Raman scattering study of zinc blende and wurtzite zns. Althoughthe termzinc blende originatedin compoundssuchas zns, whichcould be in cubic or hexagonal phase, it has been used ubiquitously for compound. By increasing the thiourea amount to the ratio of 1. Although the zno usually has the wurtzite structure,21 it is known that the zincblende structure exists as a meta stable state. Powder xray diffraction xrd patterns of znszno qds produced after thermal annealing. Zns nanowires with wurtzite polytype modulated structure. Supplementary material 1 powder xray diffraction xrd. The bonding is less ionic than in rock salt structure compounds.
Size and morphologydependent optical properties of zns. Because of these reasons, the nanocrystal quantum dots display unique electronic and optical properties including size tunable light emission, simultaneous excitation of. The stokes method for the determination of pyrite and. The substrate temperature was varied in the range of 100c to 400c. The effect of polyvinyl alcohol concentration on the zns particle formation is studied, and zns nanocrystals smaller than the bohr exciton radius have been prepared using the capping agent polyvinyl alcohol. Hydrothermal cation exchange enabled gradual evolution of. In addition to p zinc sulfide zincblende or sphalerite and a zinc sulfide. Files are available under licenses specified on their description page. Synthesis and characterization of chromium doped zinc sulfide.
Zns crystalline structure of the blende phase a and wurtzite b. Catalytic growth of clusters of wurtzite zns nanorods. Latexmediated synthesis of zns green synthesis approach. The phase transformation of cuins2 from chalcopyrite to wurtzite. The surface morphology and microstructure studies revealed that the hierarchical spheres were consisted of many wellaligned nanosheets with width 10 nm and length about 50 100 nm. Download amc data view text file download cif data view text file download diffraction data view text file. Diffusion behavior and microstructural properties of the. Those marked with black squares can be indexed to hexagonal wurtzite zno jcpds file no. Structural and optical properties of zns thin films deposited. To the best of our knowledge, this is the first report that controls the phase transformation of cuins2 from chalcopyrite to wurtzite by adjusting the ph value of the reaction solution.
The photoluminescence at 550nm became increasingly. For example, nilsen7 estimated the frequency of the lamode at x point in the brillouin zone bz to be 110 cm. It will be apparent that the lower limit of determination of structure of the zns polytypes would be on atomic dimensions and thus impractical for mineralogical purposes. The presence of a solid window at the entrance aperture of an airborne flir can degrade the signaltonoise ratio as a result of a the reduction in target signalcaused by the absorption of radiation by the window and b the loss in system detectivity caused by additional quantum noise generated by windowemitted photons. Where d is the diameter of particle, k is a geometric factor taken to be 1. Morphologytuned wurtzitetype zns nanobelts geosciences. These peaks correlate well with hexagonal zns wurtzite structure standard pattern of jcpds card number 800007. Both on sight as from the line profile, it is clear that one end of the nanorods has a higher intensity.
Thus, oxides do not usually have the zinc blende structure zno, not included in table 1. Zinc blende versus wurtzite zns nanoparticles repositori uji. Each spectrum corresponds to the regions shown in the element maps in figure 3. Raman scattering study of zinc blende and wurtzite zns article pdf available in journal of applied physics 10612. Catalytic growth of clusters of wurtzite zns nanorods through codeposition of zns and zn on au. The chemical prototype is conventionally given as zns, although mineral wurtzite is a multicomponent alloy compound. Those marked with can be indexed to hexagonal wurtzite zno jcpds file no.
Ethylenediaminemediated wurtzite phase formation in zns. The orange line indicates the wurtzite zns diffraction pattern jcpds card 010843995. Pdf raman scattering study of zinc blende and wurtzite zns. The diffraction peaks are in agreement with earlier reported studies 45, 46. We have conducted an experimental and theoretical study on first and secondorder raman scattering of zinc blende and wurtzite zns. The oxidation of phase pure zns in the wurtzite and sphalerite modification upon heating in an air flow has been studied by simultaneous thermogravimetry. C45, 18671870 u parameters for the wurtzite structure of zns and zno using. The optical properties of the semiconductor zns in wurtzite structures are considerably enhanced, but the lack of structural stability. Cdsezns in benzene, under same conditions, were studied. The zno wurtzitezns blende interface goes from continuous and dense, at short tc, to discontinuous and porous at long tc, indicating that zns. Diffusion behavior and microstructural properties of the cbd. Each zone provides an lba range that must be written sequentially and if written again must be explicitly reset.
