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Full-Text Articles in Engineering

Development Of Battery-Grade Silicon Through Magnesiothermic Reduction Of Halloysite-Derived Silica, Nathan Clarke Dec 2023

Development Of Battery-Grade Silicon Through Magnesiothermic Reduction Of Halloysite-Derived Silica, Nathan Clarke

Theses and Dissertations

The production of halloysite-derived silicon (HDS) is investigated as a potential anode material in lithium-ion batteries (LIBs). Other researchers have found HDS to be electrochemically active in small test cells. To test larger electrochemical cells, the production process needs to be scaled up and optimized. HDS is produced through magnesiothermic reduction of acid-etched halloysite. The reduction process is very exothermic and requires special consideration while being scaled up. A reactor and pressure release system were designed and fabricated to perform the reduction process in a safe manner. Various steps of the process were tested to determine their influence on the …


Spectroscopic Studies On Silicon And Chalcopyrite Materials For Solar Energy Applications, Amandee Hua May 2023

Spectroscopic Studies On Silicon And Chalcopyrite Materials For Solar Energy Applications, Amandee Hua

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this dissertation, silicon-based materials for photovoltaics and chalcopyrite-based materials for photoelectrochemical water splitting are investigated using various spectroscopic and microscopic techniques. Although silicon dominates the photovoltaic market, further improvement can be made by using an alternative low temperature passivation approach. Currently, thermally grown SiO2 passivation is commonly used for silicon solar cells. However, this technique requires high processing temperatures (>800 °C), which increases the thermal budget, potentially decreases the bulk quality of Si, and can lead to difficulties in implementing in production lines. Here, a S-based passivation approach is studied that require lower processing temperatures of ~550 °C. …


Novel Photonic Structures And Materials, Samar Fawzy Oct 2022

Novel Photonic Structures And Materials, Samar Fawzy

Theses and Dissertations

Plasmonic materials provide the ability to confine light in metallic structures in the nanometre scale, enabling their use in a wide range of applications, including metamaterials, energy conversion, biomedical applications, and transformation optics. Conventional plasmonic materials such as Silver and Gold suffer from two problems: very large negative real permittivity (𝜀1), preventing their integration with low-permittivity dielectrics, and large losses associated with conduction electrons such as: electron-electron scattering, electron-phonon scattering or scattering by crystal defects. Therefore, the search for alternative structures and materials that overcome these obstacles is indeed an essential task. Metamaterials, three dimensional (3D) periodic subwavelength metallic/dielectric structures, …


Photon Attenuation Layer Silicon-Based X-Ray Detector: Quantum Efficiency Investigation And Algorithmic Processing Of Individual Detection Events, Kevin Larkin Jun 2022

Photon Attenuation Layer Silicon-Based X-Ray Detector: Quantum Efficiency Investigation And Algorithmic Processing Of Individual Detection Events, Kevin Larkin

ENGS 88 Honors Thesis (AB Students)

State-of-the-art X-ray detectors either use silicon direct detection—which is inefficient, as silicon is mostly transparent to high-energy X-rays—or rely on expensive scintillators to first down-convert X-ray photons to lower energies. Dr. Eldred Lee of Dartmouth College recently completed doctoral research that suggested the promise of a novel alternative: silicon-based X-ray detectors that utilize photon attenuation layers rather than scintillators. While Dr. Lee’s work is certainly rigorous and meritorious, background noise controls were rendered less effective by circumstances. The work presented in this thesis succeeded in implementing much better background noise controls for a series of new tests to compare the …


Characteristic Of The Dynamics Of Disorder In Crystalline And Amorphous Materials, Amir Behbahanian Dec 2021

Characteristic Of The Dynamics Of Disorder In Crystalline And Amorphous Materials, Amir Behbahanian

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This work provides the evidence to apply simulation methods that are applicable to systems with structural randomness to simulate crystalline materials at high temperatures. My work not only open the avenue to expand the simulation capability of materials but also provides insight to the physics of vibrations of atoms under different temperature and for different types of materials. I have also evaluated the reliability of Molecular Dynamics simulations at the frequency level and found that theses types of simulations, despite the previous belief, are reliable at low temperatures but up to a measurable frequency. In addition, the result of my …


