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Wurtzite crystal structure
About: Wurtzite crystal structure is a research topic. Over the lifetime, 18973 publications have been published within this topic receiving 478336 citations.
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TL;DR: In this paper, the authors derived the effective mass Hamiltonian for wurtzite semiconductors, including the strain effects, using the k-ensuremath{\cdot}p perturbation method, which is then checked with that derived using an invariant method based on the Pikus-Bir model.
Abstract: We derive the effective-mass Hamiltonian for wurtzite semiconductors, including the strain effects. This Hamiltonian provides a theoretical groundwork for calculating the electronic band structures and optical constants of bulk and quantum-well wurtzite semiconductors. We apply Kane's model to derive the band-edge energies and the optical momentum-matrix elements for strained wurtzite semiconductors. We then use the k\ensuremath{\cdot}p perturbation method to derive the effective-mass Hamiltonian, which is then checked with that derived using an invariant method based on the Pikus-Bir model. We obtain the band structure ${\mathit{A}}_{\mathit{i}}$ parameters in the group theoretical model explicitly in terms of the momentum-matrix elements. We also find the proper definitions of the important physical quantities used in both models and present analytical expressions for the valence-band dispersions, the effective masses, and the interband optical-transition momentum-matrix elements near the band edges, taking into account the strain effects. \textcopyright{} 1996 The American Physical Society.
924 citations
TL;DR: In this article, a comprehensive study of phonon lifetimes and thermal conductivity for 33 zincblende- and wurtzite compounds using linearized phonon Boltzmann equation and first-principles anharmonic phonon calculations is presented.
Abstract: A collaboration of researchers from Japan and France present a comprehensive study of phonon lifetimes and thermal conductivity for 33 zincblende- and wurtzite compounds using linearized phonon Boltzmann equation and first-principles anharmonic phonon calculations. The software that the authors created for this study will be released as an open source package and should be of help in the search of new materials for thermoelectric applications.
921 citations
TL;DR: In this article, the effects of the competition between the long-range electrostatic forces and the short-range forces due to anisotropy in the interatomic force constants on the vibrational spectrum has been included.
Abstract: First-order Raman scattering from BeO, ZnO, ZnS, and CdS, all having the wurtzite structure (${C}_{6v}$), has been investigated. A discussion of the effects of the competition between the long-range electrostatic forces and the short-range forces due to anisotropy in the interatomic force constants on the vibrational spectrum has been included. A series of scattering diagrams are presented showing the geometrical arrangements necessary to observe all the $k=0$ phonons for this type of crystal structure. In BeO the ${E}_{2}$ mode was resolved from the transverse modes for the first time. The assignments of the ${E}_{2}$ modes in ZnS differ from previous investigations. From absolute intensity measurements, electro-optic coefficients for BeO, ZnO, and CdS were determined.
886 citations
TL;DR: Duan and Lieber as mentioned in this paper reported the bulk synthesis of single crystalline GaN-nanowires by laser ablation of a composite target of GaN and acatalytic metal, which generated liquid nanoclusters that serve as reactivesites confining and directing the growth of crystalline nanowires.
Abstract: Xiangfeng Duan and Charles M. Lieber*Department of Chemistry and Chemical BiologyHarVard UniVersity, Cambridge, Massachusetts 02138ReceiVed October 18, 1999Herein we report the bulk synthesis of single crystalline GaNnanowires. Laser ablation of a composite target of GaN and acatalytic metal generates liquid nanoclusters that serve as reactivesites confining and directing the growth of crystalline nanowires.Field emission scanning electron microscopy (FE-SEM) showsthat the product primarily consists of wire-like structures. PowderX-ray diffraction (PXRD) analyses of a bulk nanowire samplecan be indexed to the GaN wurtzite structure, and indicate >95%phase purity. Transmission electron microscopy (TEM), conver-gent beam electron diffraction (CBED), and energy-dispersiveX-ray fluorescence (EDX) analyses of individual nanowires showthat they are GaN single crystals with a [100] growth direction.Nanostructured GaN materials have attracted extensive interestover the past decade due to their significant potential foroptoelectronics.
781 citations
TL;DR: In this article, the formation of nearly monodisperse CdTe nanocrystals was studied, and the ligand effects on the monomers were found to play a more important role than ligand effect on the nanocrystal and the bonding strength and steric effects of ligands dramatically affect the reactivity of monomers and are considered as contributors to the activity coefficients of monomer.
Abstract: The formation of nearly monodisperse CdTe nanocrystalsdots (either zinc blende or wurtzite crystal structure), rods, and tetrapodsin a noncoordinating solvent was studied Several strong ligand effects were observed, and the ligand effects on the monomers were found to play a more important role than the ligand effects on the nanocrystals Experimental results suggest that, instead of monomer concentrations, monomer activities is a more relevant term for understanding the formation of nanocrystals because strong ligands always exist in the reaction solutions The bonding strength and the steric effects of ligands dramatically affect the reactivity of monomers and are considered as contributors to the activity coefficients of monomers The overall optical properties of the as-prepared CdTe nanocrystals are better than those reported in the literature and comparable to the standard CdSe nanocrystal system The configuration of the hydrocarbon chains of the ligands on the surface of each nanocrystal also pla
753 citations