The pressure-induced phase transition in silicon carbide is studied using a constant-pressure ab initio technique. The reversible transition between the zinc-blende structure and the rock-salt structure is successfully reproduced through the simulation. The transformation mechanism at the atomistic level is characterized, and it is found that the transition is based on a tetragonal and an ortho...

We demonstrate the results of two-dimensional (2-D) hydrodynamic simulations of one-finger power heterojunction bipolar transistors (HBTs) on GaAs. An overview of the physical models used and comparisons with experimental data are given. We present models for the thermal conductivity and the specific heat applicable to all relevant diamond and zinc-blende structure semiconductors. They are expr...

Lattice constant, cohesive energy, direct band gap and valence band width had been calculated for grey tin by using ( CNDO-LUC ) method, then we had been making a comparison with experimental and other workers results for ( C, Si, Ge and Sn ) with zinc-blende structure in order to study the efficiency of this method. The results had showed that this method is good for lattice constant and bad f...

Hierarchical nanowires (HNWs) exhibit unique properties and have wide applications, while often suffering from imperfect structure. Herein, we report a facile strategy toward ultrathin CdS HNWs with monocrystal structure, where a continuous-wave (CW) Nd:YAG laser is employed to irradiate an oleic acid (OA) solution containing precursors and a light absorber. The high heating rate and large temp...

In this study, cubic GaN epitaxial "lms are grown on a 23miscut GaAs(0 0 1) substrate by hydride vapor-phase epitaxy reactor with a low-temperature GaN bu!er layer before the growth of the GaN epitaxy "lm. X-ray di!raction spectra reveal that the epitaxial "lm contains most of the zinc-blende GaN with a few percent of wurtzite GaN also embedded in the "lm. The crystalline coherence length of th...

We reveal the existence of two different crystalline phases, i.e., the metastable rock salt and the equilibrium zinc blende phase within the CdS-shell of PbS/CdS core/shell nanocrystals formed by cationic exchange. The chemical composition profile of the core/shell nanocrystals with different dimensions is determined by means of anomalous small-angle X-ray scattering with subnanometer resolutio...

Half-Heusler compounds XYZ, also called semi-Heusler compounds, crystallize in the MgAgAs structure, in the space group F 4̄3m. We report a systematic examination of band gaps and the nature (covalent or ionic) of bonding in semiconducting 8and 18electron half-Heusler compounds through first-principles density functional calculations. We find the most appropriate description of these compounds f...

We report the fabrication of quantum wells in ZnO nanowires (NWs) by a crystal phase engineering approach. Basal plane stacking faults (BSFs) in the wurtzite structure can be considered as a minimal segment of zinc blende. Due to the existing band offsets at the wurtzite (WZ)/zinc blende (ZB) material interface, incorporation of a high density of BSFs into ZnO NWs results in type II band alignm...

We present ab initio and k·p calculations of the spin texture on the Fermi surface of tensile-strained HgTe, which is obtained by stretching the zinc-blende lattice along the (111) axis. Tensile-strained HgTe is a semimetal with pointlike accidental degeneracies between a mirror symmetry protected twofold degenerate band and two nondegenerate bands near the Fermi level. The Fermi surface consis...