Magnesiothermic Combustion Synthesis Of Nanocrystalline Silicon And Oxidation Kinetics Of Magnesium Particles, Sergio Cordova Aug 2021

Magnesiothermic Combustion Synthesis Of Nanocrystalline Silicon And Oxidation Kinetics Of Magnesium Particles, Sergio Cordova

Open Access Theses & Dissertations

Magnesium (Mg) is a well-known reduction agent in metallurgy (more specifically, in metallothermy). Recently, magnesiothermic reduction of oxides has been used in self-propagating high-temperature synThesis (SHS) of advanced materials such as ultrahigh-temperature ceramics (UHTC). The magnesiothermic SHS has also been used for the conversion of silica (SiO2) to silicon-based materials for thermoelectric applications. However, since oxidation of Mg releases a lot of heat, the direct use of it as the reduction agent leads to excessively high temperatures and undesirable sintering of the products. We have proposed to use magnesium silicide (Mg2Si) instead of Mg in the SHS of nanostructured silicon. …


Statistical And Variational Modeling And Analysis Of Passive Integrated Photonic Devices, Norbert Dinyi Agbodo May 2021

Statistical And Variational Modeling And Analysis Of Passive Integrated Photonic Devices, Norbert Dinyi Agbodo

Legacy Theses & Dissertations (2009 - 2024)

The success of Si as a platform for photonic devices and the associated availabilityof wafer-scale, ultra-high resolution lithography for Si CMOS has helped lead to the rapid advance of Si-based integrated photonics manufacturing over the past decade. This evolution is nearing the point of integration of Si-based photonics together with Si-CMOS for compact, high speed, high bandwidth, and cost-effective devices. However, due to the sensitive nature of passive and active photonic devices, variations inherent in wafer-based fabrication processes can lead to unacceptable levels of performance variation both within a give die and across a given wafer. Fully understanding the role …


Mechanical Analysis Of A Heterogeneously Integrated Silicon Photonic Interposer, Erica Charlene Graham May 2021

Mechanical Analysis Of A Heterogeneously Integrated Silicon Photonic Interposer, Erica Charlene Graham

Legacy Theses & Dissertations (2009 - 2024)

Overcoming the bandwidth bottleneck in conventional interconnects necessitates transitioning to alternative scaling paradigms. Silicon (Si) photonics is considered a disruptive technology, capable of meeting the growing demands for higher bandwidth, low latency, and power efficiency. By leveraging the intrinsic properties of optical signals and manufacturing compatibility of Si, the co-integration of Si photonics and complementary-metal-oxide-semiconductor (CMOS) circuitry leading to terabit data speeds for next generation data communication can be realized. Heterogeneously integrating Si photonic functionality with well-established CMOS technology in an Si photonic interposer architecture simultaneously provides independent optimization as well as close integration of both technologies in one platform. …


Optimization Of Cathode/Anode Electrode Materials For High Performance Lithium-Ion Batteries, Mingwei Shang Mar 2021

Optimization Of Cathode/Anode Electrode Materials For High Performance Lithium-Ion Batteries, Mingwei Shang

Theses and Dissertations

Lithium-ion batteries (LIBs) have been widely used in various devices such as portable devices, communication systems, and electric vehicles (EVs). In this dissertation, towards building LIBs with enhanced energy density and improved performance, Ni-rich cathode and Si-based anode are selected as the electrodes. The performance of LIBs is improved through optimization on both cathode and anode material. Ni-rich layered transition metal oxide with dual gradient on both primary and secondary particles was successfully designed and synthesized through introducing Ni-based metal-organic framework (Ni-MOF) to the coprecipitation of the precursor. During the calcination process, the presence of organic components of Ni-MOFs promotes …


Mechanical Strength Of Germanium Doped Low Oxygen Concentration Czochralski Silicon And The Effect Of Oxygen On Nitrogen Dissociation In Silicon, Junnan Wu Jan 2021

Mechanical Strength Of Germanium Doped Low Oxygen Concentration Czochralski Silicon And The Effect Of Oxygen On Nitrogen Dissociation In Silicon, Junnan Wu

