Fabrication And Characterization Of Electrochemical Glucose Sensors, 2018 University of Arkansas, Fayetteville
Fabrication And Characterization Of Electrochemical Glucose Sensors, Mohammed Marie
Theses and Dissertations
Electrochemical sensors based on the nanostructure of the semiconductor materials are of tremendous interest to be utilized for glucose monitoring. The sensors, based on the nanostructure of the semiconductor materials, are the third generations of the glucose sensors that are fast, sensitive, and cost-effect for glucose monitoring.
Glucose sensors based on pure zinc oxide nanorods (NRs) grown on different substrates, such ITO, FTO, and Si/SiO2/Au, were investigated in this research. Silicon nanowire (NW)- based glucose sensors were also studied. First, an enzyme-based glucose sensor was fabricated out of glass/ITO/ZnO NRs/BSA/GOx/nafion membrane. The sensor ...
Growth And Characterization Of Silicon-Germanium-Tin Semiconductors For Future Nanophotonics Devices, 2018 University of Arkansas, Fayetteville
Growth And Characterization Of Silicon-Germanium-Tin Semiconductors For Future Nanophotonics Devices, Bader Saad Alharthi
Theses and Dissertations
The bright future of silicon (Si) photonics has attracted research interest worldwide. The ultimate goal of this growing field is to develop a group IV based Si foundries that integrate Si-photonics with the current complementary metal–oxide–semiconductor (CMOS) on a single chip for mid-infrared optoelectronics and high speed devices. Even though group IV was used in light detection, such as photoconductors, it is still cannot compete with III-V semiconductors for light generation. This is because most of the group IV elements, such as Si and germanium (Ge), are indirect bandgap materials. Nevertheless, Ge and Si attracted industry attention because ...
Controlled Nanomorphology Of Hybrid Organic/Inorganic Multi-Component Composites Through Cooperative Non-Covalent Interactions, Lingyao Meng
Shared Knowledge Conference
Hybrid organic–inorganic nanocomposite polymers, with inorganic nanoparticles embedded in organic matrix have emerged as a special category of multifunctional materials. With rational materials design, these hybrids can show the synergistic effect of the properties from both phases. Homogenous dispersion and orderly arrangement of the organic and inorganic components are key in their functionalities. By controlling the interface and corresponding interfacial interactions between the organic and inorganic entities, we have developed a logical approach to form stable and controlled hybrid nanofiber structures. We demonstrate the formation of hybrid polymer/quantum dots (or iron oxide nanoparticles) nanocomposites through non-covalent interactions (hydrogen ...
Nanoflower-Like Bi2moo6/Ag3po4 In Water Treatment, 2018 University of Nevada, Las Vegas
Nanoflower-Like Bi2moo6/Ag3po4 In Water Treatment, Xavier Morgan-Lange, Jaeyun Moon, Kaleab Ayalew
McNair Poster Presentations
No abstract provided.
Thienoisatin Oligomers As N-Type Molecular Semiconductors, 2018 Purdue University
Thienoisatin Oligomers As N-Type Molecular Semiconductors, Natalie M. Kadlubowski, Xuyi Luo, Jianguo Mei
The Summer Undergraduate Research Fellowship (SURF) Symposium
Organic field effect transistors (OFETs) offer many advantages compared to traditional inorganic transistors, such as flexibility and solution processability. In this study we design and synthesize two thienoisatin-based organic semiconducting small molecules, then investigate their electronic properties in n-type OFETs. To introduce n-type charge transport, electron-withdrawing dicarbonitrile moieties were installed on thienoisoindigo and bis-thienoisatin molecules, which led to a quinoidal conjugation on thienoisoindigo, while maintaining an aromatic conjugation on the bis-thienoisatin. Following the syntheses, the molecules were characterized to determine highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels via cyclic voltammetry, as well as any potential ...
Application Of Nano-Plasmonics For Sers Bio-Detection And Photocatalysis In The Same Platform, 2018 Missouri State University
Application Of Nano-Plasmonics For Sers Bio-Detection And Photocatalysis In The Same Platform, Muhammad R. Shattique
MSU Graduate Theses
Nano-biological systems interfacing nano-structured solid surfaces with biological compounds such as oligonucleotides or proteins are highly regarded as enabling materials for biosensing and biocatalysis applications. In particular, nanostructures of noble metals such as gold or silver, when exposed to light, exhibit a phenomenon known as surface plasmon resonance. When a proper metal nanostructure (plasmonic substrate) is exposed to light, very efficient absorption of incoming photons is possible, resulting in a buildup of localized high-energy regions, or “hot-spots”, where energetic carriers or “hot carriers” can be created. These hot-carriers can be used to catalyze desired chemical transformations in materials located nearby ...
