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Ahmed N. Alshembari - One of the best experts on this subject based on the ideXlab platform.

  • تطبيقات طرق الجبر الخطي Ù�ÙŠ حل الموجات الكهرومغناطيسية Ù�ÙŠ أدلة موجية متعددة الطبقات
    الجامعة الإسلامية - غزة, 2017
    Co-Authors: Ahmed N. Alshembari
    Abstract:

    In this thesis, we have implemented a case of polarization of the electromagnetic field (hybrid modes) which includes both transverse electric field and transverse magnetic field. The purpose of applying this case is to find a transfer matrix, which depends on analytical and mathematical bases. Solar cells provide a renewable and clean energy by converting the sunlight to electricity and it is considered as a dependable energy source. Also, a new waveguide solar cell structure has been designed and investigated as a solar cell model. The designed waveguide structure contains four layers, the first layer is Air, the second is Aluminium oxynitride , the third is Iron- indium Gallium Arsenide Phosphide (Fe-InGaAsP), and the last layer is Silicon is a Substrate, has been used in order to improve the absorption of light. In this thesis, theoretical and analytical investigations of electromagnetic wave propagation through the proposed structure have been achieved. Transverse electric polarized plane waves are normally and obliquely incident upon the proposed structure. The electromagnetic transmitted, reflected and by absorbed versus of the incident frequency has been computed numerically using formulated reflection and transmission coefficients. In computations, the effect of changing the values of absorbing factor, thicknesses of slabs, and angles of incidence has been studied. We used MAPLE software to run the simulation of the proposed waveguide structure. This work has shown excellent results for high transmission of the incident waves for certain frequency bands. Hence, the studied structure would be promising to be utilized in the field of solar cells. Keywords: Linear Algebra, Electromagnetic waves, Multilayer waveguides, Hybrid mode, Transfer Matrix, Solar Cells�ي هذه الأطروحة قمنا بتطبيق حالة من حالات استقطاب المجال الكهرومغناطيسي وهي حالة الهجين المستعرض والتي تشمل كلا من المجال الكهربائي المستعرض و المجال المغناطيسي المستعرض معا, حيث تم تطبيق هذه الحالة �ي إيجاد مص�و�ة التحويل التي يعتمد �ي إيجادها على أساس رياضي تحليلي. و يشمل البحث أيضا على تحليل أحد الأبحاث العلمية ذات صلة بالموضوع من خلال تطبيق النتائج التي تم الحصول عليها �ي هذا البحث. قمنا أيضا بدراسة نموذج لتركيب خلية شمسية يحتوي على أربع طبقات, الطبقة الأولى هواء و الثانية تحتوي على مادة اوكسي نيترات الألومنيوم و الثالثة هي خليط من مادة الحديد و الجاليوم و ال�س�ور والانديوم و الزرنيخ, و الطبقة الأخيرة تحتوي على مادة السيلكون وذلك لتحسين امتصاص الضوء. حيث, يتناول هذا البحث دراسة نظرية و تحليلية لاختراق الأمواج الكهرومغناطيسية عبر التركيب المقترح, ويركز على دراسة قدرات الانعكاس و الن�اذ بالإضا�ة للامتصاص عبر التركيب لموجة مستوية و كهربية مستعرضة تسقط بشكل عمودي و حتى مائل. حيث تم حساب قدرات الن�اذ, الانعكاس و الامتصاص عدديا كإقترانات �ي التردد الساقط من خلال إيجاد صيغ رياضية لمعاملات الانعكاس و الن�اذ, و أثناء العمليات الحسابية تم دراسة تأثير تغيير القيم العددية لكل من معامل الامتصاص وسمك الطبقة وزاوية السقوط للموجة. كذلك قمنا باستخدام برامج حاسوبية لمحاكاة النموذج المدروس ورسم العلاقات بين المتغيرات المدروسة. كما و تتميز الخلايا الشمسية بقدرتها على تو�ير طاقة متجددة و نظي�ة, يعتمد مبدأ عملها على تحويل الطاقة الضوئية إلى طاقة كهربائية . تواجه الخلايا الشمسية العديد من التحديات منها التكل�ة العالية نسبيا عند التصنيع و مدى ال�عالية وذلك مقارنة بغيرها من البدائل. مواجهة هذه التحديات مهم جدا لجعل الخلايا الشمسية مصدرا يعتمد عليه للحصول على الطاقة. �ي هذا العمل تم الحصول على نتائج ممتازة لن�اذ كبير عبر التركيب لموجات ساقطة عليه بترددات معينة الأمر الذي يجعل منه تركيبا واعداً �ي المستقبل ليتم توظي�ه �ي حقل الخلايا الشمسية. كلمات م�تاحية: الجبر الخطي �ي ال�يزياء, الموجات الكهرومغناطيسية, الموجه الموجي , الهجين المستعرض, مص�و�ة التحويل, الخلايا الشمسية