McKelvey School of Engineering Theses & Dissertations

During the Czochralski growth of silicon, it is inevitable for oxygen to be incorporated into the silicon crystal from the quartz crucible. Interstitial oxygen improves the mechanical strength of silicon by pinning and locking dislocations, but also generates thermal donors during device processes, shifting the electrical resistivity. For silicon wafers used in radio frequency (RF) applications, it is important to ensure the high resistivity of the substrates for good RF characteristics. Therefore, the oxygen level in these high resistivity silicon wafers is kept very low (< 2.5 × 1017 atoms/cm3) by carefully controlling the Czochralski growth conditions, in order to reduce the thermal donor concentration to an acceptable level. Silicon on insulator (SOI) substrates made from high resistivity wafers have been widely used for RF applications. SOI manufacturing includes multiple high temperature thermal cycles (1000 – 1100 °C), during which the high resistivity wafers are prone to slip and warpage. Therefore, it is technologically important to recover some of the lost mechanical strength due to the lack of oxygen by introducing electrically inactive impurities to suppress the dislocation generation and mobility in silicon. Germanium (Ge) as an isovalent impurity is 4% larger in size and forms a solid solution with silicon in the entire concentration range. Previous works have shown Ge doping at high concentrations above 6 × 1019 atoms/cm3 increased mechanical strength of silicon with high oxygen concentration (~ 1 × 1018 atoms/cm3). In this work, we explore the effect of Ge doping (7 - 9 × 1019 atoms/cm3) on the mechanical strength of low oxygen concentration (< 2 × 1017 atoms/cm3) silicon, where the oxygen associated dislocation locking and pinning are very low. A mechanical bending test was used to study the average dislocation migration velocity and the critical shear stress of dislocations motion at 600 – 750 °C for Ge doped, nitrogen doped, and undoped low oxygen samples, as well as nitrogen doped float-zone and un-doped high oxygen concentration samples. Next, we fabricated SOI substrates using these high resistivity wafers and compared their slip generation rates and the slip-free epitaxial grow temperature windows after the high temperature thermal cycles (> 1000 °C). Our results indicate at lower temperature Ge doesn’t affect the dislocation mobility …


Numerical Calculation Of The Charge State And Electrostatic Potential Of A Binary Nanocluster Structure With Si2zns Cells In A Cubic Lattice Of Crystalline Silicon With A Diamond Structure, N.F. Zikrillaev, F.Q. Shakarov, M. K. Khaqqulov Sep 2020

Numerical Calculation Of The Charge State And Electrostatic Potential Of A Binary Nanocluster Structure With Si2zns Cells In A Cubic Lattice Of Crystalline Silicon With A Diamond Structure, N.F. Zikrillaev, F.Q. Shakarov, M. K. Khaqqulov

Technical science and innovation

Numerical calculation of electronic and atomic structures of complex systems of crystalline and transitional nano- and micro-sizes by using quantum physical methods will make it possible to forecast new properties of crystalline silicon with various concentrations of clusters of impurity atoms, structural arrangement at lattice sites and types of clusters. The quantum-chemical method was used to calculate the required characteristics of the cell, i.e. the charge state and electrostatic potential for the base matrix of Si (silicon) and silicon with an impurity cluster consisting of 3 tetrahedral cells type- Si2ZnS in the base lattice of Si. Calculation of …


Conductivity Reversal In Silicon Doped With S And Zn, Abdulaziz Shavkatovich Mavlyanov, Nurullo Zikrillayev, Maruf Khaqqulov, Erkin Khaltursunov, Farhod Shakarov Sep 2020

Conductivity Reversal In Silicon Doped With S And Zn, Abdulaziz Shavkatovich Mavlyanov, Nurullo Zikrillayev, Maruf Khaqqulov, Erkin Khaltursunov, Farhod Shakarov

Acta of Turin Polytechnic University in Tashkent

Based on experimental results of investigation of type of conductivity of silicon samples doped with sulfur at Т=1250°С, and thereafter with zinc at T=1200°С, the authors put forward the hypothesis about self-assembly of “binary” elementary cells where atoms of elements of group II (Zn) and IV (S) allegedly form ZnS-type compounds in Si. The thermodynamic conditions required for buildup of such elementary cells and assembly of various associations in the basic lattice of silicon including self-assembly of ZnS clusters were theoretically determined and experimentally justified.


