We present a comprehensive, up-to-date compilation of band parameters for the technologically important III–V zinc blende and wurtzite compound semiconductors: GaAs, GaSb, GaP, GaN, AlAs, AlSb, AlP, AlN, InAs, InSb, InP, and InN, along with their ternary and quaternary alloys. Based on a review of the existing literature, complete and consistent parameter sets are given for all materials. Emphasizing the quantities required for band structure calculations, we tabulate the direct and indirect energy gaps, spin-orbit, and crystal-field splittings, alloy bowing parameters, effective masses for electrons, heavy, light, and split-off holes, Luttinger parameters, interband momentum matrix elements, and deformation potentials, including temperature and alloy-composition dependences where available. Heterostructure band offsets are also given, on an absolute scale that allows any material to be aligned relative to any other.

Band parameters for III–V compound semiconductors and their alloys

We present models for the optical functions of 11 metals used as mirrors and contacts in optoelectronic and optical devices: noble metals (Ag, Au, Cu), aluminum, beryllium, and transition metals (Cr, Ni, Pd, Pt, Ti, W). We used two simple phenomenological models, the Lorentz-Drude (LD) and the Brendel-Bormann (BB), to interpret both the free-electron and the interband parts of the dielectric response of metals in a wide spectral range from 0.1 to 6 eV. Our results show that the BB model was needed to describe appropriately the interband absorption in noble metals, while for Al, Be, and the transition metals both models exhibit good agreement with the experimental data. A comparison with measurements on surface normal structures confirmed that the reflectance and the phase change on reflection from semiconductor-metal interfaces (including the case of metallic multilayers) can be accurately described by use of the proposed models for the optical functions of metallic films and the matrix method for multilayer calculations.

Optical properties of metallic films for vertical-cavity optoelectronic devices.

In this paper, we describe the spectral characteristics that can be achieved in fiber reflection (Bragg) and transmission gratings. Both principles for understanding and tools for designing fiber gratings are emphasized. Examples are given to illustrate the wide variety of optical properties that are possible in fiber gratings. The types of gratings considered include uniform, apodized, chirped, discrete phase-shifted, and superstructure gratings; short-period and long-period gratings; symmetric and tilted gratings; and cladding-mode and radiation-mode coupling gratings.

Fiber grating spectra

The historical beginnings of photosensitivity and fiber Bragg grating (FBG) technology are recounted. The basic techniques for fiber grating fabrication, their characteristics, and the fundamental properties of fiber gratings are described. The many applications of fiber grating technology are tabulated, and some selected applications are briefly described.

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Fiber Bragg grating technology fundamentals and overview

Plasmons describe collective oscillations of electrons. They have a fundamental role in the dynamic responses of electron systems and form the basis of research into optical metamaterials 1–3 . Plasmons of two-dimensional massless electrons, as present in graphene, show unusual behaviour 4–7 that enables new tunable plasmonic metamaterials 8–10 and, potentially, optoelectronic applications in the terahertz frequency range 8,9,11,12 .H ere we explore plasmon excitations in engineered graphene microribbon arrays. We demonstrate that graphene plasmon resonances can be tuned over a broad terahertz frequency range by changing micro-ribbon width and in situ electrostatic doping. The ribbon width and carrier doping dependences of graphene plasmon frequency demonstrate power-law behaviour characteristic of two-dimensional massless Dirac electrons 4–6 . The plasmon resonances have remarkably large oscillator strengths, resulting

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Graphene plasmonics for tunable terahertz metamaterials

Photocapacitance measurements have been used to determine the electron photoionization cross section of the centers responsible for persistent photoconductivity in Te-doped ${\mathrm{Al}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{As}$. The cross-section data, which have been obtained at various temperatures and for crystals of various alloy compositions, are fitted by a theoretical line shape that is valid for large lattice relaxation. The line shape and thermal broadening can best be fit by a binding energy of 0.10\ifmmode\pm\else\textpm\fi{}0.05 eV and a Franck-Condon energy of 0.75\ifmmode\pm\else\textpm\fi{}0.1 eV. These values are in good qualitative agreement with the large-lattice-relaxation model of persistent photoconductivity which we recently proposed. We show that the 0.10-eV binding energy is also consistent with experiments that locate this energy relative to the Fermi level. The dependence of the properties of the persistent-photoconductivity center on the donor doping of the samples leaves little doubt that this center involves a donor atom, but because the center is not effective-mass-like, we believe that it is a complex also involving another constituent. Accordingly, we designate it as a "$\mathrm{DX}$" center. The anomalously-large Franck-Condon energy (Stokes shift) and apparent fact that the unoccupied state of the $\mathrm{DX}$ center is resonant with the conduction band, yet sufficiently localized to produce a large relaxation, are thus well established. These considerations lead us to the propose that the most likely model for $\mathrm{DX}$ centers in ${\mathrm{Al}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{As}$, and perhaps in other compound semiconductors as well, is a complex involving a donor and an anion vacancy. We show that such a model is qualitatively consistent with the overall trends in persistent-photoconductivity behavior observed in a variety of III-V and II-VI semiconductors.

