Manifestation of defects in phonon spectra of binary zinc-blende compounds

The first- and second-order Raman spectra of ZnSe have been measured and an interpretation of the spectra has been carried out. The first-order spectrum yielded the values [Formula: see text] and [Formula: see text] for the longitudinal and transverse optical phonons at the center of the Brillouin zone. The zone boundary frequencies at the critical points X, L, and W have been estimated from the second-order spectrum. These frequencies were chosen to be consistent with both the experimental results and a theoretical model. The resulting values were further checked for consistency with a sum rule and by using regularities observed previously in the phonon spectra of zinc blende semiconductors.

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Thermodynamic Properties of Wurtzite and Zinc-Blende AlN

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.455.127 ◽

2013 ◽

Vol 455 ◽

pp. 127-130

Author(s):

Xue Mei Cai ◽

Jing Mei Wang ◽

Qian Neng Zhou

Keyword(s):

Free Energy ◽

Thermodynamic Properties ◽

Room Temperature ◽

Potential Method ◽

Zinc Blende ◽

Phonon Spectra ◽

The Difference ◽

Increasing Temperature ◽

Pseudo Potential ◽

Good Agreement

In this paper, we carry out linear response calculation to determine the phonon density of states and the thermodynamic properties of the wurtzite and zinc-blende AlN by using the norm-conserving pseudo-potential method. The optimized lattice constant is in good agreement with the available experimental data. The internal energies increase almost linearly with temperature and the phonon free energy curves move down with increasing temperature in both structures. The zero value of the lattice vibration free energy appears at temperature 707K in wurtzite and 728K in zinc-blende AlN respectively. The specific heat capacity of the wurtzite AlN is higher than that of the zinc-blende AlN at room temperature owing to the difference of the phonon spectra.

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Zinc-blende Mn1−xMnxTe - A new diluted magnetic semiconductor system

Journal of Crystal Growth ◽

10.1016/s0022-0248(97)00800-2 ◽

1998 ◽

Vol 184-185 (1-2) ◽

pp. 976-979

Author(s):

E Janik

Keyword(s):

Diluted Magnetic Semiconductor ◽

Magnetic Semiconductor ◽

Zinc Blende ◽

Semiconductor System ◽

Diluted Magnetic

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FIRST PRINCIPLES CALCULATION OF THE PHONON SPECTRA OF SOLIDS

Le Journal de Physique Colloques ◽

10.1051/jphyscol:19816181 ◽

1981 ◽

Vol 42 (C6) ◽

pp. C6-625-C6-627 ◽

Cited By ~ 2

Author(s):

P. E. Van Camp ◽

V. E. Van Doren ◽

J. T. Devreese

Keyword(s):

First Principles ◽

First Principles Calculation ◽

Phonon Spectra

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EXCITON INSULATOR STATES IN MATERIALS WITH â€˜MEXICAN HATâ€™ BAND STRUCTURE DISPERSION AND IN GRAPHENE

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v11i1.6947 ◽

2015 ◽

Vol 11 (1) ◽

pp. 2927-2949

Author(s):

Lyubov E. Lokot

Keyword(s):

Band Structure ◽

Three Dimensional ◽

Dimensional Sphere ◽

Electron Hole ◽

Dinger Equation ◽

Fermi Sphere ◽

Zinc Blende ◽

Bulk Gan ◽

Structure Dispersion ◽

Excitonic States

In the paper a theoretical study the both the quantized energies of excitonic states and their wave functions in grapheneand in materials with "Mexican hat" band structure dispersion as well as in zinc-blende GaN is presented. An integral twodimensionalSchrÃ¶dinger equation of the electron-hole pairing for a particles with electron-hole symmetry of reflection isexactly solved. The solutions of SchrÃ¶dinger equation in momentum space in studied materials by projection the twodimensionalspace of momentum on the three-dimensional sphere are found exactly. We analytically solve an integral twodimensionalSchrÃ¶dinger equation of the electron-hole pairing for particles with electron-hole symmetry of reflection. Instudied materials the electron-hole pairing leads to the exciton insulator states. Quantized spectral series and lightabsorption rates of the excitonic states which distribute in valence cone are found exactly. If the electron and hole areseparated, their energy is higher than if they are paired. The particle-hole symmetry of Dirac equation of layered materialsallows perfect pairing between electron Fermi sphere and hole Fermi sphere in the valence cone and conduction cone andhence driving the Cooper instability. The solutions of Coulomb problem of electron-hole pair does not depend from a widthof band gap of graphene. It means the absolute compliance with the cyclic geometry of diagrams at justification of theequation of motion for a microscopic dipole of graphene where >1 s r . The absorption spectrums for the zinc-blendeGaN/(Al,Ga)N quantum well as well as for the zinc-blende bulk GaN are presented. Comparison with availableexperimental data shows good agreement.

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