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Relevant bibliographies by topics / Wurtzite crystal

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Academic literature on the topic 'Wurtzite crystal'

Author: Grafiati

Published: 6 September 2023

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Journal articles on the topic "Wurtzite crystal"

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Hostettler, M., and H. D. Flack. "Anti-wurtzite reoriented." Acta Crystallographica Section B Structural Science 59, no. 4 (July 25, 2003): 537–38. http://dx.doi.org/10.1107/s0108768103009467.

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Anti-wurtzite and wurtzite are shown to be the same crystal structure despite the claims of a recent paper describing the crystal structure of the mineral rambergite, Mn1−x Fe x S, x ≃ 0.05. The anti-wurtzite/wurtzite confusion is used as an illustration to help clarify the correct general approach to take in the treatment and presentation of achiral non-centrosymmetric crystal structures.

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Liu, Wu, Qiu Li, Gang Jin, and Wei Qiu. "Measurement of the Euler Angles of Wurtzitic ZnO by Raman Spectroscopy." Journal of Spectroscopy 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/6430540.

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A Raman spectroscopy-based step-by-step measuring method of Euler angles φ,θ,and ψ was presented for the wurtzitic crystal orientation on a microscopic scale. Based on the polarization selection rule and coordinate transformation theory, a series of analytic expressions for the Euler angle measurement using Raman spectroscopy were derived. Specific experimental measurement processes were presented, and the measurement of Raman tensor elements and Euler angles of the ZnO crystal were implemented. It is deduced that there is a trigonometric functional relationship between the intensity of each Raman bands of wurtzite crystal and Euler angle ψ, the polarization direction of incident light under different polarization configurations, which can be used to measure the Euler angles. The experimental results show that the proposed method can realize the measurement of Euler angles for wurtzite crystal effectively.

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Sink, Joseph, and Craig Pryor. "Empirical tight-binding parameters for wurtzite group III–V(non-nitride) and IV materials." AIP Advances 13, no. 2 (February 1, 2023): 025354. http://dx.doi.org/10.1063/5.0129007.

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Suitable tight-binding models for wurtzite III–V (non-nitride) and group-V materials are presently missing in the literature. Many commonly used nearest neighbor tight-binding models for cubic-zincblende semiconductors result in highly inaccurate band structures when transferred to hexagonal polytypes. Wurtzite parameters would be of use in modeling nanowires that primarily condense into either wurtzite or zincblende crystal phases. Nanowire growth has seen significant development over the last decade, and polytypic heterostructures are now able to be fabricated. We have produced a set of spds* tight-binding parameters to be used in the hexagonal-wurtzite crystal phase for non-nitride III–V and group V semiconductors. We confine our parameter space to remain in the vicinity of a well-established zincblende parameter set to ensure semi-transferability between the wurtzite and zincblende polytypes. Our wurtzite parameters, when combined with the existing zincblende parameters, enable modeling electronic structures of heterostructures containing both the wurtzite and zincblende crystal phases.

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Sana, Prabha, Shammi Verma, and M. M. Malik. "Optical and Structural Investigations of Manganese Doped ZnS/SiO2 Core-Shell Nanostructure." International Journal of Nanoscience 14, no. 03 (May 19, 2015): 1550006. http://dx.doi.org/10.1142/s0219581x15500064.

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The paper reports room temperature synthesis of wurtzite type manganese doped ZnS nanostructures via colloidal technique. The reaction procedure found to play an important role in the crystal growth of ZnS . Surface encapsulation of ZnS by silica ( SiO 2) provides effective approach for uniform coating, where 3-Mercaptopropyl Tri methoxysilane (MPS) has been used for silica source as a capping molecule. The obtained silica coated ZnS nanocrystals were well dispersed with hexagonal wurtzite structure of core-shell particles size of about 15 nm. Aggregation of these nanoparticles has been promoted to special shaped structures, which are crystals of 8H wurtzite with prominent pyramidal morphology with curved faces. Growth phenomena of this wurtzite polytype of homologous series 8H is based on screw dislocations and exhibited optimal photoluminescence (PL) spectra.

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Saleem, Samra, Ammara Maryam, Kaneez Fatima, Hadia Noor, Fatima Javed, and Muhammad Asghar. "Phase Control Growth of InAs Nanowires by Using Bi Surfactant." Coatings 12, no. 2 (February 15, 2022): 250. http://dx.doi.org/10.3390/coatings12020250.