احمد نصر الشمباري - One of the best experts on this subject based on the ideXlab platform.

  • تطبيقات طرق الجبر الخطي Ù�ÙŠ حل الموجات الكهرومغناطيسية Ù�ÙŠ أدلة موجية متعددة الطبقات
    الجامعة الإسلامية - غزة, 2017
    Co-Authors: احمد نصر الشمباري
    Abstract:

    In this thesis, we have implemented a case of polarization of the electromagnetic field (hybrid modes) which includes both transverse electric field and transverse magnetic field. The purpose of applying this case is to find a transfer matrix, which depends on analytical and mathematical bases. Solar cells provide a renewable and clean energy by converting the sunlight to electricity and it is considered as a dependable energy source. Also, a new waveguide solar cell structure has been designed and investigated as a solar cell model. The designed waveguide structure contains four layers, the first layer is Air, the second is Aluminium oxynitride , the third is Iron- indium Gallium Arsenide Phosphide (Fe-InGaAsP), and the last layer is Silicon is a Substrate, has been used in order to improve the absorption of light. In this thesis, theoretical and analytical investigations of electromagnetic wave propagation through the proposed structure have been achieved. Transverse electric polarized plane waves are normally and obliquely incident upon the proposed structure. The electromagnetic transmitted, reflected and by absorbed versus of the incident frequency has been computed numerically using formulated reflection and transmission coefficients. In computations, the effect of changing the values of absorbing factor, thicknesses of slabs, and angles of incidence has been studied. We used MAPLE software to run the simulation of the proposed waveguide structure. This work has shown excellent results for high transmission of the incident waves for certain frequency bands. Hence, the studied structure would be promising to be utilized in the field of solar cells. Keywords: Linear Algebra, Electromagnetic waves, Multilayer waveguides, Hybrid mode, Transfer Matrix, Solar Cells�ي هذه الأطروحة قمنا بتطبيق حالة من حالات استقطاب المجال الكهرومغناطيسي وهي حالة الهجين المستعرض والتي تشمل كلا من المجال الكهربائي المستعرض و المجال المغناطيسي المستعرض معا, حيث تم تطبيق هذه الحالة �ي إيجاد مص�و�ة التحويل التي يعتمد �ي إيجادها على أساس رياضي تحليلي. و يشمل البحث أيضا على تحليل أحد الأبحاث العلمية ذات صلة بالموضوع من خلال تطبيق النتائج التي تم الحصول عليها �ي هذا البحث. قمنا أيضا بدراسة نموذج لتركيب خلية شمسية يحتوي على أربع طبقات, الطبقة الأولى هواء و الثانية تحتوي على مادة اوكسي نيترات الألومنيوم و الثالثة هي خليط من مادة الحديد و الجاليوم و ال�س�ور والانديوم و الزرنيخ, و الطبقة الأخيرة تحتوي على مادة السيلكون وذلك لتحسين امتصاص الضوء. حيث, يتناول هذا البحث دراسة نظرية و تحليلية لاختراق الأمواج الكهرومغناطيسية عبر التركيب المقترح, ويركز على دراسة قدرات الانعكاس و الن�اذ بالإضا�ة للامتصاص عبر التركيب لموجة مستوية و كهربية مستعرضة تسقط بشكل عمودي و حتى مائل. حيث تم حساب قدرات الن�اذ, الانعكاس و الامتصاص عدديا كإقترانات �ي التردد الساقط من خلال إيجاد صيغ رياضية لمعاملات الانعكاس و الن�اذ, و أثناء العمليات الحسابية تم دراسة تأثير تغيير القيم العددية لكل من معامل الامتصاص وسمك الطبقة وزاوية السقوط للموجة. كذلك قمنا باستخدام برامج حاسوبية لمحاكاة النموذج المدروس ورسم العلاقات بين المتغيرات المدروسة. كما و تتميز الخلايا الشمسية بقدرتها على تو�ير طاقة متجددة و نظي�ة, يعتمد مبدأ عملها على تحويل الطاقة الضوئية إلى طاقة كهربائية . تواجه الخلايا الشمسية العديد من التحديات منها التكل�ة العالية نسبيا عند التصنيع و مدى ال�عالية وذلك مقارنة بغيرها من البدائل. مواجهة هذه التحديات مهم جدا لجعل الخلايا الشمسية مصدرا يعتمد عليه للحصول على الطاقة. �ي هذا العمل تم الحصول على نتائج ممتازة لن�اذ كبير عبر التركيب لموجات ساقطة عليه بترددات معينة الأمر الذي يجعل منه تركيبا واعداً �ي المستقبل ليتم توظي�ه �ي حقل الخلايا الشمسية. كلمات م�تاحية: الجبر الخطي �ي ال�يزياء, الموجات الكهرومغناطيسية, الموجه الموجي , الهجين المستعرض, مص�و�ة التحويل, الخلايا الشمسية.Linear AlgebraElectromagnetic wavesMultilayer waveguidesHybrid modeTransfer MatrixSolar Cell