The samples, prepared by a surfactant tween20assisted liquidliquid reaction at ph 6, consist. But in this present work the xrd pattern is in good agreement figure 1. The wurtzite crystal structure, named after the mineral wurtzite, is a crystal structure for various binary compounds. Each unit cell has 4 formula units of wurtzite structure. The polytype modulated zns nanowires show a strong blue. Polytypes 2h, 4h, 6h, 8h, 10h, 15r, 18r, and 21r are known.
The wurtzite structure has a hexagonal unit cell and thus two lattice constants, c. This structure is a member of the hexagonal crystal system and consists of tetrahedrally coordinated zinc and sulfur atoms that are stacked in an ababababab pattern. The stokes method for the determination of pyrite and marcasite. The structural changes of cubic zns czns nanocrystals ncs doped with 0. The diffusion behavior and microstructural properties of the cbdznscuin,gase 2 cigs interface of highefficiency cdfree cigs thin film solar cells with efficiencies exceeding 17 % have been investigated using energy dispersive xray spectroscopy edx and transmission electron microscopy tem. A novel polytype modulated 1d structure has been grown in zns nanowires via intermittent laser ablationcatalytic growth. Band gaps and quasiparticle energy calculations on zno, zns. The structural and the photoelectrochemical properties of znozns. The phase transformation of cuins2 from chalcopyrite to. The zns nanoparticles were prepared by a microwaveassisted solvothermal method, and the phase structure and optical properties along with the growth process of zns nanoparticles were studied. Stop the rotation and spin the structure so you can see a a view down the hexagonal layers and b a side on view of the layers. All structured data from the file and property namespaces is available under the creative commons cc0 license.
The diffusion behavior and microstructural properties of the cbd zns cuin,gase 2 cigs interface of highefficiency cdfree cigs thin film solar cells with efficiencies exceeding 17 % have been investigated using energy dispersive xray spectroscopy edx and transmission electron microscopy tem. Zns is one of the most important semiconducting materials, and this paper discusses the wet chemical synthesis of zns nanoparticles in cubic and hexagonal structures. Cbdzns thin layers are found to grow with small polycrystalline grains that consist. Tem micrographs and size distribution using dls of the zns nanoparticles prepared in. Jul 17, 2003 a novel polytype modulated 1d structure has been grown in zns nanowires via intermittent laser ablationcatalytic growth.
Pdf synthesis of wurtzite zns nanocrystals at low temperature. Zns modification the hexagonal hightemperature variant. Dresselhaus effect in bulk wurtzite materials article pdf available in applied physics letters 918. Xray diffraction and raman spectroscopy analysis confirmed the enmediated phase transformation zinc blende to wurtzite of zns. The xrd images show that nearly all of the peaks agree with the zns wurtzite structure jcpds 361450, except for a small peak at 32. Zinc sulfide zns is a unique compound that forms two types of crystalline structures. However, certain properties pertaining to zns are unique and advantageous compared to zno. Synthesis of zns nanocrystals with controllable structure and.
Synthesis and characterization of chromium doped zinc. Zns modification the hexagonal high temperature variant. Based on the calculated phonon band structure, phonon density of states, and symmetry selection rules, we have clearly identified for the first time the origins of these vibration modes in the secondorder raman spectra from these two polymorphs. Structural phase transformations in annealed cubic zns. The oxidation of wurtzite starts at higher temperature, zno is formed without any detectable side or. Mgdoped zns hierarchical spheres have been synthesized via hydrothermal method using mixed solvents of ethylenediamine and di water without any surfaceactive agent. Hydrothermal cation exchange enabled gradual evolution of au. This page was last edited on 7 january 2019, at 07.
