Conductance Properties of Multilayered Silver-Mean and Period-Doubling Graphene Structures

2012 ◽  
Vol 1479 ◽  
pp. 117-123
Author(s):  
G. Rodríguez-Arellano ◽  
D. P. Juárez-López ◽  
J. Madrigal-Melchor ◽  
J. C. Martínez-Orozco ◽  
I. Rodríguez-Vargas
Keyword(s):  
Transfer Matrix ◽  
Period Doubling ◽  
Regular Sequence ◽  
Angle Of Incidence ◽  
Linear Regime ◽  
Silver Mean ◽  
Graphene Structures ◽  
Breaking Symmetry

ABSTRACTIn this work we alternate breaking-symmetry-substrates (BSS) and non-breaking-symmetry-substrates (NBSS) such as SiC and SiO2,following the Silver-Mean (MSMGS) and Period-Doubling (MPDGS) sequences. We implement the Transfer Matrix technique to calculate the transmittance and the linear-regime conductance as a function of the most relevant parameters of the multilayered graphene structures: energy and angle of incidence, widths of BSS and NBSS regions and the generation of the quasi-regular sequence. We analyze the main difference of the transmission and conductance properties between MSMGS and MPDGS.

Transmission properties of multilayered Period Doubling and Silver-Mean graphene structures

2012 ◽  
Vol 1371 ◽  
Author(s):  
G. Rodríguez-Arellano ◽  
D. P. Juárez-López ◽  
J. Madrigal-Melchor ◽  
R. Pérez-Álvarez ◽  
J. C. Martínez-Orozco ◽  
...  
Keyword(s):  
Graphene Sheet ◽  
Transfer Matrix ◽  
Period Doubling ◽  
Substitution Rule ◽  
Transmission Properties ◽  
Silver Mean ◽  
Propagation Properties ◽  
Graphene Structures ◽  
Breaking Symmetry

ABSTRACTWe present the propagation properties of Dirac-electrons in multilayered Period-Doubling (MPDGS) and Silver-Mean (MSMGS) graphene structures. The multilayered graphene structures are built arranging breaking and non-breaking symmetry substrates such as SiC and SiO2 following a given quasirregular substitution rule locating on them a graphene sheet. We have implemented the Transfer Matrix technique to calculate the transmittance of these multilayered graphene structures. This technique allows us to analyze readily the main differences of the transmission properties between MPDGS and MSMGS.

Analysis and Characterization of Surface Plasmon Enhancement of Light Absorption in Organic Solar Cells by the Transfer Matrix Method

2010 ◽  
Author(s):  
Francisco V. Rami´rez ◽  
Amador M. Guzma´n
Keyword(s):  
Solar Cells ◽  
Transfer Matrix ◽  
Organic Solar Cells ◽  
Transfer Matrix Method ◽  
Light Absorption ◽  
Matrix Method ◽  
Incident Light ◽  
Thick Layer ◽  
Physical Situation ◽  
Angle Of Incidence

Surface plasmons enhanced light absorption in organic solar cells based on a photoactive poly(2-methoxyl-5-(2-ethyl-hexyloxy)-1.4-phenylenevinylene):(6.6)-phenyl-C61-butyric-acid-methylester (MEH-PPV:PCBM), is studied by a computational model based on the transfer matrix method (TMM). Two physical situation with and without the bulk heterojunction film are considered and modeled on a 2D array of silver nanoparticles with a diameter of 40 nm embedded in a 50-nm-thick layer. The numerical simulation results that include optical properties in the wave length range of 350 and 750 nm, present qualitative and quantitative good agreement with previous results obtained by Duche et al (2009) in both conditions. Optical absorption results for incident light at an oblique angle of incidence are also obtained, with the purpose of determining the effect of the angle of incidence on the absorption properties.

