Lattice Properties of Ge and GaAs Strained-Layers on Si

1994 ◽  
Vol 356 ◽  
Author(s):  
Resul Eryigit ◽  
Zhifeng Sui ◽  
Irving P. Herman
Keyword(s):  
Experimental Data ◽  
Thin Films ◽  
Lattice Dynamics ◽  
Phonon Dispersion ◽  
Group Iv ◽  
Dynamics Model ◽  
Strained Layers ◽  
Quasiharmonic Approximation ◽  
Semiconductor Thin Films ◽  
Phonon Dispersion Relations

AbstractA phenomenological lattice dynamics model has been developed that describes how strain affects phonon frequencies and elastic constants in Group IV and III-V semiconductor thin films and strained layers. Using this model, the phonon dispersion relations for strained-layer heterostructures of Ge and GaAs on Si have been obtained in the quasiharmonic approximation. This model uses available experimental data and can predict the effect of arbitrary strains on thin films.

Unpaired forces in the study of lattice dynamics of thorium

1979 ◽  
Vol 57 (11) ◽  
pp. 1838-1842 ◽  
Author(s):  
K. N. Awasthi ◽  
S. S. Kushwaha
Keyword(s):  
Experimental Data ◽  
Phenomenological Model ◽  
Lattice Dynamics ◽  
Phonon Dispersion ◽  
Body Rotation ◽  
Symmetry Requirement ◽  
Screened Coulomb Potential ◽  
Three Body ◽  
Good Agreement ◽  
Phonon Dispersion Relations

A phenomenological model that considers interaction between ions in terms of two-body (central) and three-body (unpaired) forces and evaluates the effect of electron–ion interaction through a screened coulomb potential is developed for studying the lattice dynamics of thorium. The model satisfies the symmetry requirement of a lattice and fulfils the condition of invariance under rigid body rotation. Computed phonon dispersion relations and (θD – T) curve for thorium are in reasonably good agreement with the corresponding experimental data.

Lattice dynamics of xenotime: The phonon dispersion relations and density of states ofLuPO4

1997 ◽  
Vol 56 (18) ◽  
pp. 11584-11592 ◽  
Author(s):  
J. C. Nipko ◽  
C.-K. Loong ◽  
M. Loewenhaupt ◽  
M. Braden ◽  
W. Reichardt ◽  
...  
Keyword(s):  
Density Of States ◽  
Lattice Dynamics ◽  
Phonon Dispersion ◽  
Dispersion Relations ◽  
Phonon Dispersion Relations

Effects of Confinement and Surface Reconstruction on the Lattice Dynamics and Thermal Transport Properties of Thin Films

2007 ◽  
Author(s):  
Joseph E. Turney ◽  
A. J. H. McGaughey ◽  
C. H. Amon
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Lattice Dynamics ◽  
Phonon Dispersion ◽  
Phonon Transport ◽  
Phonon Dispersion Curves ◽  
Lennard Jones ◽  
Silicon Thin Films ◽  
Plane Direction ◽  
Bulk System

Phonon transport in argon and silicon thin films is examined using harmonic lattice dynamics theory and the Lennard-Jones and Stillinger-Weber potentials. Film thicknesses ranging from 0.8 to 33.5 nm for argon and 0.4 to 8.6 nm for silicon are examined at a temperature of 0 K. Both reconstructed films and films built using the bulk unit cell are considered. Phonon dispersion curves for the in-plane direction and the density of states are computed from lattice dynamics and compared to predictions for a bulk system. The results from the lattice dynamics calculations are used to predict the thermal conductivities of the bulk and thin film structures.

Ab Initio Lattice Dynamics and Thermodynamics of MgS and Related II-VI Semiconductors in Zincblende Structure

2007 ◽  
Vol 561-565 ◽  
pp. 1907-1910 ◽  
Author(s):  
Shao Qing Wang
Keyword(s):  
Ab Initio ◽  
First Principles ◽  
Linear Response ◽  
Lattice Dynamics ◽  
Linear Thermal Expansion Coefficient ◽  
Phonon Dispersion ◽  
Linear Thermal Expansion ◽  
Dielectric Parameters ◽  
Function Calculation ◽  
Phonon Dispersion Relations

The lattice dynamics and thermodynamic properties of MgS and related II-VI compounds are studied by the first-principles linear-response function calculation in the framework of densityfunctional perturbation theory. The ab initio structural, mechanic and dielectric parameters of these phases are presented. From the theoretical phonon dispersion relations, the linear thermal expansion coefficient and its temperature dependence are calculated. The differences in structural and thermodynamic behaviors of these compounds are explained from their phonon dispersion characters.

Development of an Ab-initio Model of the Lattice Thermal Conductivity in Semiconductor Thin Films and Nanowires

2001 ◽  
Vol 677 ◽  
Author(s):  
Jie Zou ◽  
Alexander Balandin
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Lattice Thermal Conductivity ◽  
Phonon Dispersion ◽  
Interface Roughness ◽  
Semiconductor Thin Films ◽  
Predicted Values ◽  
Rough Boundaries ◽  
Good Agreement ◽  
Non Equilibrium

ABSTRACTA model for calculating the lattice thermal conductivity in semiconductor thin films and nanowires is developed. It is based on the solution of phonon Boltzmann equation and takes into account phonon dispersion modification due to confinement effects and non-equilibrium phonon redistribution. Phonon spatial confinement at the structure boundaries leads to modification of the acoustic phonon dispersion and corresponding drop in the mode-averaged group velocity. Scattering from rough boundaries and interfaces introduces a change in the non-equilibrium phonon distribution as compared to bulk. These effects lead to a reduction in the in-plane lattice thermal conductivity in both thin films and nanowires. The predicted values for the lattice thermal conductivity and their temperature and interface roughness dependence are in good agreement with available experimental data.

Quantitative Image Analysis of Fractal-like Thin Films of Organic Semiconductors

2018 ◽  
Author(s):  
Weikun Zhu ◽  
Erfan Mohammadi ◽  
Ying Diao
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Image Analysis ◽  
Fractal Dimension ◽  
Organic Semiconductors ◽  
Film Growth ◽  
Electronic Device ◽  
Significant Control ◽  
Semiconductor Thin Films ◽  
Two Parameters

Morphology modulation offers significant control over organic electronic device performance. However, morphology quantification has been rarely carried out via image analysis. In this work, we designed a MATLAB program to evaluate two key parameters describing morphology of small molecule semiconductor thin films: fractal dimension and film coverage. We then employ this program in a case study of meniscus-guided coating of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C<sub>8</sub>-BTBT) under various conditions to analyze a diverse and complex morphology set. The evolution of morphology in terms of fractal dimension and film coverage was studied as a function of coating speed. We discovered that combined fractal dimension and film coverage can quantitatively capture the key characteristics of C<sub>8</sub>-BTBT thin film morphology; change of these two parameters further inform morphology transition. Furthermore, fractal dimension could potentially shed light on thin film growth mechanisms.

Annealing Behavior with Thickness Hindered Nucleation in Small-Molecule Organic Semiconductor Thin Films

2019 ◽  
Vol 19 (7) ◽  
pp. 3777-3784
Author(s):  
Jakub Rozbořil ◽  
Katharina Broch ◽  
Roland Resel ◽  
Ondřej Caha ◽  
Filip Münz ◽  
...  
Keyword(s):  
Thin Films ◽  
Small Molecule ◽  
Organic Semiconductor ◽  
Annealing Behavior ◽  
Semiconductor Thin Films
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