Fabrication Of Silicon Microneedles For Dermal Interstitial Fluid Extraction In Human Subjects, Caleb A. Berry Aug 2020

Fabrication Of Silicon Microneedles For Dermal Interstitial Fluid Extraction In Human Subjects, Caleb A. Berry

Electronic Theses and Dissertations

The goal of this project is to design and develop a fabrication process for silicon microneedle arrays to extract dermal interstitial fluid (ISF) from human skin. ISF is a cell- free, living tissue medium that is known to contain many of the same, clinical biomarkers of general health, stress response and immune status as in blood. However, a significant barrier to adoption of ISF as a diagnostic matrix is the lack of a rapid, minimally invasive method of access and collection for analysis. Microfabricated chips containing arrays of microneedles that can rapidly and painlessly access and collect dermal ISF for …


In Vivo Silicon Lance Array Transfection Of Plant Cells, Taylor Andrew Brown Apr 2020

In Vivo Silicon Lance Array Transfection Of Plant Cells, Taylor Andrew Brown

Theses and Dissertations

Arrays of silicon lances were made using photolithographic and STS DRIE Bosch techniques. Arrays consist of a 10 mm square grid pattern of lances measuring 100 m tall and having a 3 mm diameter, each lance being spaced 30 mm apart. The tips of lances are pointed, allowing easier penetration through plant cell walls. A nanoinjector device was also made to accept the silicon lance arrays and perform nanoinjections. A nanoinjection consisted of 2 silicon lance arrays, with lances oriented towards each other, being moved into and out of a plant cotyledon placed between them. Prior to the nanoinjection, polar …


Optimal Technological Modes Of Ion Implantation And Following Annealing For Forming Thin Nanosized Films Of Silicides, A. S. Rysbaev, S. U. Irgashev, A. S. Kasimov, D. Sh. Juraeva, J. B. Khujaniyazov, M. I. Khudoyberdieva Mar 2020

Optimal Technological Modes Of Ion Implantation And Following Annealing For Forming Thin Nanosized Films Of Silicides, A. S. Rysbaev, S. U. Irgashev, A. S. Kasimov, D. Sh. Juraeva, J. B. Khujaniyazov, M. I. Khudoyberdieva

Eurasian Journal of Physics and Functional Materials

The formation of nanosized films of silicides on the surface of Si (111) and Si (100) was studied by the method of low-energy ion implantation. The optimal technological modes of ion implantation and subsequent annealing for the formation of thin nanoscale films of silicides were determined. It is shown that the appearance of new surface superstructures is additional confirmation of the formation of thin silicide films with a single crystal structure.


Preparation And Characterisation Of Metallorganic Precursors Derived Iron Oxides On Porous Silicon Layers, Sivakumar Balakrishnan, Yurii K. Gun'ko, Gerhard F. Swiegers, Tatiana S. Perova Jan 2020

Preparation And Characterisation Of Metallorganic Precursors Derived Iron Oxides On Porous Silicon Layers, Sivakumar Balakrishnan, Yurii K. Gun'ko, Gerhard F. Swiegers, Tatiana S. Perova

Australian Institute for Innovative Materials - Papers

Porous silicon has generated interest in scientific community after its photoluminescence discovery and thereafter, research was focused on to the chemical functionalization of silicon and subsequent anchoring of nanoparticles onto silicon surface. In the present work, the porous silicon has been effectively modified with magnetic nanoparticles which were prepared through metallorganic approach. The as-fabricated magnetic-porous silicon composites were characterised using FTIR and Raman spectroscopies, Scanning Electron Microscopy (SEM) as well as magnetic measurements.