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To realize practical applications of nanowire-based devices, it is critical, yet challenging, to control crystal structure growth of III-V semiconductor nanowires. Here, we demonstrate that controlled wurtzite and zincblende phases of InAs nanowires can be fabricated using bismuth (Bi) as a surfactant. For this purpose, catalyst free selective area epitaxial growth of InAs nanowires was performed using molecular beam epitaxy (MBE). During the growth, Bi was used which may act as a wetting agent influencing the surface energy at growth plane ends, promoting wurtzite crystal phase growth. For a demonstration, wurtzite and zincblende InAs nanowires were obtained with and without using Bi-flux. Photoluminescence spectroscopy (PL) analysis of the nanowires indicates a strong correlation between wurtzite phase and the Bi-flux. It is observed that the bandgap energy of wurtzite and zincblende nanowires are ∼0.50 eV and ∼0.42 eV, respectively, and agree well with theoretical estimated bandgap of corresponding InAs crystal phases. A blue shift in PL emission peak energy was found with decreasing nanowire diameter. The controlled wurtzite and zincblende crystal phase and its associated heterostructure growth of InAs nanowires on Si may open up new opportunities in bandgap engineering and related device applications integrated on Si. Furthermore, this work also illustrates that Bi as a surfactant could play a dynamic role in the growth mechanism of III-V compound semiconductors.

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Ross, Jennifer, Mike Rubin, and T. K. Gustafson. "Single crystal wurtzite GaN on (111) GaAs with AlN buffer layers grown by reactive magnetron sputter deposition." Journal of Materials Research 8, no. 10 (October 1993): 2613–16. http://dx.doi.org/10.1557/jmr.1993.2613.

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We report the growth conditions necessary for highly oriented wurtzite GaN films on (111) GaAs, and single crystal GaN films on (111) GaAs using AlN buffer layers. The GaN films and AlN buffers are grown using rf reactive magnetron sputter deposition. Oriented basal plane wurtzite GaN is obtained on (111) GaAs at temperatures between 550 and 620 °C. However, using a high temperature 200 Å AlN buffer layer epitaxial GaN is produced. Crystal structure and quality are measured using x-ray diffraction (XRD), reflection electron diffraction (RED), and a scanning electron microscope (SEM). This is the first report of single crystal wurtzite GaN on (111) GaAs using AlN buffer layers by any growth technique. Simple AlN/GaN heterostructures grown by rf reactive sputter deposition on (111) GaAs are also demonstrated.

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Ma, Yan, Jikang Jian, Rong Wu, Yanfei Sun, and Jin Li. "Preparation of CdTe nanostructures with different crystal structures and morphologies." Powder Diffraction 26, S1 (December 2011): S47—S50. http://dx.doi.org/10.1154/1.3662023.

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CdTe nanorods and various branched nanostructures with different crystal structures were have successfully prepared via the catalyst-assisted vacuum thermal evaporation (CVTE) technique using various experimental parameters. SEM and XRD studies were carried out on the as-prepared CdTe nanostructures. The results show that the morphologies and crystal structures of the products were strongly influenced by the growth conditions and the mole ratios of Bi and CdTe. In the high mole ratio (0.08:1) of Bi and CdTe, CdTe branched nanostructures of CdTe were obtained, while nanorods of CdTe were formed at a lower mole ratio of 0.05:1. The crystal structure of products is either Zinc blende or a two-phase mixture of zinc blende and wurtzite. The content of the wurtzite phase were found to increase with increasing growth temperature. Our results also reveal that high growth temperature tends to form the wurtzite phase, and stacking faults may exist in materials grown in higher temperatures. These nanostructures grow following the vapor–liquid–solid (VLS) mechanism.

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Volcheck, V. S., M. S. Baranava, and V. R. Stempitsky. "Thermal conductivity of wurtzite gallium nitride." Proceedings of the National Academy of Sciences of Belarus, Physical-Technical Series 67, no. 3 (October 8, 2022): 285–97. http://dx.doi.org/10.29235/1561-8358-2022-67-3-285-297.

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This paper reviews the theoretical and experimental works concerning one of the most important parameters of wurtzite gallium nitride – thermal conductivity. Since the heat in gallium nitride is transported almost exclusively by phonons, its thermal conductivity has a temperature behavior typical of most nonmetallic crystals: the thermal conductivity increases proportionally to the third power of temperature at lower temperatures, reaches its maximum at approximately 1/20 of the Debye temperature and decreases proportionally to temperature at higher temperatures. It is shown that the thermal conductivity of gallium nitride (depending on fabrication process, crystallographic direction, concentration of impurity and other defects, isotopical purity) varies significantly, emphasizing the importance of determining this parameter for the samples that closely resemble those being used in specific applications. For isotopically pure undoped wurtzite gallium nitride, the thermal conductivity at room temperature has been estimated as high as 5.4 W/(cm·K). The maximum room temperature value measured for bulkshaped samples of single crystal gallium nitride has been 2.79 W/(cm·K).