Optical properties of synthesized nanoparticles zns using. Structural biochemistryformulas and structures wikibooks. Structural and thermal studies of zns and cds nanoparticles. It may be described as half the tetrahedral holes in a hcp of s being occupied by zn. The range of nonstoichiometry in minerals of the system znscds studied is in the order of 2. The influence of tetrabutylammonium hydroxide on the phase composition cubic zinc blende versus hexagonal wurtzite of zns nanoparticles was studied. Synthesis of zns nanocrystals with controllable structure. Zns single crystals consist of 96 98% of zincblende and only 24% of.
Its crystal structure is called the wurtzite crystal structure, to which it lends its name. Pdf nanocrystallites of wurtzite hexagonal zns have been successfully synthesized without using any capping agent by simple chemical precipitation. Znozns qds interfacial heterostructure for drug and food. We conclude that there is not a complete solidsolution between wurtzite and greenockite in the temperature range studied owing to a phase transition in zns and a change in the structure type. Among those zns, which is an important wide band gap semiconductor and can have two different crystal structures zinc blende and wurtzite, both of which have. Diamond structure same as zinc blende, but with only one element coordination 4 connectivity corner sharing tetrahedra. Xrd pattern of pure and cr doped zns nanoparticles. Eds spectra for wurtzite and zincblende a cds and b zns exchange products. Nvme zoned namespaces zns divides the logical address space of a namespace into zones.
Znspmma exhibits two broadened diffraction peaks from 2543 which may be due to overlapping of 100, 002, and 101 miller indices. Band gaps and quasiparticle energy calculations on zno. Absorption spectra for zns a and nanoparticles with. Pdf the influence of tetrabutylammonium hydroxide on the phase composition cubic zinc blende versus hexagonal wurtzite of zns. Rahdar 10 reported that the cr doped zns nanoparticles synthesized by coprecipi tation route was wurtzite hexagonal structure. The peak located at 278 cm 1 is the a 1 mode and the peak at 353 cm 1 is the lo mode of a 1 and e 1 symmetry. Also along shrinkage fractures in clayironstone concretions, of lowtemperature origin. All structured data from the file and property namespaces is available under the. Thermal oxidation of zns modifications sphalerite and wurtzite. Each unit cell has 4 formula units of zns structure.
In a and b, the spectrum for zincblende is shown on top and the spectrum for wurtzite is below. Replacing both types of atoms of the wurtzite structure with carbon atoms gives the hexagonal diamond, which is a slight modification of the cubic diamond structure found in nature in some meteorites. Among the family of iivi semiconductors, zns, cds and cdte are the foremost candidates because of their favorable electronic and optical properties for optoelectronic applications. Some compounds with the zinc blende structure are listed in table 1. Wurtzite is a zinc iron sulfide mineral zn,fes a less frequently encountered mineral form of sphalerite. Perovskite batio 3 perovskite pbtio 3 perovskite batio 3 2 catio 3 4.
Wurtzite has a hexagonal structure, while zincblende is cubic. Catalytic growth of clusters of wurtzite zns nanorods through. This work may provide a feasible reference for the simple and easy synthesis of different phasestructured iiiivi2 ternary semiconductor compounds. Each type of ion forms a hexagonal closedpacked lattice. Vapour grown zns and ain crystals of wurtzite structure are studied by transmission electron microscopy. The structural and optical properties of zns thin films were characterized with xray diffraction xrd, field emission scanning electron microscopy fesem, energy dispersive analysis of xrays and uvvisible. All spectra are normalized to the intensity of the s k.
Zinc sulfide zns thin films were deposited on glass substrates using radio frequency magnetron sputtering. U parameters for the wurtzite structure of zns and zno. Structural and optical properties of zns thin films. Molaei crystallite size of zns nanoparticles were calculated following the debye scherrers equation 7.
The usual high temperature wurtzite phase of zns was successfully obtained at low temperature 170 c in the presence of ethylenediamine en as the soft template. Structureselective synthesis of wurtzite and zincblende zns. Xray photoelectron spectroscopy xps showed that all the samples were sulfur deficient. If you do not see its contents the file may be temporarily unavailable at the journal website or you do not have a pdf plugin installed and enabled in your browser. Parallel fntergrowths between difierent polymorphs. Effect of polyvinyl alcohol concentration on the zns. The wurtzite structure consists of hexagonal closepacked arrays of zn and s atoms separated by a translation of about 0. A large number of ionic structures can be regarded as built of cp layers of anions.
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