Understanding And Mitigating The Electrochemical-Mechanical Degradation Of High Capacity Battery Electrodes, Dingying Dang Jan 2020

Understanding And Mitigating The Electrochemical-Mechanical Degradation Of High Capacity Battery Electrodes, Dingying Dang

Theses and Dissertations--Chemical and Materials Engineering

Lithium-ion batteries (LIBs) with high energy density and cycling stability play a critical role in developing electric vehicle (EV) and grid energy storage techniques. The electrochemical performance of LIBs can be improved by using high capacity positive (e.g., LiNi1/3Mn1/3Co1/3O2, i.e., NMC111) and negative (e.g., silicon) electrodes; both, however, experience severe electrochemical-mechanical degradation caused by the lithiation/delithiation induced volume changes. Understanding mechanical degradation mechanisms and their relationships with the capacity fading of electrodes is important for improving the cycling stability of electrodes as well as optimizing the design of electrodes with high capacity …


Change Of Electrophysical Properties Of The Si(111) And Si(100) Surface In The Process Of Ion Implantation And Next Annealing, A. S. Rysbaev, I. R. Bekpulatov, B. D. Igamov, Sh. X. Juraev Sep 2019

Change Of Electrophysical Properties Of The Si(111) And Si(100) Surface In The Process Of Ion Implantation And Next Annealing, A. S. Rysbaev, I. R. Bekpulatov, B. D. Igamov, Sh. X. Juraev

Eurasian Journal of Physics and Functional Materials

The change in the electrical properties of the Si(111) and Si(100) surfaces during ion implantation and subsequent annealing was studied. The possibilities of controlling of the electrophysical properties of the Si(111) and Si(100) surface layers by the implantation of ions of alkaline and alkaline-earth elements are analyzed. Some electrophysical properties of semiconductors containing p- and n-structures and the possibilities of their application in electronics are discussed.


Obtaining Homogeneous Silicon In The Process Of Alumothermic Reduction Of Silicon Dioxide, G. N. Chumikov, V. V. Klimenov, N. S. Tokmoldin, S. Zh. Tokmoldin Jun 2019

Obtaining Homogeneous Silicon In The Process Of Alumothermic Reduction Of Silicon Dioxide, G. N. Chumikov, V. V. Klimenov, N. S. Tokmoldin, S. Zh. Tokmoldin

Eurasian Journal of Physics and Functional Materials

The influence of charge components on emergence of a homogeneous phase of silicon in the process of silicon dioxide reduction by aluminium has been studied. Optimal process parameters affecting the quality of the end product have been identified. These include the ratio of components of the synthetic charge (CaO, SiO2 , CaF2 ), the optimal amount of SiO2 , the optimal amount of a reducing agent (Al) and the optimal Si/slag ratio. The homogeneous phase of silicon is easily separated from the slag, which contributes to the reduction of waste silicon during further technological operations.


Influence Of Heat Treatment On The Behaviorof Deep Levels In Silicon Doped By Tungsten, Shokhrukh Kh. Daliev, Abdugofur T. Mamadalimov, Sayfullo S. Nasriddinov, Anifa D. Paluanova Jun 2019

Influence Of Heat Treatment On The Behaviorof Deep Levels In Silicon Doped By Tungsten, Shokhrukh Kh. Daliev, Abdugofur T. Mamadalimov, Sayfullo S. Nasriddinov, Anifa D. Paluanova

Euroasian Journal of Semiconductors Science and Engineering

By means of Deep Level Transient Spectroscopy the kinetics of the annealing of the levels of tungsten in silicon during heat treatment in the temperature range 150÷4000С was studied. It was found a non-monotonic change in the concentration of deep levels Ec-0.30 eV and Ec-0.39 eV under isothermal annealing: the concentrations of both levels at short times increase, then the concentration level of Ec-0.30 eV sharply decreases, and the reduction of the concentration of deep level Ec-0.39 eV is much slower.


Infrared Spectroscopy Of Silicon Doped By Stannum And Manganese, Sharifa B. Utamuradova, Ravshanbek M. Ergashev, Khusniddin J. Matchanov Jun 2019

Infrared Spectroscopy Of Silicon Doped By Stannum And Manganese, Sharifa B. Utamuradova, Ravshanbek M. Ergashev, Khusniddin J. Matchanov

Euroasian Journal of Semiconductors Science and Engineering

The processes of defect formation in silicon doped by tin and manganese and their interaction with uncontrolled impurities were studied by infrared spectroscopy.It was found that the presence of impurities of transition and isovalent elements leads to a technological decrease in the concentration of process impurities – oxygen and carbon. It was found that the introduction of manganese in Si leads to a strong decrease in the concentration of interstitial optically active oxygen Noopt: in rapidly cooled samples Si there is a decrease of Noopt by 50% compared to the original Si.