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Pavlov, Alexander, Alexey Mozharov, Yury Berdnikov, Camille Barbier, Jean-Christophe Harmand, Maria Tchernycheva, Roman Polozkov, and Ivan Mukhin. "DFT analysis of crystal polarity on graphene surface." Journal of Physics: Conference Series 2015, no. 1 (November 1, 2021): 012105. http://dx.doi.org/10.1088/1742-6596/2015/1/012105.

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Abstract We report an ab-initio study of the preferred polarity for wurtzite GaN nanostructures on virtual graphene substrates. By means of the density functional theory analysis we show that N-polar nanostructures on graphene are energetically favorable in comparison to Ga-polar. These finding are in agreement with experimentally observed N-polarity of wurtzite GaN nanowires grown on graphene substrate. We believe that the revealed polarity preference is of importance for piezoelectric and optoelectronic device design.

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Chen, Chunlin, Deqiang Yin, Takeharu Kato, Takashi Taniguchi, Kenji Watanabe, Xiuliang Ma, Hengqiang Ye, and Yuichi Ikuhara. "Stabilizing the metastable superhard material wurtzite boron nitride by three-dimensional networks of planar defects." Proceedings of the National Academy of Sciences 116, no. 23 (May 17, 2019): 11181–86. http://dx.doi.org/10.1073/pnas.1902820116.

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Wurtzite boron nitride (w-BN) is a metastable superhard material that is a high-pressure polymorph of BN. Clarifying how the metastable high-pressure material can be stabilized at atmospheric pressure is a challenging issue of fundamental scientific importance and promising technological value. Here, we fabricate millimeter-size w-BN bulk crystals via the hexagonal-to-wurtzite phase transformation at high pressure and high temperature. By combining transmission electron microscopy and ab initio molecular dynamics simulations, we reveal a stabilization mechanism for w-BN, i.e., the metastable high-pressure phase can be stabilized by 3D networks of planar defects which are constructed by a high density of intersecting (0001) stacking faults and {101¯0} inversion domain boundaries. The 3D networks of planar defects segment the w-BN bulk crystal into numerous nanometer-size prismatic domains with the reverse crystallographic polarities. Our findings unambiguously demonstrate the retarding effect of crystal defects on the phase transformations of metastable materials, which is in contrast to the common knowledge that the crystal defects in materials will facilitate the occurrence of phase transformations.

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Dissertations / Theses on the topic "Wurtzite crystal"

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Biermann, Amelie Laura [Verfasser], Axel [Akademischer Betreuer] Hoffmann, Christian [Akademischer Betreuer] Thomsen, Axel [Gutachter] Hoffmann, and Anna [Gutachter] Rodina. "Phonons and excitons in colloidal CdSe/CdS quantum dots with wurtzite and zincblende crystal structure / Amelie Laura Biermann ; Gutachter: Axel Hoffmann, Anna Rodina ; Axel Hoffmann, Christian Thomsen." Berlin : Technische Universität Berlin, 2018. http://d-nb.info/1168722160/34.

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Dicko, Hamadou. "Phonon-polaritons/phonons dans les cristaux mixtes à base de ZnSe de structures zincblende et wurtzite : diffusion Raman en avant/arrière, schéma de percolation." Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0169/document.

