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Showing 1 to 20 of 35 for “"bandstructure"”.
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Bandstructure and related aspects of some crystalline free-electron-like metals
Contains fulltext : mmubn000001_026587378.pdf (Publisher’s version ) (Open Access)
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ATOMISTIC MODELING OF PHONON BANDSTRUCTURE AND TRANSPORT FOR OPTIMAL THERMAL MANAGEMENT IN NANOSCALE DEVICES
… that the use of empirically fitted phonon bandstructure parameters overestimates the temperature difference between the hot and the cold sides and the overall cooling efficiency of the system, thereby, demanding the use of the BTE derived thermal conductivity in the calculation of thermal …
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Bandstructure calculations for holes in GaAs and simulations of dc conductance in electron quantum point contacts
We present simulations of the bandstructure of holes in GaAs for an infinite square well potential using the Luttinger Hamiltonian and subband k•p theory. Our calculations explicitly include Rashba and Dresselhaus spin-orbit terms. The effective mass of the holes at the zone center is calculated. …
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Characterization of mid-infrared quantum cascade lasers
… a large portion of the quantum mechanical bandstructure could be determined, along with many of the parameters characterizing crystal growth quality. In addition, high-resolution transmission spectroscopy was used to find the properties of the QCL waveguide. In order to find the …
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An Experimental Study of Impact Ionization in Compound Semiconductors
… ionization coefficients have indicated that the bandstructure can have a strong influence on the impact ionization process. In this thesis, the effects of crystallographic orientation, composition and temperature on impact ionization are reported for measurements done on InP, Al$\sb{\rm …
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Numerical studies of femtosecond laser spectroscopy experiments in gallium arsenide material and quantum well structures
… by an ensemble Monte Carlo method including hole bandstructure effects. The time-dependent distributions from the Monte Carlo simulations in turn serve as a basis for interpreting transient differential transmission data, leading to an understanding of relaxation processes and the determination of …
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Optical and electrical properties of narrow gap germanium-tin alloys with high tin contents for middle and far infrared applications
… contain rich information about the electronic bandstructure. Analyzing the second derivative of the dielectric function enables the determination of the energy levels of the critical point transitions in the electronic bandstructure. Second derivative analysis results of the high Sn content …
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Electrostatic Analysis of Nanoelectromechanical Systems
… and graphene can significantly change the bandstructure of graphene. This is caused by the covalent bonding formed by C and surface Si atoms, which changes the pi-band network of the graphene layer. The dispersion curves and density of states calculations show that the bonded Si-C surface …
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Optomechanics of two- and three-dimensional soft photonic crystals
… based approach is taken to compute the photonic bandstructure to estimate light propagation through the structure for other angles of light incidence. To obtain a detailed picture of the change in optical properties due to a pattern transformation, we study simple 2-D elastomer photonic crystals …
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Ab initio Beschreibung der elektronischen Struktur und der Transporteigenschaften von metallischen Nanodrähten
… of the wire is assumed. The dependence of the bandstructure and the density of states from thickness and shape of the cross-section is discussed. The quantum confinement of the eigenstates is analysed. By comparing the results of the Na and Cu wires, the influence of the d-electrons is shown. …
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Wachstum und Charakterisierung von Halbleiternanostrukturen auf vorstrukturiertem Substrat
… growth mechanisms on such special surfaces, bandstructure calculations are used to help understanding the quantization properties of the resulting complex structures of interconnected three-, two- and one-dimensional areas. Cathodo- and photoluminescence experiments prove the formation of …
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Two classes of unconventional photonic crystals
… of the lattice, that accurately describes its bandstructure.
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Gallium Arsenide based photonic crystal surface emitting lasers
… through optical waveguide and photonic bandstructure modelling. It is shown that increased 1D and 2D coupling strength, a measure of the strength of feedback in a device, is achieved in a PCSEL which utilises a void/semiconductor photonic crystal contrast as opposed to all-semiconductor …
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n-type silicon-germanium based terahertz quantum cascade lasers
… mass/envelope function model of the electronic bandstructure is developed, taking into account the effects of strain and crystal orientation. Scattering models for Coulombic interactions, structural imperfections and interactions with phonons (lattice vibrations) are developed and used to …
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Quantum transport in Josephson junctions
… can produce intricate fractals in an electron’s bandstructure. We then introduce a numerical algorithm which, although creates numerical instabilities, improves the speed of conventional Green’s function calculations. Finally, we study the electrical current, and the bound states which carry this …
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Unipolar barrier strained layer superlattice infrared photodiodes : physics and barrier engineering
… detectors. This work has been focused on the bandstructure simulation, molecular beam epitaxy (MBE) growth optimization, physical understating, and heterojunction barrier engineering of T2SL, in midwave infrared (MWIR, 3-5\uf06dm) and longwave infrared (LWIR, 8-12\uf06dm) regimes. The …
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Monte Carlo Simulation of Silicon Devices Including Quantum Correction and Strain
… Different materials can be added by changing the bandstructure and scattering rate tables, with only cosmetic changes required in the internal code. As a test case, strained silicon is implemented and bulk strained silicon simulations are performed to verify agreement with experimental data. …
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CRYSTAL STRUCTURE ENGINEERING FOR IMPROVED PERFORMANCE OF EMERGING NANOSCALE DEVICES
… (2) Augment/extend the open source NEMO 3-D bandstructure simulator by incorporating a recently proposed first principles based model to gauge the importance of nonlinear piezoelectricity on the single-particle electronic states and interband optical transitions in emerging In(Ga)N/GaN …
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Fully coupled electrical and optical simulation of vertical cavity surface emitting lasers
… It is shown that inclusion of an accurate bandstructure is important for obtaining correct laser output characteristics such as the modulation response. Finally, a fast new Green's function based optical solver (VMS) has been included self-consistently within MINILASE. The speed of VMS …
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Photoacoustic measurement of bandgaps of thermoelectric materials
… challenges remain. The bandgap is a key piece of bandstructure information, but is difficult to determine for heavily doped thermoelectric materials. Under heavy doping conditions, the effective mass and bandgap both change due to the formation of Urbach band tails and other defect states within …
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