Gallium nitride (GaN) nanopowder used as a blue fluorescent material was synthesized by using a direct current (DC) non-transferred arc plasma. Gallium nitrate hydrate (Ga(NO₃)₃∙xH₂O) was used as a raw material and NH₃ gas was used as a nitridation source. Additionally, melamine (C₃H₆N₆) powder was injected into the plasma flame to prevent the oxidation of gallium to gallium oxide (Ga₂O₃). Argo...

In recent years there has been considerable interest in the structures, energies and thermodynamics of(GaN)4 clusters and it is the subject of many experimental and theoretical studies because of theirfundamental importance in chemical and physical process. All calculation of this study is carried outby Gaussian 98. Geometry optimization for (GaN)4 nanocluster are be fulfilled at B3LYP, B1LYPan...

This work addresses the enormous efficiency and linearity potential of optimized AlGaN/GaN high-electron mobility transistors (HEMT) in conventional Doherty linear base-station amplifiers at 2.7 GHz. Supported by physical device simulation, the work further elaborates on the use of AlGaN/GaN HEMTs in high-speed current-switch-mode classD (CMCD)/class-S MMICs for data rates of up to 8 Gbit/s equ...

The use of wide bandgap materials for broadcast telecommunication and defense systems allow high power, high efficiency and high integration levels of active devices thanks to their microwave electrical performances. GaN based devices have also demonstrated great potential for high frequency linear low noise applications. However, low frequency noise (LFN) performances characteristics are still...

The thermal management challenge posed by gallium nitride (GaN) high-electron-mobility transistor (HEMT) technology has received much attention in the past decade. The peak amplification power density of these devices is limited by heat transfer at the device, substrate, package, and system levels. Thermal resistances within micrometers of the transistor junction can limit efficient heat spread...

In this paper, a design method of two-dimensional (2-D) orthogonal symmetric wavelets is proposed by using a lattice structure for multi-dimensional (M-D) linear-phase paraunitary filter banks (LPPUFB), which the authors have proposed as a previous work and then modified by Lu Gan et al. The derivation process for the constraints on the second-order vanishing moments is shown and some design ex...

Gallium nitride high electron mobility transistors (GaN HEMTs) were developed for millimeter-wave high power amplifier applications. The device with a gate length of 80 nm and an InAlN barrier layer exhibited high drain current of more than 1.2 A/mm and high breakdown voltage of 73V. A cut-off frequency fT of 113GHz and maximum oscillation frequency fmax of 230GHz were achieved. The output powe...

Cavity-enhanced single-photon emission in the blue spectral region was measured from single InGaN/GaN quantum dots. The low-Q microcavities used were characterized using micro-reflectance spectroscopy where the source was the enhanced blue output from a photonic crystal fibre. Micro-photoluminescence was observed from several cavities and found to be ~10 times stronger than typical InGaN quantu...

in this work we use density functional theory based on the ultra-soft pseudo-potential to calculate thestructural, mechanical and thermal properties of narrow single walled bn, aln and gan nanotubes.the electron-electron interactions were expressed within the local density approximation (lda). wehave also obtained the phonon dispersion and elastic constants of these nanotubes using the densityf...

We present ab-initio local density FLAPW calculations on non–reactive N– terminated [001] ordered GaN/Ag and GaN/Au interfaces and compare the results (such as metal induced gap states and Schottky barrier heights) with those obtained for GaN/Al, in order to understand the dependence of the relevant electronic properties on the deposited metal. Our results show that the density of gap states is...