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La diffusion Raman est réalisée dans la géométrie inhabituelle de diffusion « en avant » (fonctionnant schématiquement en ‘mode de transmission’) pour explorer la nature et les propriétés des modes phonon-polaritons (polaires) de divers cristaux mixtes A1-xBxC à base de ZnSe. Un aperçu général est recherché en sélectionnant des systèmes qui se rapportent au même composé parent par souci de cohérence - à savoir ZnSe - mais avec différentes structures cristallines, i.e. de type zincblende (cubique : Zn1-xBexSe, ZnSe1-xSx, ZnxCd1-xSe) et de type wurtzite (hexagonal : Zn1-xMgxSe). Les systèmes retenus englobent toute la panoplie des comportements dans le régime de phonons natifs (non polaires) des phonons-polaritons, y compris les déviations sur-diversifiées [1 × (AB), 2 × (AC)] et sous-diversifiées de 1 × (AB, AC) par rapport au type -nominal [1 × (AB), 1 × (AC)], également dénommées multi-mode, 1-mode-mixte et 2-mode, respectivement, dans la classification admise des spectres Raman classiques de cristaux mixtes obtenus dans la géométrie conventionnelle de rétrodiffusion (fonctionnant schématiquement dans en 'mode réflexion'). La modélisation du contour des spectres Raman phonon-polariton obtenus est réalisée dans le cadre de la théorie de la réponse diélectrique linéaire en se basant sur des mesures d’ellipsométrie de l'indice de réfraction, avec des calculs ab initio en appui réalisés sur des motifs d'impureté prototypes dans les limites diluées (x~0,1), pour sécuriser le jeu réduit de paramètres d'entrée qui régissent le comportement phonon de base (non polaire) des cristaux mixtes étudiés. La discussion des spectres Raman obtenus en rétrodiffusion /avant est effectuée dans le cadre du modèle de percolation développé au sein de l’équipe pour une compréhension renouvelée des spectres optiques de vibration des cristaux mixtes. Ce modèle formalise une vision des choses selon laquelle les liaisons chimiques d'une espèce donnée vibrent à des fréquences différentes dans un cristal mixte selon que leur environnement est de même type ou de type différent à l'échelle très locale (des premiers, voire des seconds voisins). [...]
Inelastic Raman scattering is implemented in the unusual (near-)forward scattering geometry (schematically operating in the ‘transmission mode’) to explore the nature and properties of the (polar) phonon-polariton modes of various ZnSe-based A1-xBxC mixed crystals. An overall insight is searched by selecting systems that relate to the same parent compound for the sake of consistency – namely ZnSe – but with different crystal structures, i.e. of the zincblende (cubic: Zn1-xBexSe, ZnSe1-xSx, ZnxCd1-xSe) and wurtzite (hexagonal: Zn1-xMgxSe) types. Most of all, altogether the retained systems span the full variety of behavior in the native (non polar) phonon regime of the phonon-polaritons, including the over-diversified [1×(A−B),2×(A−C)] and sub-diversified 1×(A−B,A−C) deviations with respect to the nominal [1×(A−B),1×(A−C)] type, also referred to as the multi-mode, 1-mixed-mode and 2-mode types, respectively, in the admitted classification of the conventional Raman spectra of mixed crystals taken in the backscattering geometry (schematically operating in the ‘reflection mode’). Fair contour modeling of the obtained phonon-polariton Raman spectra is achieved within the linear dielectric response theory based on ellipsometry measurements of the refractive index and with ab initio calculations in support done on prototypal impurity motifs in both dilute limits (x~0,1), as needed to secure the reduced set of input parameters that govern the native (non polar) phonon mode behavior of the used mixed crystals. The backward/near-forward Raman spectra are discussed within the scope of the so-called percolation model developed within our group for a renewed understanding of the optical vibration spectra of the mixed crystals. This model formalizes a view that the chemical bonds of a given species vibrate at different frequencies in a mixed crystal depending on their like or foreign environment at the very local (first- or second-neighbor) scale. This introduces a generic 1-bond→2-mode phonon behavior for a mixed crystal, presumably a universal one. The main results enunciate as follows. [...]

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Calamba, Katherine. "Phase stability and defect structures in (Ti1-x,Alx)Ny hard coatings." Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0322.