Influence Of Impurities Of Refractory Elements On The Inefficiency Of Charge Transfer In Charged Communication Devices, Abdugafur T. Mamadalimov, Shakhrukh Kh. Daliev Jun 2019

Influence Of Impurities Of Refractory Elements On The Inefficiency Of Charge Transfer In Charged Communication Devices, Abdugafur T. Mamadalimov, Shakhrukh Kh. Daliev

Euroasian Journal of Semiconductors Science and Engineering

The influence of impurities of refractory elements on the inefficiency of charge transfer in charge-coupled devices is investigated. Found that the magnitude of the inefficiency of transfer  directly proportional to the density of surface States and the density of surface States in the CCD registers, with the resulting n losses n ≤ 0.1 depends on the type specially introduced impurities. It is shown that in CCD structures doped with impurities Ti, Zr and Hf relative to the control structures, the charge loss is greater, and in doped with impurities W and Mo, the charge loss is less.


Influence Of Rhodium And Iridium Impurity Atoms On The Capacitive Characteristics Of Si-Siо2 Structures, Khojakbar S. Daliev, Shakhriyor Kh. Yulchiev, Xotamjon J. Mansurov Jun 2019

Influence Of Rhodium And Iridium Impurity Atoms On The Capacitive Characteristics Of Si-Siо2 Structures, Khojakbar S. Daliev, Shakhriyor Kh. Yulchiev, Xotamjon J. Mansurov

Euroasian Journal of Semiconductors Science and Engineering

It was found that the doping of the semiconductor substrate with Rh and Ir atoms leads to the increase in the density of surface states at the Si – SiO2 interface. It is determined that the surface states, due to the presence of an impurity Rh and Ir are effective generation centers.


Influence Of Heat Treatment On The Behavior Of Deep Levels In Silicon Doped By Tungsten, Shokhrukh Kh. Daliev, Abdugofur T. Mamadalimov, Sayfullo S. Nasriddinov, Anifa D. Paluanova Jun 2019

Influence Of Heat Treatment On The Behavior Of Deep Levels In Silicon Doped By Tungsten, Shokhrukh Kh. Daliev, Abdugofur T. Mamadalimov, Sayfullo S. Nasriddinov, Anifa D. Paluanova

Euroasian Journal of Semiconductors Science and Engineering

By means of Deep Level Transient Spectroscopy the kinetics of the annealing of the levels of tungsten in silicon during heat treatment in the temperature range 150÷4000С was studied. It was found a non-monotonic change in the concentration of deep levels Ec-0.30 eV and Ec-0.39 eV under isothermal annealing: the concentrations of both levels at short times increase, then the concentration level of Ec-0.30 eV sharply decreases, and the reduction of the concentration of deep level Ec-0.39 eV is much slower.


Infrared Spectroscopy Of Silicon Doped By Stannum And Manganese, Sharifa B. Utamuradova, Ravshanbek M. Ergashev, Khusniddin J. Matchanov Jun 2019

Infrared Spectroscopy Of Silicon Doped By Stannum And Manganese, Sharifa B. Utamuradova, Ravshanbek M. Ergashev, Khusniddin J. Matchanov

Euroasian Journal of Semiconductors Science and Engineering

The processes of defect formation in silicon doped by tin and manganese and their interaction with uncontrolled impurities were studied by infrared spectroscopy.It was found that the presence of impurities of transition and isovalent elements leads to a technological decrease in the concentration of process impurities – oxygen and carbon. It was found that the introduction of manganese in Si leads to a strong decrease in the concentration of interstitial optically active oxygen Noopt: in rapidly cooled samples Si there is a decrease of Noopt by 50% compared to the original Si.


