development of several types of thin film components for use at both low and high frequencies. © 1994, MCB UP Limited
Extended gate electrode arrays for extracellular signal recordings
2000
Abstract We have fabricated arrays of planar gold electrodes arranged in a matrix of 8×8 with active areas ranging from 6 to 30 μm in diameter. An electronic amplification circuitry based on commercial junction field-effect transistors was used where the gold sensor fields act as extended gate electrodes (EGE) of the transistors, which leads to a new approach for long-term extracellular recording systems in vitro. The high input resistance of the amplification circuitry allows the use of small planar bare gold electrodes without further modification which therefore extends the frequency range of the measuring set-up down to the DC-level. The performance of our recording system has been test…
Local Metamaterial-Based Waveguides in Gaps Between Parallel Metal Plates
2009
This letter presents a new metamaterial-based waveguide technology referred to as ridge gap waveguides. The main advantages of the ridge gap waveguides compared to hollow waveguides are that they are planar and much cheaper to manufacture, in particular at high frequencies such as for millimeter and sub- millimeter waves. The latter is due to the fact that there are no mechanical joints across which electric currents must float. The gap waveguides have lower losses than microstrip lines, and they are completely shielded by metal so no additional packaging is needed, in contrast to the severe packaging problems associated with microstrip circuits. The gap waveguides are realized in a narrow …
Functionalized planar Bragg grating sensor for the detection of BTX in solvent vapor
2012
We report on an optical planar Bragg grating evanescent wave refractive index sensor functionalized by a simple method against aromatic hydrocarbons such as benzene, toluene and xylene (BTX) in solvent vapor. To functionalize the sensor against BTX, substituted cyclodextrins are applied to the sensor surface using dip coating. Cyclodextrins have a hydrophobic cavity, which favors the accommodation of an organic molecule of appropriate dimensions leading to a non-covalent inclusion complex. The temporal sensor response reveals a multi-exponential rise towards an equilibrium state, whose level is found to be linearly related to the exposed analyte concentration. Taking into account the spectr…
Stable proton exchanged waveguides in Lithium Tantalate
2008
alpha, beta(1), and kappa(2) phases are investigated for planar waveguide fabrication by proton exchange in congruent lithium tantalate. The effective indices of planar waveguide eigenmodes were monitored over time, revealing that the exchange process induces aging instabilities in all phases except alpha.
Wideband impedance matrix representation of passive waveguide components based on cascaded planar junctions
2009
[1] A very efficient technique for the full-wave analysis of passive waveguide components, composed of the cascade connection of planar junctions, is presented. This novel technique provides the wideband generalized impedance matrix representation of the whole structure in the form of pole expansions, thus extracting the most expensive computations from the frequency loop. For this purpose, the structure is segmented into planar junctions and uniform waveguide sections, which are characterized in terms of wideband impedance matrices. Then, an efficient iterative algorithm for combining such matrices, and finally providing the wideband generalized impedance matrix of the complete structure, …
The geometry of the secant caustic of a planar curve
2018
The secant caustic of a planar curve $M$ is the image of the singular set of the secant map of $M$. We analyse the geometrical properties of the secant caustic of a planar curve, i.e. the number of branches of the secant caustic, the parity of the number of cusps and the number of inflexion points in each branch of this set. In particular, we investigate in detail some of the geometrical properties of the secant caustic of a rosette, i.e. a smooth regular oriented closed curve with non-vanishing curvature.