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Cette étude met en évidence le rôle des lacunes d’azote et des défauts structuraux dans l’ingénierie de revêtements durs à stabilité de phase améliorée et dont les propriétés mécaniques sont compatibles avec des applications à haute température. Le nitrure de titane et d’aluminium (Ti,Al)N sous forme de revêtements est un matériau de choix pour la protection des outils de coupe pour métaux en raison de sa résistance supérieure à l’oxydation et à l’usure à haute température. La décomposition spinodale à haute température de la phase métastable cubique (Ti,Al)N en domaines cohérents de taille nanométrique de c-TiN et de c-AlN donne une dureté importante aux températures élevées. Un apport thermique encore plus élevé conduit à la transformation de c-AlN en w-AlN, ce qui nuit aux propriétés mécaniques du revêtement. Un moyen de retarder cette transformation est d'introduire des lacunes d'azote. Dans cette thèse, je montre que la combinaison d’une réduction de la teneur globale en azote du revêtement c-(Ti,Al)Ny(y <1) avec une faible tension de polarisation du substrat lors du dépôt par arc cathodique induit un retard encore plus prononcé de la transformation de la phase c-AlN en w-AlN. Dans de telles conditions, le durcissement par vieillissement est conservé jusqu'à 1100 ° C, ce qui correspond à la température la plus élevée signalée pour les films de (Ti,Al)N. Au cours des opérations de coupe, le mécanisme d'usure des films c-(Ti0.52Al0.48)Ny déposés par arc cathodique avec des teneurs en N de y = 0.92, 0.87 et 0.75 est influencé par l'interaction des lacunes d'azote, de la microstructure et des réactions chimiques avec le matériau de la pièce. Le revêtement y = 0.75 contient le plus grand nombre de macroparticules et présente, après usinage, une microstructure non homogène qui en abaisse la résistance à l'usure sur les flancs et les cratères. Le durcissement par vieillissement de l'échantillon y = 0.92 entraîne une résistance supérieure à l'usure sur le flanc, tandis que la structure dense de l'échantillon y = 0.87 empêche l'usure chimique qui se traduit par une excellente résistance à l'usure sur les cratères. Des films hétéroépitaxiés c-(Ti1-x, Alx)Ny (y = 0.92, 0.79 et 0.67) ont été déposés sur des substrats de MgO(001) et (111) en utilisant une technique de pulvérisation magnétron pour examiner en détail les défauts structuraux pendant la décomposition spinodale. À 900 °C, les films se décomposent pour former des domaines cohérents riches en c-AlN et c-TiN de forme allongée le long de la direction <001>. Les cartographies de déformation montrent que la plupart des contraintes se trouvent près de l'interface des domaines ségrégés et à l'intérieur des domaines c-TiN. Les dislocations s'agrègent favorablement dans c-TiN plutôt que dans c-AlN car ce dernier a une directionnalité plus forte des liaisons chimiques covalentes. À température élevée, la taille de domaine des films de c- (Ti, Al)Ny orientés (001) et (111) augmente avec la teneur en azote. Cela indique qu'il y a un retard dans le grossissement dû à la présence de plus de lacunes d’azote dans le film. [...]
This study highlights the role of nitrogen vacancies and defect structures in engineering hard coatings with enhanced phase stability and mechanical properties for high temperature applications. Titanium aluminum nitride (Ti,Al)N based materials in the form of thin coatings has remained as an outstanding choice for protection of metal cutting tools due to its superior oxidation resistance and high-temperature wear resistance. High-temperature spinodal decomposition of metastable (Ti,Al)N into coherent c-TiN and c-AlN nm-sized domains results in high hardness at elevated temperatures. Even higher thermal input leads to transformation of c-AlN to w-AlN, which is detrimental to the mechanical properties of the coating. One mean to delay this transformation is to introduce nitrogen vacancies. In this thesis, I show that by combining a reduction of the overall N-content of the c-(Ti,Al)Ny (y < 1) coating with a low substrate bias voltage during cathodic arc deposition an even more pronounced delay of the c-AlN to w-AlN phase transformation is achieved. Under such condition, age hardening is retained until 1100 °C, which is the highest temperature reported for (Ti,Al)N films. During cutting operations, the wear mechanism of the cathodic-arc-deposited c-(Ti0.52Al0.48)Ny with N-contents of y = 0.92, 0.87, and 0.75 films are influenced by the interplay of nitrogen vacancies, microstructure, and chemical reactions with the workpiece material. The y = 0.75 coating contains the highest number of macroparticles and has an inhomogeneous microstructure after machining, which lower its flank and crater wear resistance. Age hardening of the y = 0.92 sample causes its superior flank wear resistance while the dense structure of the y = 0.87 sample prevents chemical wear that results in excellent crater wear resistance. Heteroepitaxial c-(Ti1-x,Alx)Ny (y = 0.92, 0.79, and0.67) films were grown on MgO(001) and (111) substrates using magnetron putter deposition to examine the details of their defect structures during spinodal decomposition. At 900 °C, the films decompose to form coherent c-AlN- and c-TiN- rich domains with elongated shape along the elastically soft <001> direction. Deformation maps show that most strains occur near the interface of the segregated domains and inside the c-TiN domains. Dislocations favorably aggregate in c-TiN rather than c-AlN because the later has stronger directionality of covalent chemical bonds. At elevated temperature, the domain size of (001) and (111)- oriented c-(Ti,Al)Ny films increases with the nitrogen content. This indicates that there is a delay in coarsening due to the presence of more N vacancies in the film. The structural and functional properties (Ti1-x,Alx)Ny are also influenced by its Al content (x). TiN and (Ti1-x,Alx)Ny (y = 1, x = 0.63 and x = 0.77) thin films were grown on MgO(111) substrates using magnetron sputtering technique. Both TiN and Ti0.27Al0.63N films are single crystals with cubic structure. (Ti0.23,Al0.77)N film has epitaxial cubic structure only in the first few atomic layers then it transitions to an epitaxial wurtzite layer, with an orientation relationship of c-(Ti0.23,Al0.77)N(111)[1-10]ǀǀw-(Ti0.23,Al0.77)N(0001)[11-20]. The w-(Ti0.23,Al0.77)N shows phase separation of coherent nm-sized domains with varying chemical composition during growth. After annealing at high temperature, the domains in w-(Ti0.23,Al0.77)N have coarsened. The domains in w-(Ti0.23,Al0.77)N are smaller compared to the domains in c-(Ti0.27,Al0.63)N film that has undergone spinodal decomposition. The results that emerged from this thesis are of great importance in the cutting tool industry and also in the microelectronics industry, because the layers examined have properties that are well suited for diffusion barriers