Capacitive Spectroscopy Of Defects In Semiconductors, Doped By Atoms Of Gadolinium, Shoakhriyor B. Norkulov, Khodjakbar S. Daliev, Makhmud Sh. Dehkanov, Uktam K. Erugliev Jun 2019

Capacitive Spectroscopy Of Defects In Semiconductors, Doped By Atoms Of Gadolinium, Shoakhriyor B. Norkulov, Khodjakbar S. Daliev, Makhmud Sh. Dehkanov, Uktam K. Erugliev

Euroasian Journal of Semiconductors Science and Engineering

The processes of formation of defects in silicon, doped by gadolinium are investigated by the method of DLTS. It is shown that in diffusion the introduction of Gd in the Si leads to the formation of deep levels with ionization energies Ec–0.23 eV, Ec–0.35 eV, Ec–0.41 eV and Ec–0.54 eV and a capture cross section of electrons n: 410-17cm-2, 210-15 cm2, 1.110-16 cm2 and 1.510-15 cm2, respectively, and in samples p-Si found only one level with Ev+0.32 eV.


Investigation Of Optical Second Harmonic Generation From Si (100) With Process Tailored Surface & Embedded Ag Nanostructures For Advanced Si Nonlinear Nanophotonics, Gourav Bhowmik Jan 2019

Investigation Of Optical Second Harmonic Generation From Si (100) With Process Tailored Surface & Embedded Ag Nanostructures For Advanced Si Nonlinear Nanophotonics, Gourav Bhowmik

Legacy Theses & Dissertations (2009 - 2024)

The challenge of current microelectronic architecture in transmission bandwidth and power consumption can be potentially solved by using silicon photonics technologies that are compatible with modern CMOS fabrication. One of the critical active photonic devices for Si photonics is a Si based optical modulator. Most of the reported silicon modulators rely on the free carrier plasma dispersion effect. In those cases, a weak change of the refractive index obtained by carrier accumulation, injection or depletion is utilized in a Mach-Zehnder interferometer or a microring resonator to achieve intensity modulation, rendering them difficult for chip-level implementation due to a large footprint …


Design, Layout, And Testing Of Sige Apds Fabricated In A Bicmos Process, Dane Laurence Gentry Dec 2018

Design, Layout, And Testing Of Sige Apds Fabricated In A Bicmos Process, Dane Laurence Gentry

UNLV Theses, Dissertations, Professional Papers, and Capstones

This Thesis is concerned with the design, layout, and testing of avalanche photodiodes (APDs). APDs are a type of photodetector and, thus, convert light signals into electrical signals (current or voltage). APDs can be fabricated using silicon (Si). In this Thesis, however, three integrated circuit (IC) chips containing various silicon-germanium (SiGe) APDs with different sizes, structures, and geometries were designed, laid out, and fabricated using the Austriamicrosystems (AMS) 0.35μm SiGe BiCMOS (S35) process. This was done in order to compare SiGe APDs to Si only APDs and investigate the hypothesis that SiGe APDs are capable of detecting longer wavelengths than …


Novel Methods For The Crystallization Of Thin Film Silicon, Shane Mcmahon Dec 2018

Novel Methods For The Crystallization Of Thin Film Silicon, Shane Mcmahon

Legacy Theses & Dissertations (2009 - 2024)

Underpinning much of the technological innovation over the past few decades in the fields of sensors, lighting, displays, and energy conversion has been thin-film electronics. While many of the surfaces in our environment have curvature, silicon wafers do not. Flexible electronics attempt to overcome this fundamental limitation in form factor. Flexible thin-film transistors (TFTs) can be fabricated over large areas to provide switching and driving elements for displays and other devices. While printable organic semiconductors have made significant advances over the past few years, they cannot match the performance capability, electrical quality, temperature compatibility, or stability of silicon. For this …


Comparison Of Organic And Inorganic Solar Photovoltaic Systems, Khulan Orgil Dec 2018

Comparison Of Organic And Inorganic Solar Photovoltaic Systems, Khulan Orgil

Electrical Engineering

This senior project report addresses the consumer’s need for accurate and easily accessible information when making a solar panel purchasing decision. Thus, the project analyzes and compares the costs and benefits of organic and inorganic photovoltaic systems during their life cycle. The cost comparison includes analysis of the environmental and economic costs of materials, production, installation, and disposal. The benefit comparison includes analysis of the economic, environmental, and social benefits accrued during the system’s lifetime. With the project’s data, consumers can make more informed decisions to fit their specific needs.