DISPERSION OF ACOUSTIC PHONONS IN QUASIPERIODIC SUPERLATTICES

2004 ◽  
Vol 11 (06) ◽  
pp. 541-551 ◽  
Author(s):  
R. K. MISHRA ◽  
K. D. MISRA ◽  
R. P. TIWARI
Keyword(s):  
Dispersion Relation ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Acoustic Phonon ◽  
Multilayered Structure ◽  
Angle Of Incidence ◽  
Semiconducting Materials ◽  
Acoustic Phonons ◽  
Normal Angle

The aim of this work is to present an up-to-date study of acoustic phonon excitations that can propagate in multilayered structure with constituents arranged in quasiperiodic fashion. In this paper, the dispersion relation of acoustic phonons for the quasiperiodic superlattice using different semiconducting materials, with the help of transfer matrix method, is derived at normal angle of incidence. Calculation is presented for (a) Ge / Si and (b) Nb / Cu semiconductor superlattices from 5th to 9th generations and dispersion diagrams are plotted using the famous Kronning–Penny model obtained from the transfer matrix of the structure. The concept of allowed and forbidden bands with the help of these dispersion curves in various generations of Fibonacci superlattices and the relation between imaginary value of propagation vector and the existence of forbidden bands is demonstrated.

scholarly journals TRANSPORT CHARACTERISTICS NUMERICAL CALCULATION OF TWO-DIMENSIONAL NANOMATERIALS

2021 ◽  
Author(s):  
Vladislav Saveliev ◽  
Sofya Khazanova
Keyword(s):  
Numerical Calculation ◽  
Numerical Method ◽  
Transfer Matrix ◽  
Two Dimensional ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Graphene Structures

In this work, the current-voltage characteristics of graphene structures with an superperiod are calculated by the transfer matrix numerical method.

Study on Sound Absorption and Transmission Loss of Transversely Isotropic Multi Layers Porous Material

2010 ◽  
Author(s):  
Reza Keshavarz ◽  
Abdolreza Ohadi
Keyword(s):  
Absorption Coefficient ◽  
Transfer Matrix ◽  
Sound Absorption ◽  
Transmission Loss ◽  
Transversely Isotropic ◽  
Angle Of Incidence ◽  
Isotropic Layer ◽  
Acoustical Properties ◽  
Porous Layers ◽  
Total Displacement

In this work, acoustic wave propagation at oblique incidence in a multi layers material that consists of different layers such as air, homogenous and transversely isotropic porous layers is described. Transfer matrix method (TMM) is applied to compute acoustical properties of multilayer system. For transversely isotropic layer, the transfer matrix based on total displacement formulation of the Biot’s theory is used. Finally, for multi layers porous materials, variation of the sound absorption coefficient and transmission loss versus frequency and angle of incidence are determined. Analysis shows that transversely isotropic porous layers changes the absorption coefficient and improve the transmission loss.

scholarly journals A REMARK ON THE TRACE-MAP FOR THE SILVER MEAN SEQUENCE

2013 ◽  
Vol 27 (15) ◽  
pp. 1350107
Author(s):  
ILMAR GAHRAMANOV ◽  
ELMAR ASGEROV
Keyword(s):  
Electronic Properties ◽  
Recurrence Relation ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Matrix Approach ◽  
Transfer Matrices ◽  
Trace Map ◽  
Transfer Matrix Approach ◽  
Silver Mean

In this work, we study the Silver mean sequence based on substitution rules by means of a transfer-matrix approach. Using transfer-matrix method, we find a recurrence relation for the traces of general transfer-matrices which characterizes electronic properties of the quasicrystal in question. We also find an invariant of the trace-map.

Electron Channeling Patterns

1977 ◽  
Vol 35 ◽  
pp. 12-13
Author(s):  
David C. Joy
Keyword(s):  
Electron Diffraction ◽  
Incidence Angle ◽  
Photographic Plate ◽  
Diffraction Effect ◽  
Angle Of Incidence ◽  
Bulk Single Crystal ◽  
Time Resolved ◽  
Electron Channeling ◽  
Spatially Resolved ◽  
Large Bulk

Electron channeling patterns (ECP) were first found by Coates (1967) while observing a large bulk, single crystal of silicon in a scanning electron microscope. The geometric pattern visible was shown to be produced as a result of the changes in the angle of incidence, between the beam and the specimen surface normal, which occur when the sample is examined at low magnification (Booker, Shaw, Whelan and Hirsch 1967).A conventional electron diffraction pattern consists of an angularly resolved intensity distribution in space which may be directly viewed on a fluorescent screen or recorded on a photographic plate. An ECP, on the other hand, is produced as the result of changes in the signal collected by a suitable electron detector as the incidence angle is varied. If an integrating detector is used, or if the beam traverses the surface at a fixed angle, then no channeling contrast will be observed. The ECP is thus a time resolved electron diffraction effect. It can therefore be related to spatially resolved diffraction phenomena by an application of the concepts of reciprocity (Cowley 1969).