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Walsh, Sean. "Rock Salt vs. Wurtzite Phases of Co1-xMnxO: Control of Crystal Lattice and Morphology at the Nanoscale." Thesis, 2012. http://hdl.handle.net/1911/71699.

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Diamond cuboid-, rhombohedron- and hexagon-shaped nanocrystals as well as branched rods of the solid solution Co1-xMnxO have been synthesized via a solvothermal synthetic route from manganese formate and cobalt acetate at elevated temperature. Rhombohedra and hexagons have dimensions no larger than 50 nm on the longest axis, rods have branches up to 150 nm long and cuboids grow up to 250 nm on a side. X-ray and electron diffraction and transmission electron microscopy analyses show that these nanoparticles are single crystals of wurtzite-type and rock salt-type Co1-xMnxO. Varying the surfactant, water and precursor ratios allows control of particle size, morphology and stoichiometry. Extending growth time at high temperatures (>370°C) leads to the disappearance of the wurtzite phase due to Ostwald ripening. Longer reaction times at temperatures between 345-365°C lead to more crystalline wurtzite-lattice particles. These results show that nanoparticle morphologies and crystal lattices arise from crystal growth and Ostwald ripening at different rates selecting for either small, smooth-surfaced wurtzite lattice particles or large, dendritically-grown rock salt lattice particles.

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Book chapters on the topic "Wurtzite crystal"

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Meyer, B. K. "InN, wurtzite modification: spin-orbit splittings, crystal field splitting." In New Data and Updates for I-VII, III-V, III-VI and IV-VI Compounds, 271. Berlin, Heidelberg: Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-48529-2_125.

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Vurgaftman, Igor, Matthew P. Lumb, and Jerry R. Meyer. "Absorption and Emission of Light in III–V Semiconductors." In Bands and Photons in III-V Semiconductor Quantum Structures, 93–138. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780198767275.003.0004.

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Previous chapters discussed the crystal structure and bandstructure of III–V semiconductors. This chapter shifts to the book’s second major topic: electronic interactions with light. It introduces the main ideas about how light waves propagate in semiconductor crystals and induce absorption, spontaneous emission, and stimulated emission in bulk semiconductors. It also considers the differences between the electronic interactions with light in zinc-blende and wurtzite crystals and what happens as the energy gap of the semiconductor is reduced to zero or when the crystal is two-dimensional.

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"Dislocations in Diamond, Zincblende, Wurtzite Structures and SiC." In Classical Theory of Crystal Dislocations, 215–52. WORLD SCIENTIFIC, 2017. http://dx.doi.org/10.1142/9789814749176_0011.

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Horodecki, A. J. "Semistatistically Defected Wurtzite Crystal Containing Pairs of Metal-Non-metal Vacancy." In December, 1471–75. De Gruyter, 1987. http://dx.doi.org/10.1515/9783112485446-005.

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Verma, R. "Comprehensive Study on Piezo-Phototronic Effect: Way Forward for Ferrite Based Solar Cells." In Materials Research Foundations, 279–310. Materials Research Forum LLC, 2021. http://dx.doi.org/10.21741/9781644901595-8.

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The wurtzite structured materials possess the inner-crystal piezopotential which comprehensively tune or control the charge carrier generation, separation, transportation, and recombination in optoelectronic devices. The piezo-phototronic effect provides a new working principle to the current traditional devices. Its effect on solar cells progresses made by the eminent scientists, and researchers in the field of piezo-phototronic modulated solar cells such as semiconductor-based, perovskite-based, multiple quantum-well (MQW) based and core/shell based. It has been described that the piezo-phototronic effect has improved the power conversion efficiency (PCE) of the solar cells, and the effect of temperature on the piezo-phototronic devices. Ferrite-based materials have emerged as a viable candidate for use in solar cells. As a result of this research, ferrite-based nanomaterials can now be used in solar cell applications, as well as the piezophototronic effect on these materials can be investigated. The piezo-phototronic effect is a novel subject that offers a new platform for material science and electronics to investigate.

