scholarly journals Phase Characteristics of Models of GaAs Gyroelectric Waveguides with Temperature Sensitive Anisotropic Dielectric Layers in Case of One Layer

2018 ◽  
Vol 14 (2) ◽  
pp. 134-140
Author(s):  
Darius Plonis ◽  
Andrius Katkevičius ◽  
Diana Belova-Plonienė
Keyword(s):  
Dielectric Layer ◽  
Temperature Sensitive ◽  
Anisotropic Dielectric ◽  
Free Carriers ◽  
Coupled Mode ◽  
Wave Phase ◽  
Dielectric Layers ◽  
Partial Area ◽  
Density Of Electrons ◽  
Complex Dispersion

AbstractModels of open cylindrical multilayer gyroelectric-anisotropic-gyroelectric waveguides are presented in this paper. The influence of density of free carriers, temperature and the presence of the external dielectric layer on the wave phase characteristics of the models of n-GaAs waveguides has been evaluated. Differential Maxwell’s equations, coupled mode and partial area methods have been used to obtain complex dispersion equation of the models of gyroelectric-anisotropic-gyroelectric waveguides with or without the temperature sensitive external anisotropic dielectric layer. The analysis has shown that the phase characteristics are practically unchanged when the density of electrons is equal to N = (1017–5·1018) m−3, d/rs = 0, the changes of wave phase coefficients are obtained in the models of waveguides with the external anisotropic dielectric layer. The largest differences of wave phase coefficient are obtained when the density of electrons is N = 1021 m−3. The external dielectric layer improves the control of gyroelectric n-GaAs waveguides with temperature.

scholarly journals INVESTIGATION OF GYROELECTRIC WAVEGUIDES WITH ANISOTROPIC DIELECTRIC LAYER / GIROELEKTRINIŲ BANGOLAIDŽIŲ SU ANIZOTROPINIU DIELEKTRIKO SLUOKSNIU TYRIMAS

2014 ◽  
Vol 6 (2) ◽  
pp. 218-223
Author(s):  
Darius Plonis ◽  
Vacius Mališauskas
Keyword(s):  
Cross Section ◽  
Dielectric Layer ◽  
Hole Concentration ◽  
Circular Cross Section ◽  
Phase Shifters ◽  
Temperature Sensitive ◽  
Dielectric Waveguides ◽  
Differential Phase Shift ◽  
Anisotropic Dielectric ◽  
Open Circular

In this paper the open, circular cross-section cylindrical gyro- electric p-GaAs (semiconductor-dielectric) waveguides with temperature-sensitive anisotropic dielectric layer are investigated. The gyroelectric phase shifters without anisotropic dielectric layer are not effective. The anisotropic layer increases the mode HE11 differential phase shift to 1060° and 1250°, when temperature T = (125–200) K, N = 5∙1019 and N = 1020 m–3 respectively. Propagated mode HE11 in gyroelectric p-GaAs waveguides, the attenuation coefficient increases, increasing the concentration of holes. The anisotropic dielectric layer reduces the mode attenuation, it is appropriate to create gyroelectric mode phase shifters with a lower hole concentration and anisotropic dielectric layer. Tiriami atvirieji, apskritojo skerspjūvio cilindriniai, giroelektriniai p-GaAs (puslaidininkiniai-dielektriniai) bangolaidžiai su jautriais temperatūrai puslaidininkine šerdimi ir anizotropiniu dielektriko sluoksniu. Šis sluoksnis padidina hibridinių pagrindinio tipo HE11 bangų diferencinį fazės pokytį iki 1060° ir 1250°, kylant temperatūrai (125–200) K ruože, kai puslaidininkio skylučių koncentracija N atitinkamai yra 5∙1019 m–3 ir 1020 m–3. Giroelektriniuose p-GaAs bangolaidžiuose HE11 bangų silpimo koeficientas didėja, didinant skylučių koncentraciją, bet anizotropinio dielektriko sluoksnis mažina bangų silpimą. Todėl, kuriant temperatūra valdomus giroelektrinius bangų fazės keitiklius, tikslinga naudoti bangolaidžius su mažesnės koncentracijos skylutėmis ir jautriu temperatūrai anizotropinio dielektriko sluoksniu.

scholarly journals Investigation Of Gyroelectric Waveguides With Anisotropic Dielectric Layer

2014 ◽  
Vol 6 (2) ◽  
pp. 218-223
Author(s):  
Darius Plonis ◽  
Vacius Mališauskas
Keyword(s):  
Dielectric Layer ◽  
Anisotropic Dielectric

The effect of inorganic/organic dual dielectric layers on the morphology and performance of n-channel OFETs

2016 ◽  
Vol 18 (17) ◽  
pp. 12163-12168 ◽  
Author(s):  
Anamika Kalita ◽  
Anamika Dey ◽  
Parameswar Krishnan Iyer
Keyword(s):  
Dielectric Layer ◽  
Dielectric Layers ◽  
Naphthalene Diimide ◽  
And Performance

Excellent n-channel behavior was observed for cyclohexyl substituted naphthalene diimide with the highest μe value of 0.08 cm2 V−1 s−1, VTH as low as 0.5 V and ION/IOFF ratio of 104 under vacuum with a Al2O3/PVA dual dielectric layer.