Anindita Karroy - One of the best experts on this subject based on the ideXlab platform.

  • guided wave acousto optic bragg diffraction in indium Gallium Arsenide Phosphide waveguides
    Applied Physics Letters, 1997
    Co-Authors: C. S. Tsai, Anindita Karroy
    Abstract:

    Theoretical and experimental studies on guided-wave acousto-optic (AO) Bragg diffraction in a composite indium Gallium Arsenide Phosphide (InGaAsP) planar waveguide were carried out. In this letter, the experimental results of the excitation and propagation of a 〈110〉-directed surface acoustic wave (SAW) at the center frequency of 167 MHz, and the AO Bragg diffraction at a 1.31 micron wavelength in In0.22Ga0.78As0.47P0.53 waveguide are reported. An AO Bragg diffraction efficiency as high as 14% was achieved at an acoustic drive power of 8.5 mW with an interaction length (transducer aperture) of only 1.0 mm. Two orders of magnitude improvement in the Bragg diffraction efficiency versus rf drive power should be achievable by the optimization of the SAW transducer and the optical waveguide parameters.

C. S. Tsai - One of the best experts on this subject based on the ideXlab platform.

  • guided wave acousto optic bragg diffraction in indium Gallium Arsenide Phosphide waveguides
    Applied Physics Letters, 1997
    Co-Authors: C. S. Tsai, Anindita Karroy
    Abstract:

    Theoretical and experimental studies on guided-wave acousto-optic (AO) Bragg diffraction in a composite indium Gallium Arsenide Phosphide (InGaAsP) planar waveguide were carried out. In this letter, the experimental results of the excitation and propagation of a 〈110〉-directed surface acoustic wave (SAW) at the center frequency of 167 MHz, and the AO Bragg diffraction at a 1.31 micron wavelength in In0.22Ga0.78As0.47P0.53 waveguide are reported. An AO Bragg diffraction efficiency as high as 14% was achieved at an acoustic drive power of 8.5 mW with an interaction length (transducer aperture) of only 1.0 mm. Two orders of magnitude improvement in the Bragg diffraction efficiency versus rf drive power should be achievable by the optimization of the SAW transducer and the optical waveguide parameters.

Brunemeier, Paul Edward - One of the best experts on this subject based on the ideXlab platform.

