scholarly journals MAGNETOACTIVE P-GE ROD WAVEGUIDE LOSS ANALYSIS ON THE CONCENTRATION OF TWO COMPONENT HOLE CHARGE CARRIERS / CILINDRINIŲ GIROELEKTRINIŲ P-GE BANGOLAIDŽIŲ NUOSTOLIŲ PRIKLAUSOMYBĖS NUO DVIEJŲ RŪŠIŲ KRŪVININKŲ KONCENTRACIJOS TYRIMAS

2012 ◽  
Vol 4 (1) ◽  
pp. 77-80
Author(s):  
Artūras Bubnelis
Keyword(s):  
Heavy Hole ◽  
Hole Concentration ◽  
Charge Carriers ◽  
Dispersion Characteristics ◽  
Main Mode ◽  
Higher Modes ◽  
Loss Analysis ◽  
Waveguide Loss ◽  
Hole Charge ◽  
Two Component

A new algorithm is utilized to examine the phase and attenuation constants of open dissipative epsilon- and (or) mu-gyrotropic rod waveguides. Our algorithm allows analyzing the waveguides made of materials having very high losses. The dispersion characteristics of p-Ge with a waveguide of two component hole charge carriers are calculated when the ratio of heavy hole concentration in the material is equal to 5%, 50% and 95% of the total free carrier concentration. The effective mass of p-Ge heavy and light holes are 0.279me and 0.043me respectively. The dispersion characteristics of the main and eight higher modes are presented in the paper. The transformation of higher hybrid modes at some heavy hole concentrations can be noticed. Waveguide broad bandwidth can be considerably extended due to the fact that the losses of higher modes are larger in comparison to those of the main mode at certain heavy hole concentration. Santrauka Darbe pateikiami dviejų rūšių krūvininkų (lengvųjų ir sunkiųjų skylučių) puslaidininkinių p-Ge giroelektrinių bangolaidžių, kuriuos veikia B 1 0 = r T indukcijos nuolatinis išilginis magnetinis laukas, dispersinių charakteristikų skaičiavimo rezultatai, įvertinant nuostolius bangolaidyje. Skaičiavimo algoritmas leidžia tirti bangolaidžius, pagamintus iš medžiagų, atnešančių labai didelius nuostolius. Tiriamos 1 mm spindulio bangolaidžių dažninės charakteristikos 5–200 GHz dažnių ruože. Laisvųjų krūvininkų koncentracija bangolaidyje yra N = 5·1019 m–3. Nustatoma nuostolių priklausomybė nuo sunkiųjų skylučių krūvininkų koncentracijos Nh, esant trims skirtingoms sunkiųjų skylučių koncentracijoms, kai Nh sudaro 5 %, 50 % ir 95 % nuo visų krūvininkų koncentracijos N bangolaidyje.

The Magnetoactive p-Ge Rod Waveguide Loss Analysis on the Concen-tration of Two Component Hole Charge Carriers

1970 ◽  
Vol 110 (4) ◽  
pp. 53-56 ◽  
Author(s):  
L. Nickelson ◽  
A. Bubnelis ◽  
A. Baskys ◽  
R. Navickas
Keyword(s):  
Free Carrier ◽  
Charge Carriers ◽  
Dispersion Characteristics ◽  
Main Mode ◽  
Loss Analysis ◽  
Waveguide Loss ◽  
Hole Charge ◽  
Two Component ◽  
Mode Loss ◽  
Very High

In this work are examined the phase and attenuation constants of open magnetoactive p-Ge rod waveguides. Our algorithm allows ana-lyzing the very high waveguide losses. Dispersion characteristics of p-Ge with two component hole charge carriers waveguide are calculated when the ratio of heavy holes' concentration in the material is equal to 10%, 30% and 90% of the total free carrier concentration. Dispersion characteristics of the main helicon and eight higher helicon modes are presented here. There are the degeneration and the transformation of higher hybrid modes at some heavy holes' concentrations. The waveguide broadbandwidth can be considerably extended due to the fact that the losses of the higher modes are considerably larger in comparisons to the main mode loss at the certain heavy holes' concentration. Ill. 6, bibl. 12 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.110.4.286

The dependence of open cylindrical magnetoactive p-Ge and p-Si plasma waveguide mode cutoff frequencies on hole concentrations

2009 ◽  
Vol 75 (1) ◽  
pp. 35-51 ◽  
Author(s):  
L. NICKELSON ◽  
S. ASMONTAS ◽  
V. MALISAUSKAS ◽  
R. MARTAVICIUS
Keyword(s):  
Hole Concentration ◽  
Cutoff Frequency ◽  
Charge Carriers ◽  
Plasma Waveguide ◽  
Main Mode ◽  
Cutoff Frequencies ◽  
Hole Charge ◽  
Two Component ◽  
Open Circular ◽  
Mode Cutoff