A novel polymer as a functional dielectric layer for OTFTs to improve the grain size of the pentacene semiconductor

2016 ◽  
Vol 7 (11) ◽  
pp. 2143-2150 ◽  
Author(s):  
Yao Li ◽  
He Wang ◽  
Xuesong Wang ◽  
Zuosen Shi ◽  
Donghang Yan ◽  
...  
Keyword(s):  
Thin Film ◽  
Grain Size ◽  
Charge Carrier ◽  
Dielectric Layer ◽  
Thin Film Transistors ◽  
Carrier Mobility ◽  
Charge Carrier Mobility ◽  
Single Variable ◽  
Dielectric Layers ◽  
The Relationship

A series of novel polymers as functional dielectric layers for pentacene thin-film transistors was synthesized and investigated to explore the relationship between the grain size and the charge carrier mobility with a single variable.

Detection of Crystallographic Defects in 3C-SiC by Micro-Raman and Micro-PL Analysis

2017 ◽  
Vol 897 ◽  
pp. 303-306 ◽  
Author(s):  
Grazia Litrico ◽  
Nicolò Piluso ◽  
Francesco La Via
Keyword(s):  
High Power ◽  
Longitudinal Optical ◽  
Epitaxial Films ◽  
Raman Shift ◽  
Extended Defects ◽  
Free Carriers ◽  
Coupled Mode ◽  
Pl Emission ◽  
A New Technique ◽  
Crystallographic Defects

A new technique with micro-Raman and micro-PL analysis is proposed to detect defects in 3C-SiC epitaxial films. The high-power of an above band-gap laser is used to increase locally the free carriers density in un-doped epitaxial material (n < 1016 cm-3). The electronic plasma couples with the longitudinal optical (LO) Raman mode determining the so-called LOPC effect. The Raman shift of the LO phonon-plasmon-coupled mode (LOPC) changes as the free carriers density is modified. Crystallographic defects induce a modification of the free carriers density determining a change in the Raman shift of LO mode and in the PL emission from the 3C-SiC gap. Thus we suppose that the results observed are connected to crystallographic defects and we propose this technique as a methodology to analyze extended defects in 3C-SiC material because a detailed study of defects in 3C-SiC has not yet been performed.

Fatigue and Aging in Sol-Gel Derived PZT Thin Films

1990 ◽  
Vol 200 ◽  
Author(s):  
W.H. Shepherd
Keyword(s):  
Thin Films ◽  
Initial Period ◽  
Sol Gel ◽  
Temperature Sensitive ◽  
Physical Processes ◽  
Pzt Thin Films ◽  
Fatigue Process ◽  
Dielectric Layers ◽  
Pzt Films ◽  
Internal Bias

ABSTRACTTypical fatigue and aging characteristics are reported for thin PZT films prepared using sol-gels. The fatigue process occurs in two steps. There is an initial period, during which the domain matrix of the as formed film is restructured by the cycling and the polarization generally increases, followed by a period in which the polarization decays. The polarization decay may be due, in part, to the formation of dielectric layers at the electrodes. The effects of voltage and temperature on fatigue are reported. Aging is examined as a function of temperature. Measurements of internal bias fields do not support the view that they are the primary cause of aging. Neither fatigue nor aging are temperature sensitive making identification of specific physical processes difficult.

Rutherford Backscattering Spectrometry Analysis of Growth Rate and Activation Energy for Self-formed Ti-rich Interface Layers in Cu(Ti)/Low-k Samples

2009 ◽  
Vol 1156 ◽  
Author(s):  
Kazuyuki Kohama ◽  
Kazuhiro Ito ◽  
Kenichi Mori ◽  
Kazuyoshi Maekawa ◽  
Yasuharu Shirai ◽  
...  
Keyword(s):  
Activation Energy ◽  
Dielectric Layer ◽  
Rutherford Backscattering Spectrometry ◽  
High Vacuum ◽  
Formation Enthalpy ◽  
Interface Layer ◽  
Rutherford Backscattering ◽  
Ultra High Vacuum ◽  
Dielectric Layers ◽  
Interface Layers

AbstractA new fabrication technique to prepare ultra-thin barrier layers for nano-scale Cu wires was proposed in our previous studies. Ti-rich layers formed at the Cu(Ti)/dielectric-layer interfaces consisted of crystalline TiC or TiSi and amorphous Ti oxides. The primary control factor for Ti-rich interface layer composition was the C concentration in the dielectric layers rather than the formation enthalpy of the Ti compounds. To investigate Ti-rich interface layer growth in Cu(Ti)/dielectric-layer samples annealed in ultra high vacuum, Rutherford Backscattering Spectrometry (RBS) was employed in the present study. Ti peaks were obtained only at the interface for all the samples. Molar amounts of Ti atoms segregated to the interface (n) were estimated from Ti peak areas. The n value was defined by n = Z·exp(-E/RT) · tm, where Z is a preexponential factor and E the activation energy for the reaction. The Z, E, and m values were estimated from plots of log n vs log t and log n vs 1/T. The m values are similar in all the samples. The E values for Ti atoms reacting with the dielectric layers containing carbon (except SiO2) tended to decrease with decreasing C concentration (decreasing k), while reaction rate coefficients (Z·exp(-E/RT)) were insensitive to C concentration in the dielectric layers. These factors lead to conclusion that growth of the Ti-rich interface layers is controlled by chemical reactions of the Ti atoms with the dielectric layers represented by the Z and E values, rather than diffusion in the Ti-rich interface layers.

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