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Vurgaftman, Igor, Matthew P. Lumb, and Jerry R. Meyer. "Detailed k·p Theory for Bulk III–V Semiconductors." In Bands and Photons in III-V Semiconductor Quantum Structures, 55–92. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780198767275.003.0003.

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The chapter discusses a full implementation of k·p theory for the eight bands near the energy gap in a III–V semiconductor. This model can precisely calculate the band structure for both conduction and valence bands near the energy gap. Even though only eight bands are explicitly included, the terms due to interactions with “remote” bands are present in the complete version of the theory. The chapter consider the physical meaning of the results and the effect that strain has on the semiconductor band structure. The Hamiltonians for both zinc-blende and wurtzite crystals are introduced.

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"Strain Energy of Thin Lattice-Mismatched Layers in Crystals with a Wurtzite Structure." In Statistical Thermodynamics of Semiconductor Alloys, 201–4. Elsevier, 2016. http://dx.doi.org/10.1016/b978-0-12-803987-8.15002-6.

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Hobodecki, A. J. "On the Possibility of Polytypism in Semistatistically Defected Wurtzite-type Crystals of CdS." In December, 1586–88. De Gruyter, 1987. http://dx.doi.org/10.1515/9783112485446-038.

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Schreiber, J., S. Vasnyov, and L. Hoering. "SEM CL studies on dynamics and recombination activity of glide dislocations in zincblende and wurtzite semiconductor crystals." In Microscopy of Semiconducting Materials 2003, 549–54. CRC Press, 2018. http://dx.doi.org/10.1201/9781351074636-124.

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Conference papers on the topic "Wurtzite crystal"

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Sibirev, N. V., Y. S. Berdnikov, V. N. Sibirev, and V. G. Dubrovskii. "Stabilization of wurtzite crystal phase in arsenide nanowires via elastic stress." In 2020 International Conference Laser Optics (ICLO). IEEE, 2020. http://dx.doi.org/10.1109/iclo48556.2020.9285853.

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Ma, Jinlong, Baoling Huang, Wu Li, and Xiaobing Luo. "Intrinsic Thermal Conductivity of Wurtzite AlxGa1-xN, InxGa1-xN and InxAl1-xN From First-Principles Calculation." In ASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems collocated with the ASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/ipack2015-48032.

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The thermal conductivities of the alloys of wurtzite AlN, GaN and InN are usually analyzed with the virtual crystal model based on the values of the constituent compounds. However, latest experiments and calculations reveal that the thermal conductivity of wurtzite InN is about three times larger than the previously used value. Thus it is necessary to reanalyze the thermal conductivities of these alloys. In this work, the intrinsic thermal conductivities of AlxGa1−xN, InxGa1−xN and InxAl1−xN are calculated with first-principles calculations along with the virtual crystal treatment. It is found that the thermal conductivities of these alloys are strongly suppressed even after a small amount of alloying. For instance, the in-plane and out-of-plane thermal conductivities of In0.99Ga0.01 N are 66 Wm−1K−1 and 76 Wm−1K−1 respectively, while they are 40 Wm−1K−1 and 48 Wm−1 K−1 for In0.99Al0.01 N, compared with the corresponding values of 130 Wm−1 K−1 and 145 Wm−1 K−1 for bulk wurtzite InN. When the fraction x varies from 0.2 to 0.8, the thermal conductivities of the alloys do not change much. Additionally, the distribution of mean free path indicates that the size effect can persist up to 10μm for both pure compounds and their alloys at room temperature.

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Kuo, C. C., W. R. Liu, W. F. Hsieh, C. H. Hsu, H. C. Hsu, and L. C. Chend. "Crystal symmetry breaking of wurtzite to orthorhombic in nonpolar a-ZnO epi-films." In LEOS 2009 -22nd Annuall Meeting of the IEEE Lasers and Electro-Optics Society (LEO). IEEE, 2009. http://dx.doi.org/10.1109/leos.2009.5343083.

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Desai, A. V., and M. A. Haque. "Effect of Electromechanical Coupling on the Young’s Modulus of Zinc Oxide Nanowires." In ASME 2008 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/detc2008-49911.

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The Young’s modulus of zinc oxide nanowires was measured to be significantly lower than bulk zinc oxide, which cannot be explained within the framework of existing theories. We propose that the strong electromechanical coupling in piezoelectric materials, such as zinc oxide, influences the measured mechanical properties. The asymmetric wurtzite crystal structure and the ionic nature of the molecular bonding result in internal electric fields during straining of the zinc oxide nanowire, which in turn lead to reduction in the measured modulus. In case of flexural deformation, additional electromechanical coupling is present due to the flexoelectric effect.

