An ab initio pseudopotential method based on density functional theory, generalized gradient corrections to exchange and correlation, and projector-augmented waves is used to investigate structural, energetical, electronic, and optical properties of MgO, ZnO, and CdO in rocksalt, cesium chloride, zinc blende, and wurtzite structure. In the case of MgO we also examine the nickel arsenide structu...

The correlation between structural and optical properties of nanocrystalline ZnO synthesized by the citrate precursor method has been investigated. The Rietveld refinement of X-ray diffraction pattern confirms the P63mc space group and formation of single phase hexagonal wurtzite structure with presence of tensile strain at the lattice site. The presence of Raman active optical phonon mode at 4...

First principles calculations of L3 XANES/ELNES of GaN and InN with both wurtzite and zinc-blende structures have been made using OLCAO (orthogonalized linear combinations of atomic orbitals) method. Supercells with more than 100 atoms were employed. A core-hole was rigorously included in the calculation, and the photo absorption cross section (PACS) between the initial and final states was com...

Formation energies, equilibrium geometries, and elastic properties of ordered InxGa12xN structures have been calculated employing density funcional theory. Based on these results, limits and accuracy of several valence force field ~VFF! models are compared. While these empirical models have been shown to work reasonably well to describe zincblende III/V semiconductors we find significant deviat...

We present results of an ab initio study of the nitrogen antisite defect in GaN and AlN. We show that the neutral antisite in zinc-blende structure exhibits metastable behaviour similar to the arsenic antisite in GaAs, but in the wurtzite structure the phenomenon does not exist. A new discovery is that the negative charge states of the nitrogen antisite are stabilized by the large band gap. In ...

Here we investigate the feasibility of silver as seed-particle material to synthesize GaAs nanowires and show that both crystal phase and growth direction can be controlled by choice of substrate orientation. A (111)B substrate orientation can be used to form vertically aligned wurtzite GaAs nanowires and a (100) substrate orientation to form vertically aligned zinc blende GaAs nanowires. A 45-...

Hierarchical wurtzite ZnS architectures assembled from nanosheets and nanorods, such as branched flowers and fluffy solid and hollow spheres, have been synthesized by a facile, template-free, low-temperature solution route. The growth of wurtzite ZnS nanostructures at temperatures as low as 4 ◦C without any organic additives has been realized by the slow reaction between Zn(NH3) 2+ 4 and thioac...

Wurtzite CdxZn1 xO epilayers with cadmium concentrations ranging from x = 0.02 to 0.30 were investigated using photoluminescence, transmission/reflection spectroscopy, and atomic force microscopy. The CdxZn1 xO photoluminescence peak was found to shift through the visible region from 421 (2.95 eV) to 619 nm (2.0 eV) as the cadmium concentration was increased from 2% to 30%. An additional broad ...

The present work explores the electrical transport and infrared (IR) photoresponse properties of InN nanorods (NRs)/n-Si heterojunction grown by plasma-assisted molecular beam epitaxy. Single-crystalline wurtzite structure of InN NRs is verified by the X-ray diffraction and transmission electron microscopy. Raman measurements show that these wurtzite InN NRs have sharp peaks E2(high) at 490.2 c...

ZnO nanorods with diameter 90-100 nm range (tip diameter~15 nm) and length of about 2 μm have been prepared using microwave irradiation technique. X-ray diffraction (XRD) and transmission electron microscopy (TEM) results indicate that the nanorods have single phase nature with wurtzite structure and preferentially grow along [0001] direction. Raman spectrum shows the mode E2 high at 439 cm −1 ...