  • Liquid phase epitaxial growth and heterointerface characteristics of long-wavelength indium Gallium Arsenide Phosphide heterostructures
    2026
    Co-Authors: Brunemeier, Paul Edward
    Abstract:

    Data are presented that demonstrate that the InGaAsP quaternary grown by constant temperature liquid phase epitaxy on InP substrate can, under certain growth conditions, exhibit considerably narrower diffraction profile half-widths than previously reported. The double crystal x-ray diffraction half-width is a relatively new assay of crystalline alloy compositional homogeneity, and the 13 arc sec value presented here for InGaAsP may represent a lower limit for the homogeneity of this material system, as a result of alloy effects. Bandgap and lattice constant data are given that characterize the transient composition that occurs at the onset of liquid phase epitaxial growth of InGaAsP on InP substrates. This compositional inhomogeneity, a region of significantly different bandgap and lattice constant than that of the remainder of the layer, is a result of the extreme non-equilibirum conditions that exist in the first milliseconds of growth. The data presented here indicate a shift in mismatch and bandgap of " 16xlO-4 and (20 meV t respectively, as a result of the transient composition. These results permit a calculation of the changes in the individual solidus atomic species, which illuminate some aspects of incorporation kinetic effects. Transmission electron microscopy (TEM) data are presented that characterize the interfacial "damage" that arises during the liquid phase epitaxial growth of an arsenic-poor InGaAsP quatenary on a previously grown iv arsenic-rich layer. This "damage" takes the form of a ragged heterointerface with extensive dislocations and is observed for Some of the heterostructures examined. Other heterostructures are demonstrated that yield high-quality interfaces in TEM, which is corroborated by their performance as roomtemperature lasers. Stimulated emission data for single-well quantum well heterostructures (QWH's) permit a direct measurement of the InGaAsP-lnP valence-band discontinuity (llEv). As the width of a single quantum well grows small, photogenerated electrons are poorly. collected, while the heavier-mass holes are efficiently collected. Recombination between "hot" electrons and bound holes produces radiation that is depressed from the InP bandgap energy by ~Ev' which is observed in the photoluminescence of single-well QWH's. The photoluminescence method is potentially the most direct and accurate measurement of heterojunction band discontinuities.U of I OnlyThesi

  • Liquid Phase Epitaxial Growth and Heterointerface Characteristics of Long-Wavelength Indium - Gallium Arsenide - Phosphide Heterostructures (Lasers, Semiconductors)
    2026
    Co-Authors: Brunemeier, Paul Edward
    Abstract:

    185 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1985.Data are presented that demonstrate that the InGaAsP quaternary grown by constant temperature liquid phase epitaxy on InP substrate can, under certain growth conditions, exhibit considerably narrower diffraction profile half-widths than previously reported. The double crystal x-ray diffraction half-width is a relatively new assay of crystalline alloy compositional homogeneity, and the 13 arc sec value presented here for InGaAsP may represent a lower limit for the homogeneity of this material system, as a result of alloy effects.Bandgap and lattice constant data are given that characterize the transient composition that occurs at the onset of liquid phase epitaxial growth of InGaAsP on InP substrates. This compositional inhomogeneity, a region of significantly different bandgap and lattice constant than that of the remainder of the layer, is a result of the extreme non-equilibrium conditions that exist in the first milliseconds of growth. The data presented here indicate a shift in mismatch and bandgap of (LESSTHEQ) 16 x 10('-4) and (LESSTHEQ) 20 meV, respectively, as a result of the transient composition. These results permit a calculation of the changes in the individual solidus atomic species, which illuminate some aspects of incorporation kinetic effects.Transmission electron microscopy (TEM) data are presented that characterize the interfacial "damage" that arises during the liquid phase epitaxial growth of an arsenic-poor InGaAsP quatenary on a previously grown arsenic-rich layer. This "damage" takes the form of a ragged heterointerface with extensive dislocations and is observed for some of the heterostructures examined. Other heterostructures are demonstrated that yield high-quality interfaces in TEM, which is corroborated by their performance as room-temperature lasers.Stimulated emission data for single-well quantum well heterostructures (QWH's) permit a direct measurement of the InGaAsP-InP valence-band discontinuity ((DELTA)E(,v)). As the width of a single quantum well grows small, photogenerated electrons are poorly collected, while the heavier-mass holes are efficiently collected. Recombination between "hot" electrons and bound holes produces radiation that is depressed from the InP bandgap energy by (DELTA)E(,v), which is observed in the photoluminescence of single-well QWH's. The photoluminescence method is potentially the most direct and accurate measurement of heterojunction band discontinuities.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD