Influence on Band-Gap Overlap and Q-Factor of the Coaxial Bragg Structure with Double-Sinusoidal Ripples Operating at 0.35 THz Frequency

2020 ◽  
pp. 55-61
Author(s):  
Xue-Yong Ding ◽  
Hong-Rui Su ◽  
Yuan Wang ◽  
Lian-Sheng Wang
Keyword(s):  
Band Gap ◽  
Q Factor ◽  
Bragg Structure

Direct band gap germanium in high Q-factor cavities

2016 ◽  
Author(s):  
M. El Kurdi ◽  
A. Elbaz ◽  
M. Prost ◽  
A. Ghrib ◽  
R. Ossikovski ◽  
...  
Keyword(s):  
Band Gap ◽  
Q Factor ◽  
Direct Band Gap ◽  
High Q ◽  
Direct Band

scholarly journals Novel Fractal DGSs for Band-gap Filter with Improved Q-factor

2017 ◽  
Vol 26 (4) ◽  
pp. 992-998
Author(s):  
Y. Y. Gong ◽  
L. Wang ◽  
K. Wei ◽  
Z. L. Zhang
Keyword(s):  
Band Gap ◽  
Q Factor

scholarly journals Дефектная мода в СВЧ волноводных брэгговских структурах с металлическими штырями

2019 ◽  
Vol 89 (10) ◽  
pp. 1606
Author(s):  
Д.А. Усанов ◽  
А.В. Скрипаль ◽  
В.Н. Посадский ◽  
В.С. Тяжлов ◽  
А.В. Байкин
Keyword(s):  
Photonic Crystal ◽  
Frequency Response ◽  
Band Gap ◽  
Dynamic Range ◽  
Defect Mode ◽  
Response Functions ◽  
Bragg Structure ◽  
Microwave Photonic ◽  
Gap Characteristics ◽  
Wide Wall

AbstractA waveguide Bragg structure containing equidistant cylindrical pins that are galvanically coupled to a wide wall of the waveguide is used to implement frequency response functions characterized by the presence of a band gap. Characteristics of a defect mode of the microwave photonic crystal with a pin element as a defect with an n – i – p – i – n structure with controlled conductivity placed in the capacitive gap are experimentally studied and calculated. Controlled reflectance of a microwave signal with a dynamic range of greater than 50 dB is obtained at the frequency of the defect mode.

Effect of ripple taper on band-gap overlap in a coaxial Bragg structure operating at terahertz frequency

2012 ◽  
Vol 19 (9) ◽  
pp. 092105 ◽  
Author(s):  
Xue-Yong Ding ◽  
Hong-Fan Li ◽  
Zhen-Su Lv
Keyword(s):  
Band Gap ◽  
Terahertz Frequency ◽  
Bragg Structure

TEM and cathodoluminescence of precipitates in II-VI semiconductors

1988 ◽  
Vol 46 ◽  
pp. 488-489
Author(s):  
Joanna L. Batstone
Keyword(s):  
Crystal Growth ◽  
Band Gap ◽  
Local Strain ◽  
Wide Band ◽  
Optoelectronic Device ◽  
Wide Band Gap ◽  
Bulk Crystal Growth ◽  
Transmission Electron ◽  
Device Applications ◽  
Stoichiometry Control

Interest in II-VI semiconductors centres around optoelectronic device applications. The wide band gap II-VI semiconductors such as ZnS, ZnSe and ZnTe have been used in lasers and electroluminescent displays yielding room temperature blue luminescence. The narrow gap II-VI semiconductors such as CdTe and HgxCd1-x Te are currently used for infrared detectors, where the band gap can be varied continuously by changing the alloy composition x.Two major sources of precipitation can be identified in II-VI materials; (i) dopant introduction leading to local variations in concentration and subsequent precipitation and (ii) Te precipitation in ZnTe, CdTe and HgCdTe due to native point defects which arise from problems associated with stoichiometry control during crystal growth. Precipitation is observed in both bulk crystal growth and epitaxial growth and is frequently associated with segregation and precipitation at dislocations and grain boundaries. Precipitation has been observed using transmission electron microscopy (TEM) which is sensitive to local strain fields around inclusions.

Structural properties of GaAs/InGaAs/GaAs (001) and InGaAs/GaAs (001) heterostructures and correlation with electronic properties

1990 ◽  
Vol 48 (4) ◽  
pp. 602-603
Author(s):  
J.M. Bonar ◽  
R. Hull ◽  
R. Malik ◽  
R. Ryan ◽  
J.F. Walker
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Gaas Substrate ◽  
Critical Thickness ◽  
Lattice Mismatch ◽  
Band Offset ◽  
Misfit Dislocations ◽  
Gaas Substrates ◽  
Gaas Structure ◽  
Low X

In this study we have examined a series of strained heteropeitaxial GaAs/InGaAs/GaAs and InGaAs/GaAs structures, both on (001) GaAs substrates. These heterostructures are potentially very interesting from a device standpoint because of improved band gap properties (InAs has a much smaller band gap than GaAs so there is a large band offset at the InGaAs/GaAs interface), and because of the much higher mobility of InAs. However, there is a 7.2% lattice mismatch between InAs and GaAs, so an InxGa1-xAs layer in a GaAs structure with even relatively low x will have a large amount of strain, and misfit dislocations are expected to form above some critical thickness. We attempt here to correlate the effect of misfit dislocations on the electronic properties of this material.The samples we examined consisted of 200Å InxGa1-xAs layered in a hetero-junction bipolar transistor (HBT) structure (InxGa1-xAs on top of a (001) GaAs buffer, followed by more GaAs, then a layer of AlGaAs and a GaAs cap), and a series consisting of a 200Å layer of InxGa1-xAs on a (001) GaAs substrate.

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