Trapping characteristics and a donor-complex ( DX ) model for the persistent-photoconductivity trapping center in Te-doped Al x Ga 1 − x As

A new model, based on an extremely strong coupling between the electronic and vibrational systems of certain defect centers, is proposed to explain the phenomenon of persistent photoconductivity observed in some compound semiconductors. The model is supported by data on donor-related defects in $n$-type ${\mathrm{Al}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{As}$ which exhibit the features characteristic of this effect: a very large Stokes shift (thermal depth, \ensuremath{\sim}0.1 eV; optical depth, \ensuremath{\sim}1.2 eV); and a very small (${10}^{\ensuremath{-}30}$ ${\mathrm{cm}}^{2}$), thermally activated, electron-capture cross section at temperatures below 77 K.

Large-Lattice-Relaxation Model for Persistent Photoconductivity in Compound Semiconductors

The two-dimensional plasmon of an $n$ inversion layer of (100) $p$-type Si is observed at a fixed wave vector as a function of electron density. The position, width, and strength of the resonance agree with existing theory at electron densities \ensuremath{\gtrsim}${10}^{12}$/${\mathrm{cm}}^{2}$. At lower densities, the resonance position is below the predicted value, implying a substantial increase in the electron mass.

Observation of the Two-Dimensional Plasmon in Silicon Inversion Layers

The ionization rates of charge carriers in silicon have been measured and fit to the recent theoretical calculations of Baraff; in contrast, none of the existing published data could be fit to these theoretical curves The study has been made using microplasma-free junctions of demonstrably high, uniform local multiplication A new and considerably simplified approach to the problem of extracting the ionization rates from the multiplication data has been used By employing much more precise control of the electron and hole currents used to initiate the multiplication process, the hole ionization rate at electric fields less than 300 kV/cm is found to be more than an order of magnitude smaller than any previously published measurements Hole and electron ionization rates have been measured in the same junction and consequently in the identical scattering environment The threshold energy is determined to be ${E}_{g}\ensuremath{\le}{E}_{i}\ensuremath{\le}15{E}_{g}$, and the mean free path for scattering of high-energy electrons is $50 \AA{}\ensuremath{\le}{\ensuremath{\lambda}}_{e}\ensuremath{\le}70 \AA{}$ and for energetic holes $30 \AA{}\ensuremath{\le}{\ensuremath{\lambda}}_{h}\ensuremath{\le}45 \AA{}$ Measurement of ionization rates at various temperatures substantiates the assumption that the energy-loss mechanism is the emission of optical phonons In addition, significant differences of the electrical breakdown characteristics of microplasma-free junctions are discussed as well as their preparation

Ionization Rates of Holes and Electrons in Silicon

We carry out a detailed study of catastrophic degradation (CD) in DH laser material from which we reach two conclusions. First, local melting occurs and is due to intense nonradiative recombination of minority carriers at a cleaved surface or at a defect. The minority carriers are generated by absorbed superradiant light. Second, the dark line associated with CD results from propagation of a molten zone confined to the active layer. It is recrystallized epitaxially after the laser pulse but remains highly nonradiative because large numbers of point defects and dislocation loops are quenched into this region during rapid cooling from the molten state. Catastrophic damage was induced by exciting superradiance in the DH material with a cavity‐dumped Ar‐ion laser. The melting and recrystallization were established by observing a redistribution of Ga and Al in the x=0.08 active layers by TEM studies. The point defects were detected by scanning junction photocurrent measurements, electron‐beam‐induced current, ...

Ralph A. Logan

Papers

Trapping characteristics and a donor-complex ( DX ) model for the persistent-photoconductivity trapping center in Te-doped Al x Ga 1 − x As

Large-Lattice-Relaxation Model for Persistent Photoconductivity in Compound Semiconductors

Observation of the Two-Dimensional Plasmon in Silicon Inversion Layers

Ionization Rates of Holes and Electrons in Silicon

Catastrophic damage of AlxGa1−xAs double‐heterostructure laser material