Breakdown Voltage Enhancement of Al0.1Ga0.9 N Channel HEMT with Recessed Floating Field Plate

Silicon - In this paper, electrical and microwave characteristics of Al0.1Ga0.9 N channel HEMTs was reported. The device performance were evaluated for conventional gate, field plate gate,...     

Influence of High-k Passivation Layer on Gate Field Plate AlGaN/GaN/AlGaN Double Heterojunction HEMT

Silicon - In this work, we have analysed the influence of passivation material such as Silicon dioxide (SiO2), Silicon Nitride (Si3N4), Aluminium oxide (Al2O3), Hafnium Silicon Oxide (HfSiO4),...     

Solar water splitting with p-SiC film on p-Si: Photoelectrochemical behavior and XPS characterization

The electrochemical properties of single-crystalline p-type 3C-SiC films on p-Si substrate were investigated as an electrode in H₂SO₄ aqueous solutions in dark and under white light illumination. The photoelectrochemical (PEC) measurements indicates the p-type 3C-SiC film on p-Si substrate can generate a cathodic photocurrent as a photocathode, which corresponds to hydrogen production, and generate an anodic photocurrent as a photoanode, which corresponds to oxygen evolution. The surface chemical states of the films were investigated by XPS. In order to observe the surface chemical state changes after PEC test, the range of applied potential to the electrode was divided into three zones: −3.6 to 0 V, 0–1.5 V and 1.5–4 V vs. Ag/AgCl. After separated PEC tests in these three areas, XPS shows the surface of the SiC film in the range of −3.6 to 0 V and 0–1.5 V was stable without oxidation except the band bending occurred. But in the range of 1.5–4 V the film surface was oxidized due to anodic oxidation.     

Improved device performance based on crosslinking of poly (3-hexylthiophene)

Diode devices (glass/ITO/polymer/Al) have been fabricated using poly (3-hexylthiophene) (P3HT) crosslinked with two different biaryl crosslinkers. Crosslinking was performed by exposing the thin films with different wt% of crosslinker to UV irradiation and progress of crosslinking was monitored by IR spectroscopy. An increase in hole mobility of two orders of magnitude has been observed after crosslinking.     

Realization of Multidimensional Digital Transfer Functions with Separable Numerator or Denominator Polynomials

In this paper a straightforward z-domain procedure for realizing multidimensional transfer functions with either numerator or denominator polynomial separable is presented. This procedure yields structures with minimum number of multipliers. It is shown that the number of delay elements can be reduced by selecting the optimum values for certain parameters. To facilitate this theorems that are applicable for some special cases are presented.     

XPS analysis of wet chemical etching of GaAs(110) by Br2–H2O: comparison of emersion and model experiments

We have applied photoelectron spectroscopy to investigate the surface composition after different surface treatments involving Br₂–H₂O mixtures in order to study wet chemical etching. Emersion experiments from Br₂–H₂O solution are compared with model experiments, in which Br₂–H₂O adsorbate and coadsorbate mixtures react with clean GaAs(110) surfaces. Our results indicate that Ga- and As-bromides formed initially are hydrolyzed to form the respective oxides. Without addition of Br₂, only slight oxidation of the surface takes place. There is an enrichment of Ga due to loss of As both in adsorption as well as in emersion experiments. Since in emersion experiments only a final situation is analyzed, the relative influence of surface reactivity and subsequent solvation effects cannot be distinguished easily, while model experiments give clear information on reaction products formed intermediately. However, model experiments differ in environment and temperature from the real solid–liquid interface. The presented results demonstrate that a combination of emersion and model experiments provide valuable insight into the mechanism of wet chemical etching on a microscopic level.     

Forced convection in cross flow of power law fluids over a tube bank

The forced convective heat transfer characteristics for incompressible power-law fluids past a bundle of circular cylinders have been investigated numerically. The cylinder-to-cylinder hydrodynamic interactions have been approximated via a simple cell model. The momentum and energy equations have been solved using a finite difference based numerical method for a range of physical and kinematic conditions. The role of the two commonly used thermal boundary conditions, namely, constant temperature or constant heat flux, on heat transfer characteristics has also been studied. Extensive numerical results elucidating the effect of shear-thinning viscosity on the values of Nusselt number have been obtained for Peclet numbers ranging from 1 to 5000, Reynolds number in the range 1-500, flow behaviour index 1?n?0.5 and three values of voidages, namely, 0.4, 0.5 and 0.6, typical of tubular heat exchangers and tube banks. Under all conditions, varying levels of enhancement in Nusselt number are observed due to shear-thinning behaviour. The surface averaged Nusselt number shows strong dependence on the values of voidage, power-law index, Reynolds and Peclet numbers. The paper is concluded by presenting comparisons with the scant experimental results available in the literature.     

Numerical Simulation of Impact of Bores against Inclined Walls

This work presents numerical simulations for the analysis of the impact of a bore against a wall. The 2D governing equations in the vertical plane are solved numerically using a variant of the simplified marker and cell method. Results are obtained for the maximum force and the runup height on the wall. Numerical results for the case of the vertical wall compare well with previous experimental data. A parametric study for the maximum force and the runup height on an inclined wall is presented.     

Simultanbestimmungsmethoden für die Elemente Kupfer,Zink, Eisen und Mangan sowie Natrium,Kalium, Calcium und Magnesium mittels Flammen-Atomabsorptionsspektrometrie (F-AAS)

Simultaneous determination of the elements copper, zinc, iron and manganese as well as sodium, potassium, calcium and magnesium by flame atomic absorption spectrometry (F-AAS). The elements Na, K, Ca, Mg, Cu, Zn, Fe and Mn are very important for the examination of human food and foodstuff in the light of nutritional physiology. Two simultaneous determination methods for these elements with flame atomic absorption spectrometry (F-AAS) are presented. The sensitivity of the F-AAS is sufficient for these examinations. Using the calibration and the method of standard addition resp. and “Schinkellösung” (caesiumchlorid lanthanumchlorid buffer solution), the simultaneous determination of Na, K, Ca and Mg is possible. The detection limits of Na, K, Ca and Mg depend on the simultaneous determination of the elements, the used wavelengths and the kind of the examined samples (30 mg Na, 24 mg K, 1,9 mg Ca and 0,46 mg Mg per kg fresh matter). The detection limits for Cu, Zn, Fe and Mn with the simultaneous determination are 0,61 mg Cu, 0,14 mg Zn, 3,8 mg Fe and 0,44 mg Mn per kg sample. The new methods are tested with the standard reference materials CRM No 278 (Mussel Tissue), CMR No 185 (Bovine Liver) and CRM No 189 (Wholemeal Flour) and with selected samples.     

Rank-one LMI Approach to Stability of 2-D Polynomial Matrices

Multidimensional Systems and Signal Processing -