This paper described the optical properties of CdSe and CdSe/CdS nanoparticles, synthesized by the microemulsion method followed by refluxing in toluene/methanol (60:1). Both optical spectroscopy and structural characterization (XPS, XRD, and HRTEM) suggested the core/shell structure of CdSe/CdS samples. Most notable in this work was that capping CdSe nanoparticles with CdS materials yielded a ...

We investigate theoretically and compare optical properties of wurtzite and zinc-blende GaN/AlN quantum dots with heights from 1.5 to 4.5 nm. The quantum dot size corresponds to the strong quantum confinement regime. It has been established that the built-in piezoelectric field at the GaN/AlN interface governs optical properties of wurtzite quantum dots while having a small effect on zinc-blend...

Based on the dielectric continuum model and transfer-matrix method, the completing polar optical phonon states in a wurtzite GaN-based superlattice (SLs) with arbitrary-layer complex bases are investigated. It is proved that 2 types of phonon modes probably exist in a wurtzite nitride SL with n-layer complex bases. The analytical phonon states of these modes and their dispersive equations in th...

Large ('1000 atoms) supercell valence force-field simulations are used to investigate the nearest-neighbor bond-length distribution in relaxed tetrahedral ~zinc blende and wurtzite! and octahedral ~rocksalt! Ga12xInxN alloys. We find that, due to the rigidity of the octahedron, the distribution of each anion-cation bond length in rocksalt alloys has two contributions: unrelaxed bonds and relaxe...

Modern quasiparticle calculations based on hybrid functionals and the GW approximation or a transition-state approach are used to predict natural band discontinuities between wurtzite and zinc-blende polytypes of AlN, GaN, and InN by two alignment methods, a modified Tersoff method for the branch-point energy and the Shockley-Anderson model aligning electrostatic potentials. We find a type-I he...

   Zinc oxide (ZnO) is the most common and widely utilized nanomaterial for biological applications due to their unique characteristics, such as biocompatibility, biosafety and antimicrobial along with thermal stability and mechanical strength. Magnesium (Cu) is considered as a significant dopant for ZnO due to their almost similar ionic radii and their role in biological activitie...

Selective area epitaxy constitutes a mainstream method to obtain reproducible nanomaterials. As counterpart, self-assembly allows their growth without costly substrate preparation, with the drawback of uncontrolled positioning. We propose mixed approach in which is limited reduced regions on patterned silicon substrate. While nanowires grow wide distribution diameters, we note mostly binary occ...

Ti-doped ZnO (TZO) and Bi2O3 thin films were designed deposited by magnetron sputtering successively on ITO glass substrate to form a ZnO/Bi2O3 (TZO/Bi2O3) heterojunction. Microstructure photoelectric properties of TZO, Bi2O3, TZO/Bi2O3 tested characterized. The results showed that TZO film with hexagonal wurtzite structure was preferentially grown along the crystal plane (002), had good crysta...

In this paper, the fabrication of ZnO tetrapod was investigated. It synthesized by thermal oxidation technique using metal zinc powder mixed with oxidizing agents such as hydrogen peroxide (H2O2) and ammonium persulfate ((NH4)2S2O8). The furnace heating temperature reached at 1000 °C in air. average diameter length a leg for mixture H2O2 from SEM were 45.3 nm 1.57 μm, respectively. oxygen vacan...