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Rosenthal, S. J., A. T. Yeh, A. P. Alivisatos, and C. V. Shank. "Size Dependent Absorption Anisotropy Measurements of CdSe Nanocrystals: Symmetry Assignments for the Lowest Exciton State." In International Conference on Ultrafast Phenomena. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/up.1996.tue.45.

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Semiconducting nanocrystals smaller in size than the bulk Bohr exciton display quantum confinement, leading to a size dependent energy gap and concentration of oscillator strength into a few transitions. Given these properties these materials are being investigated for potential device applications. CdSe nanocrystals have already been implemented in tunable light emitting diodes.1 We have performed absorption anisotropy experiments on CdSe crystals ranging in diameter from 30-50A with the goal of elucidating the symmetry of the lowest energy optical transition and the earliest events of carrier evolution. The optical anisotropy is defined as R(t)=I‖ (t)-I⊥ (t)/K(t), where K(t) is the total population decay (I‖ + 2I⊥). The initial value of the anisotropy, R(0), is indicative of the nature of the optical transition. For example, if the transition is spherically degenerate, as for C60, R(0) is expected to be 0.0. A linear dipole transition has R(0)=0.4 and for a degenerate planar transition R(0)=0.15.2 The decay in the anisotropy may contain contributions from rotational diffusion, rotation of the transition dipole, as in an isomerization reaction, or population transfer between two excited state levels with transition dipoles of different directions. High time resolution measurements performed on nanocrystals thus give us insight into the shape of the optical transition and the earliest dynamics of the excited carriers. We’ve discovered that a competition exists between the intrinsic wurtzite crystal field and the nonspherical confinement in the crystal3 which dictates the symmetry of the first exciton state. The crystals are thus intrinsically dichroic, a phenomenon which may be exploited in device applications.

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Wilson, William L., M. Bawendi, L. Rothberg, T. Jedju, L. Brus, and M. L. Steigerwald. "Absorption Saturation Dynamics in Capped CdSe Microcrystallites Exhibiting Quantum Confinement." In International Conference on Ultrafast Phenomena. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/up.1990.thc10.

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Restriction of carrier wave functions in semiconductor structures of reduced dimensionality results in increased oscillator strength in the excitonic absorption which can be exploited in the design of novel nonlinear optical devices[1]. We report transient bleaching studies of CdSe "quantum dots" whose size is small relative to the bulk material exciton radius. Subpicosecond hole burning and steady-state luminescence spectroscopies are used to characterize the spectral dynamics and isolate the single particle spectrum of these 45 Å diameter CdSe microcrystallites. These clusters, which are grown by a new synthetic method,[2], have well developed wurtzite crystal structure,[3], high quantum yield of band edge luminescence, low saturation intensities, (≈100µJ/cm2) and long bleaching recovery times. Our measurements were performed at 25K in dilute glasses.

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Fukui, T., Y. Hiraya, F. Ishizaka, and K. Tomioka. "Phase Transition from Zinc Blende to Wurtzite and Green Emission of AlInP Grown on (10-10) GaN by Crystal Structure Transfer Epitaxy." In 2016 International Conference on Solid State Devices and Materials. The Japan Society of Applied Physics, 2016. http://dx.doi.org/10.7567/ssdm.2016.d-4-03.

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Kushnir, Oleg S., V. A. Grabovski, O. S. Dzendzelyuk, and L. P. Lutsiv-Shumski. "Light propagation in wurtzite-type crystals with the Jones calculus." In International Workshop on Optoelectronic and Hybrid Optical/Digital Systems for Image/Signal Processing, edited by Simon B. Gurevich, Zinovii T. Nazarchuk, and Leonid I. Muravsky. SPIE, 2000. http://dx.doi.org/10.1117/12.388433.

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Hartung, S., S. Kück, T. Danger, K. Petermann, and G. Huber. "ESA Measurements of Cr4+-doped Crystals with Wurtzite-like Structure." In Advanced Solid State Lasers. Washington, D.C.: OSA, 1996. http://dx.doi.org/10.1364/assl.1996.tl8.

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Luan, Xing-He, Chuang Feng, Hong-Bo Qin, Fan-Fan Niu, and Dao-Guo Yang. "The electronic properties of zinc-blende GaN, wurtzite GaN and pnma-GaN crystals under pressure." In 2017 18th International Conference on Electronic Packaging Technology (ICEPT). IEEE, 2017. http://dx.doi.org/10.1109/icept.2017.8046716.

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