AbstractIn this article we give the solution of Maxwell's equations for the open circular cylindrical magnetoactive semiconductor plasma (-gyrotropy) waveguides. We describe the method that allowed us to arrive at a dispersion equation for the electrodynamical analyses of open circular cylindrical plasma (OCCP) waveguides. We numerically investigate the main and two higher modes' dispersion characteristics of p-Ge and p-Si waveguides placed in an external constant longitudinal magnetic field at several concentrations of two component hole charge carriers. We analyse the cutoff frequency and other electrodynamical characteristics of helicon modes with the left-handed (e+iϕ) circular polarization. We discover that the cutoff frequencies of the main mode and the working frequency range of OCCP p-Ge and p-Si waveguides are moving continuously towards the direction of higher frequencies when the hole concentration is increasing. We determine that the central frequency of the p-Si plasma waveguide is higher and its broadbandwidth is larger compared with the analogical p-Ge waveguide. We also numerically investigate the helicon mode cutoff frequencies of the infinitive p-Ge and p-Si plasma at several concentrations of two component hole charge carriers. We compare the cutoff frequencies of the helicon modes propagating in the infinite plasma and in the OCCP waveguides.

scholarly journals GYROTROPIC WAVEGUIDES ANALYSIS

2010 ◽  
Vol 2 (1) ◽  
pp. 117-121
Author(s):  
Darius Plonis
Keyword(s):  
Wide Frequency Range ◽  
Phase Shifters ◽  
Microwave Devices ◽  
Dispersion Characteristics ◽  
Frequency Range ◽  
Main Mode ◽  
Semiconductor Waveguides ◽  
Higher Modes ◽  
Working Frequency ◽  
Draw Conclusion

An algorithm and program in MATLAB® for the dispersions characteristics calculation in wide frequency range 15–100 GHz was created. We calculated and analyzed in ferrite and semiconductor waveguides, then they are longitudinally magnetized, also we analyzed main mode HE11 and higher modes EH11 and HE12 dispersion characteristics. We analyzed semiconductor p-Ge, p-GaAs waveguides and compared gyromagnetic and gyroelectric waveguides bandwidth with dielectrical layer. We decided that outer dielectrical layer changed waveguide working frequency range. We draw conclusion that it can be used for made microwave devices for example phase shifters or other devices.

The Dynamic Ultrasound Influence on the Diffusion and Drift of the Charge Carriers in Silicon p-n Structures

2007 ◽  
Vol 994 ◽  
Author(s):  
Roman M. Burbelo ◽  
Oleg Y. Olikh ◽  
Mark K. Hinders
Keyword(s):  
Acoustic Waves ◽  
Hole Concentration ◽  
Acoustic Vibration ◽  
Ultrasonic Waves ◽  
Charge Carriers ◽  
Equilibrium Conditions ◽  
Defective Structure ◽  
Semiconductor Structures ◽  
Ultrasound Frequency ◽  
Non Equilibrium

AbstractNowadays much attention is given to the ultrasound influence on electrophysical properties and defective structure of semiconductors and semiconductor structures [1,2]. In particular, a big interest is caused by the processes which take place in the material under non-equilibrium conditions, caused by the acoustic vibration [2]. This paper is devoted to the study of the ultrasonic waves dynamic influence (in situ) on the processes of the charge transport in a silicon solar sell.The silicon structures with p-n-transition received by phosphorus ions implantation in a surface layer of Si:B plate have been chosen as the research objects. Transition is located at 0,5 microns depth from surface, n-layer electron concentration is 1019 cm−3, hole concentration is 1.3×1015 cm−3. The specified structures I-V characteristics are measured under ultrasonic fluctuations excitation conditions. The researches were carried out both without external illumination as well as under external illumination. In the latter case, additional carriers photogeneration occurred both at the p-n-transition region and at the p-area depth. Longitudinal acoustic waves were excited in structures with help of LiNbO3 transducer; the ultrasound frequency is 4.1 and 13.6 MHz; the acoustic power is up to 3 W/cm2.It is revealed, that the changes of diffusion parameters take place at the non-equilibrium conditions caused by ultrasonic lading. These changes are shown in photocurrent rising. Photocurrent increase reached up to 15 %, which corresponds to 2 times diffusion length increasing approximately. Also the essential (up to 40 %) acoustostimulated decreasing of the p-n-transition saturation current is revealed. The characteristic time of the observable effects is level with tens minutes. It is established, that dependence of the dynamic changes on ultrasound power is nonlinear. It is shown, that efficiency of an acoustostimulated influences raises with an ultrasound frequency.The analysis has shown that observable effects are connected with non-equilibrium processes of defects ionization and reorientation at an acoustic field. It specifies an opportunity of a dynamic management of a charge carriers distribution processes in semiconductor structures by ultrasonic waves.

