We have performed the Density Functional Tight Binding (DFTB) study on the structural properties of Zinc Oxide Nanoparticles (NP), focusing on the effects induced by the surfaces and quantum size effect. Effects of surface relaxation and surface stress which is absent in atomistic model are taken carefully into account. The studying Nanoparticle size range up to 2.3nm. We illustrated the struct...

UNLABELLED CdS nanoparticles have a great potential for application in chemical research, bioscience and medicine. The aim of this study was to develop an efficient and environmentally-friendly method of plant-based biosynthesis of CdS quantum dots using hairy root culture of Linaria maroccana L. By incubating Linaria root extract with inorganic cadmium sulfate and sodium sulfide we synthesized...

Wurtzite CuInS2 nanoleaves were synthesized by Cu1.94S-assisted growth. By observing the evolution of structures and phases during the growth process, Cu1.94S nanocrystals were found to be formed after uninterrupted oxidation and sulfidation of copper nanoparticles at the early stage, serving as catalysts to introduce the Cu and In species into CuInS2 nanoleaves growth for inherent property of ...

The structural, vibrational, and electronic properties of GaAs nanowires have been studied in the metastable wurtzite phase via Resonant Raman spectroscopy and synchrotron X-ray diffraction measurements in diamond anvil cells under hydrostatic conditions between 0 and 23 GPa. The direct band gap E0 and the crystal field split-off gap E0 + Δ of wurtzite GaAs increase with pressure and their valu...

We derive analytically the interface and confined polar optical-phonon modes for spherical quantum dots with wurtzite crystal structure. While the frequency of confined optical phonons in zincblende nanocrystals is equal to that of the bulk crystal phonons, the confined polar optical phonons in wurtzite nanocrystals are shown to have a discrete spectrum of frequencies different from those in bu...

In this work, SiO2/ZnO composite hollow sub-micron fibers were fabricated by a facile single capillary electrospinning technique followed by calcination, using tetraethyl orthosilicate (TEOS), polyvinylpyrrolidone (PVP) and ZnO nanoparticles as raw materials. The characterization results of the scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) a...

Polar optical-phonon modes are derived analytically for spheroidal quantum dots with wurtzite crystal structure. The developed theory is applied to freestanding spheroidal ZnO quantum dots and to spheroidal ZnO quantum dots embedded into a MgZnO crystal. The wurtzite (anisotropic) quantum dots are shown to have strongly different polar optical-phonon modes in comparison with zincblende (isotrop...

We derive within the dielectric-continuum model an integral equation that defines interface and confined polar optical-phonon modes in nanocrystals with a wurtzite crystal structure. It is demonstrated theoretically that, while the frequency of confined polar optical phonons in zinc-blende nanocrystals is equal to that of the bulk crystal phonons, the confined polar optical phonons in wurtzite ...

Kesterite Cu2ZnSn(SxSe1−x)4 has tunable band-gap values in the range 1 to 1.5 eV depending upon Sulphur/Selenium stoichiometry. We analyze proposed tandem configuration of kesterite absorber family using SCAPS-1D for device performance. Pure sulphide Cu2ZnSnS4 (CZTS) bandgap is utilized as top cell and a sulpho-selenide (CZTSSe) 1.1 bottom stacked configuration. utilize script file capability S...

Title of Dissertation: DEVELOPMENT OF SELF-ASSEMBLED ZnO NANOSTRUCTURES IN DIBLOCK COPOLYMERS ON LARGE AREA Si WAFERS AND GAS SENSOR APPLICATIONS Hasina Afroz Ali, Doctor of Philosophy, 2008 Dissertation Directed By: Agis A. Iliadis Department of Electrical and Computer Engineering ZnO nanoparticles with improved optical properties and increased surface areas have the potential for advanced opt...