Electron-Channelling Patterns: Principles and Techniques

1976 ◽  
Vol 34 ◽  
pp. 400-401
Author(s):  
David C. Joy
Keyword(s):  
Crystal Structure ◽  
Electron Flux ◽  
Lattice Structure ◽  
Incident Beam ◽  
Bloch Wave ◽  
Crystalline Solid ◽  
Angle Of Incidence ◽  
Electron Channelling ◽  
Regular Arrangement ◽  
Backscattered Signals

In a crystalline solid the regular arrangement of the lattice structure influences the interaction of the incident beam with the specimen, leading to changes in both the transmitted and backscattered signals when the angle of incidence of the beam to the specimen is changed. For the simplest case the electron flux inside the specimen can be visualized as the sum of two, standing wave distributions of electrons (Fig. 1). Bloch wave 1 is concentrated mainly between the atom rows and so only interacts weakly with them. It is therefore transmitted well and backscattered weakly. Bloch wave 2 is concentrated on the line of atom centers and is therefore transmitted poorly and backscattered strongly. The ratio of the excitation of wave 1 to wave 2 varies with the angle between the incident beam and the crystal structure.

The Microstructure of Steatite (Protoenstatite)

1985 ◽  
Vol 43 ◽  
pp. 236-237
Author(s):  
W. E. Lee ◽  
A. H. Heuer
Keyword(s):  
High Frequency ◽  
Glass Ceramics ◽  
Magnesium Silicate ◽  
Beam Current ◽  
Glassy Matrix ◽  
Angle Of Incidence ◽  
X Ray ◽  
Mechanical And Electrical Properties ◽  
Argon Ions ◽  
High Temperature Polymorph

IntroductionTraditional steatite ceramics, made by firing (vitrifying) hydrous magnesium silicate, have long been used as insulators for high frequency applications due to their excellent mechanical and electrical properties. Early x-ray and optical analysis of steatites showed that they were composed largely of protoenstatite (MgSiO3) in a glassy matrix. Recent studies of enstatite-containing glass ceramics have revived interest in the polymorphism of enstatite. Three polymorphs exist, two with orthorhombic and one with monoclinic symmetry (ortho, proto and clino enstatite, respectively). Steatite ceramics are of particular interest a they contain the normally unstable high-temperature polymorph, protoenstatite.Experimental3mm diameter discs cut from steatite rods (∼10” long and 0.5” dia.) were ground, polished, dimpled, and ion-thinned to electron transparency using 6KV Argon ions at a beam current of 1 x 10-3 A and a 12° angle of incidence. The discs were coated with carbon prior to TEM examination to minimize charging effects.

On resolving fine periodic microstructures in the optical microscope

1989 ◽  
Vol 47 ◽  
pp. 364-365
Author(s):  
W.S. Putnam ◽  
C. Viney
Keyword(s):  
Liquid Crystalline ◽  
Numerical Aperture ◽  
Polarized Light ◽  
Normal Incidence ◽  
Optical Microscope ◽  
Angle Of Incidence ◽  
Resolution Limit ◽  
Crystalline Materials ◽  
Periodic Microstructures ◽  
Liquid Crystalline Materials

Many sheared liquid crystalline materials (fibers, films and moldings) exhibit a fine banded microstructure when observed in the polarized light microscope. In some cases, for example Kevlar® fiber, the periodicity is close to the resolution limit of even the highest numerical aperture objectives. The periodic microstructure reflects a non-uniform alignment of the constituent molecules, and consequently is an indication that the mechanical properties will be less than optimal. Thus it is necessary to obtain quality micrographs for characterization, which in turn requires that fine detail should contribute significantly to image formation.It is textbook knowledge that the resolution achievable with a given microscope objective (numerical aperture NA) and a given wavelength of light (λ) increases as the angle of incidence of light at the specimen surface is increased. Stated in terms of the Abbe resolution criterion, resolution improves from λ/NA to λ/2NA with increasing departure from normal incidence.

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