Higher modes of seismic surface waves: Propagation in Eurasia

1966 ◽  
Vol 56 (6) ◽  
pp. 1227-1239 ◽  
Author(s):  
Stuart Crampin
Keyword(s):  
Surface Waves ◽  
Rapid Change ◽  
Phase Relationship ◽  
Dispersion Characteristics ◽  
Constructive Interference ◽  
Higher Modes ◽  
Mountain Ranges ◽  
Seismic Surface Waves ◽  
Wave Trains ◽  
Waves Propagation

Abstract Second Love and second Rayleigh modes are found to propagate in Eurasia across many different structures; the continent is divided into regions where these higher modes have the same dispersion characteristics. The condition for constructive interference breaks down only when the second modes cross areas of rapid change at oceanic-continental boundaries and under some mountain ranges. There are many paths in Eurasia where the second Love and Rayleigh modes have the same dispersion, and along these paths the two wave trains have a constant phase relationship, suggesting that the modes have some form of elastic linkage.

scholarly journals Электрофизические и фотолюминесцентные исследования сверхрешeток \LT-GaAs/GaAs : Si\, выращенных методом молекулярно-лучевой эпитаксии на подложках GaAs с ориентацией (100) и (111)А

2019 ◽  
Vol 53 (2) ◽  
pp. 258
Author(s):  
Г.Б. Галиев ◽  
Е.А. Климов ◽  
А.Н. Клочков ◽  
В.Б. Копылов ◽  
C.C. Пушкарев
Keyword(s):  
Growth Temperature ◽  
Hole Concentration ◽  
Charge Carriers ◽  
Photoluminescence Spectra ◽  
Type Conductivity ◽  
Semiconductor Structures ◽  
Higher Temperature ◽  
P Type ◽  
First Time ◽  
Lt Gaas

AbstractThe results of studying semiconductor structures proposed for the first time and grown, which combine the properties of LT-GaAs with p -type conductivity upon doping with Si, are presented. The structures are {LT-GaAs/GaAs:Si} superlattices, in which the LT-GaAs layers are grown at a low temperature (in the range 280–350°C) and the GaAs:Si layers at a higher temperature (470°C). The p -type conductivity upon doping with Si is provided by the use of GaAs(111)A substrates and the choice of the growth temperature and the ratio between As_4 and Ga fluxes. The hole concentration steadily decreases, as the growth temperature of LT-GaAs layers is lowered from 350 to 280°C, which is attributed to an increase in the roughness of interfaces between layers and to the formation of regions depleted of charge carriers at the interfaces between the GaAs:Si and LT-GaAS layers. The evolution of the photoluminescence spectra at 77 K under variations in the growth temperature of LT-GaAs is interpreted as a result of changes in the concentration of Ga_As and V _Ga point defects and Si_Ga– V _Ga, V _As–Si_As, and Si_As–Si_Ga complexes.

scholarly journals Descriptors for Electron and Hole Charge Carriers in Metal Oxides

2019 ◽  
Author(s):  
Daniel Davies ◽  
Christopher Savory ◽  
Jarvist Moore Frost ◽  
David Scanlon ◽  
Benjamin Morgan ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Metal Oxides ◽  
Small Polaron ◽  
High Mobility ◽  
Charge Carriers ◽  
Oxide Semiconductors ◽  
Hole Charge ◽  
Electron Phonon Coupling ◽  
Carrier Effective Mass ◽  
P Type

<div> <div> <div> <p>Metal oxides can act as insulators, semiconductors or metals depending on their chemical composition and crystal structure. Metal oxide semiconductors, which support equilibrium populations of electron and hole charge carriers, have widespread applications including batteries, solar cells, and display technologies. It is often difficult to predict in advance whether these materials will exhibit localized or delocalized charge carriers upon oxidation or reduction. We combine data from first-principles calculations of the electronic structure and dielectric response of 214 metal oxides to predict the energetic driving force for carrier localization and transport. We assess descriptors based on the carrier effective mass, static polaron binding energy, and Frohlich electron–phonon coupling. Numerical analysis allows us to assign p and n type transport of a metal oxide to three classes: (i) band transport with high mobility; (ii) small polaron transport with low mobility; and (iii) intermediate behaviour. The results of this classification agree with observations regarding carrier dynamics and lifetimes and are used to predict 10 candidate p-type oxides. </p> </div> </div> </div>

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