We investigate how the template crystal orientation indices (hk.??) can influence intensity of density elastic energy and polarization fields in wurtzite nitrides oxides semiconductor strained layer heterostructures. propose analytical relations between angle ?, defined as direction sixfold axis unstrained material normal to growth plane, (i) value total (ii) stored layer. find that quasi-cancellation quantum confined stark effect (QCSE) be generally obtained by carefully selecting set. This...

Hall-effect and transverse-magnetoresistance measurements were performed on pure n-type InAs samples (n\ensuremath{\simeq}2\ifmmode\times\else\texttimes\fi{}${10}^{16}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$) under magnetic fields up to 180 kG hydrostatic pressures 18 kbar in the temperature range 2.7--8 K. At P13 kbar, freezeout takes place into a shallow-donor level which shifts downward from \ensuremath{\Gamma} conduction-band minimum with pressure coefficient -0.077 meV/kbar. P>13...

Hall-coefficient and transverse magnetoresistivity measurements performed in magnetic fields up to 18 T hydrostatic pressures 16.5 kbar reveal several features of the behavior shallow donorlike impurity states n-type InP with concentrations spanning metal-insulator transition (2.2\ifmmode\times\else\texttimes\fi{}${10}^{15}$...

Abstract We present a theoretical study of the effects lattice‐mismatch induced built‐in strain on electronic properties valence band states in wurtzite ZnO/Zn 1–x Mg x O Quantum Well (QW) heterostructures. In this purpose, 6x6 k · p method has been used to incorporate and nonparabolicity. The energies corresponding transitions between conduction (C), heavy hole (HH), light (LH) crystal‐field split‐off (CH) bands have calculated as function composition strain. also energy dispersions wave...

We present a theoretical study of the optical absorption coefficient Urbach tail broadening parameter Γ behavior in Hg1−xCdxTe alloy semiconductor 0.21 ≤ x 0.6 composition interval. This interval corresponds to very attractive 0.10 EG 0.75 eV medium infrared (MIR) and far (FIR) ranges. compare two nonparabolic models based on Kane 4-band formalism, one including Burstein–Moss shift called NPBM-model other without NP-model. By comparing results both with existing experimental data, we show...

Abstract This work examines the grown of Zn 1-x Co x O films at different concentrations 420°C by ultrasonic spray deposition. The effect concentration on optical characterization, structure crystallinity and electrical conductivity was studied. Transmission spectra presented three edges in visible region, it observed range 541 656 nm wavelengths, which related to d-d transitions 2+ ion with 3d 7 high-spin configurations a tetrahedral crystal field formed neighboring 2− ions. gap energy...

Abstract We perform a theoretical study of In x Al 1‐x N/ZnO and Ga strained Quantum Well (QW) Lasers oriented along the non‐polar A‐plane axis. order to determine energy band‐offsets in both heterostructures as function alloy composition, we use ab‐initio method compute total energies these systems. Then, k · P within envelop formalism conduction valence subband structures for various compositions well widths. Finally, calculate Laser gain such QW heterostructures. Our results show that...

The properties of sulfur- and selenium-related impurity states have been studied as a function pressure composition in heavily doped ${\mathrm{Ga}}_{\mathrm{x}}$${\mathrm{In}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$Sb. Hall-coefficient electrical-resistivity measurements were made under hydrostatic pressures up to 25 kbar, the alloy range 0.30\ensuremath{\lesssim}x\ensuremath{\lesssim}0.78 temperature 77 K\ensuremath{\lesssim}T\ensuremath{\lesssim}300 K. In both S-doped Se-doped samples,...

Electronic structures, effect of the substitution and structure physical-chemistry properties relationship for macrolide derivatives, have been studied by PM3 ab initio methods. In present work, calculated values, namely net charges, bond lengths, MESP, dipole moments, electron-affinities, heats formation, then, we treated structural, physical chemical relationships a series derivatives with inhibition activity against Mycobacterium tuberculosis. QSAR studies were done these using...

We present a theoretical study based on the perturbative Luttinger-Kohn model so-called k.P model[1] of high internal electric fields and built-in strain effects laser properties wide bandgap II-VI ZnO/MgxZn1-xO Zn1-yCdyO/ZnO Quantum Well (QW) lasers operating in near UV wavelength range. The field (>1MV/cm) are due to non-centrosymmetric Würtzite crystal structure with spontaneous piezoelectric polarizations. Internal found induce red-shift wavelength, reduce drastically gain through...

Magnetic freeze-out experiments under hydrostatic pressure have been performed in the temperature range 4.2-77 K on direct-band-gap Si-doped AlGaAs samples. Successive illuminations used to monitor concentrations of metastable shallow states arising from DX centres. With increasing those states, evidence is given for an insulator-metal transition confirming Gamma character these impurity states. Moreover a shallow-deep shown hold at X=0.32 as result appearance gap x=0.30 localized level also...

teaching and research institutions in France or abroad, from public private centers.L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques niveau recherche, publiés ou non, émanant des établissements d'enseignement recherche français étrangers, laboratoires publics privés.

We present a k.P‐theory optimization study of type I Ga1‐xInxNySb1‐y/AlxGa1‐xNySb1‐y dilute antimonide nitrides strained quantum well lasers (QWL) for 3–4 μm mid infrared (MIR) wavelengths where N contents are kept ≤2%. show the critical influence on laser parameters such small nitrogen amounts in this very narrow ≤2% range. The best structure is found to be Ga0.9In0.1N0.02Sb0.98/Al0.1Ga0.9N0.01Sb0.99 which shows significantly increased emission up λ≈4 μm, improved modal gain G order 250...