Nagoya Institute of Technology

About: Nagoya Institute of Technology is a education organization based out in Nagoya, Japan. It is known for research contribution in the topics: Thin film & Catalysis. The organization has 10766 authors who have published 19140 publications receiving 255696 citations. The organization is also known as: Nagoya Kōgyō Daigaku & Nitech.

1.4-kV Breakdown Voltage for AlGaN/GaN High-Electron-Mobility Transistors on Silicon Substrate

Abstract: In this letter, we present the device characteristics of AlGaN/GaN heterostructures grown on 4-in Si using various buffer thicknesses (TBuf). The transmission electron microscopic image confirms a low dislocation density (9.7 × 107 cm-2) for our epilayers grown using thick buffer layers. An increase in mobility and a decrease in sheet resistance of these samples were observed owing to improved crystal quality for GaN on thick buffer. High electron-mobility transistors (HEMTs) tested for three-terminal off breakdown voltage (3TBV ) show signs of breakdown voltage saturation for gate-drain length (Lgd) exceeding 15 μm. However, an increase in TBuf causes a drastic increase in 3TBV , and a high 3TBV of 1.4 kV was observed with a specific on-resistance of 9.6 mΩ · cm2. A figure of merit (FOM = BV2/Ron) of 2.6 × 108 V2 · Ω-1 · cm-2 was observed for our devices, which is the highest for an AlGaN/GaN HEMT grown on Si.

A sterically demanding organo-superbase avoids decomposition of a naked trifluoromethyl carbanion directly generated from fluoroform.

Abstract: A simple strategy avoiding the decomposition of a naked trifluoromethyl anion to difluorocarbene by a sterically very demanding organo-superbase without the help of a trifluoromethyl anion reservoir such as DMF is reported. The direct non-metallic trifluoromethylation of carbonyl compounds using fluoroform in the presence of t-Bu-P4 base afforded trifluoromethyl alcohols in high yields.

Diffraction peak profiles from spherical crystallites with lognormal size distribution

Abstract: An efficient and accurate method to evaluate the theoretical diffraction peak profiles from spherical crystallites with lognormal size distribution (SLN profile) is presented. Precise results can be obtained typically by an eight-term numerical integral for any values of the parameters, by applying an appropriate substitution of the variable to the integral formula. The calculated SLN profiles have been verified by comparison with those calculated by inverse Fourier transform from the exact analytical solution of the Fourier-transformed SLN profile. It has been found that the shape of the SLN profile strongly depends on the variance of size distribution. When the logarithmic standard deviation ω of the size distribution is close to 0.76, the SLN profile becomes close to a Lorentzian profile, and `super-Lorentzian' profiles are predicted for larger values of ω, as has been concluded by Popa & Balzar [J. Appl. Cryst. (2002), 35, 338–346]. The intrinsic diffraction peak profiles of an SiC powder sample obtained by deconvolution of the instrumental function have certainly shown `super-Lorentzian' line profiles, and they are well reproduced by the SLN profile for the value ω = 0.93.