Non-Hysteretic First-Order Phase Transition With Large Latent Heat And Giant Low-Field Magnetocaloric Effect, F. Guillou, Arjun K. Pathak, Durga Paudyal, Yaroslav Mudryk, F. Wilhelm, A. Rogalev, Vitalij K. Pecharsky
Materials Science and Engineering Publications
First-order magnetic transitions (FOMTs) with a large discontinuity in magnetization are highly sought in the development of advanced functional magnetic materials. Isosymmetric magnetoelastic FOMTs that do not perturb crystal symmetry are especially rare, and only a handful of material families, almost exclusively transition metal-based, are known to exhibit them. Yet, here we report a surprising isosymmetric FOMT in a rare-earth intermetallic, Eu2In. What makes this transition in Eu2In even more remarkable is that it is associated with a large latent heat and an exceptionally high magnetocaloric effect in low magnetic fields, but with tiny lattice discontinuities and negligible hysteresis. An ...
Enhanced Coupling Strength Gratings For Outcouplers In Optical Waveguides, 2018 Southern Methodist University
Enhanced Coupling Strength Gratings For Outcouplers In Optical Waveguides, Ruo-Hua He
Electrical Engineering Theses and Dissertations
Gratings used for silicon photonic waveguides were demonstrated with outcoupling efficiency greater than 60% in a short grating length of 13 µm at a wavelength of 1550 nm. Due to problems of generating light from silicon, light has to be generated by either growing III-V material, wafer bonding III-V material to silicon, or externally generated light has to be coupled into and out of silicon photonic waveguides. Gratings have been used in semiconductor lasers to obtain single frequency operation. Some applications such as telecommunications require a narrow and single spectral line. And such single frequency lasers are typically distributed Bragg ...
Modeling Recombination In Solar Cells, 2018 Macalester College
Modeling Recombination In Solar Cells, Paul Chery
Macalester Journal of Physics and Astronomy
Solar cells are a competitive alternative to nonrenewable energy sources such as fossil fuels. However, the efficiency of these devices is limited by photogenerated carrier recombination. We use a finite difference numerical model to study recombination phenomena in the absorber layer of solar cells including alternate recombination models and the effects of spatial distribution of recombination centers. We compare the effect of using the constant lifetime approximation for recombination to the full Shockley-Read-Hall expression in Silicon solar cells and find that the constant lifetime approximation holds for high defect densities but not for high photon flux densities. Finally, we simulate ...
Solar Cell Potential Induced Degradation Sensor, 2018 California Polytechnic State University, San Luis Obispo
Solar Cell Potential Induced Degradation Sensor, Luc Alexandre Tousignant
It is important to maintain Photovoltaic (PV) cells and protect them from damage mechanisms like Potential Induced Degradation (PID), which can contribute to shorter lifespans and lower efficiencies. Current leakage through cell encapsulation can cause charge migration in PV cells that reduces the maximum quantum efficiency, which is the cause of PID. An experiment was setup to determine the feasibility of a non-silicon sensor able to produce similar leakage behavior to traditional PV cells under recorded humidity conditions. Thin sheet metals were encapsulated in EVA, a common PV encapsulant polymer, and mounted in aluminum framing. Three sensors, along with a ...
In Situ Sem Solidification Study Of Ga And Egain: A Characterization Technique For Monitoring The Microstructural Evolution Of Liquid Metals, 2018 California Polytechnic State University, San Luis Obispo
In Situ Sem Solidification Study Of Ga And Egain: A Characterization Technique For Monitoring The Microstructural Evolution Of Liquid Metals, Jeremy Geovann Del Aguila
Scanning electron microscopy (SEM) video recording is used to characterize the solidification of small volumes of 99.999% pure gallium (Ga) and eutectic gallium-indium (eGaIn) under a high vacuum environment. Specimen are superheated to 55℃ using a hot plate, cast into spherical droplets, and cooled in situ by means of a Peltier cooling stage. Special attention is given to the preparation of the specimen prior to viewing because of gallium and its alloys’ nature to form an oxide layer when melted and air cooled. The oxide acts as a skin that inhibits the observation of microstructural features during solidification. Heated ...
Three Speed 3d Printed Magnetic Gear, 2018 Portland State University
Three Speed 3d Printed Magnetic Gear, Robert J. Rutherford
Undergraduate Research & Mentoring Program
Power transmission is traditionally achieved with a mechanical gear. Mechanical gears require maintenance, cause vibration, and have no overload protection. Magnetic gears offer an innovative solution to these drawbacks as they do not require regular maintenance, have no need for lubrication, create very little acoustic noise, have built in overload protection and as a result of these advantages, have a longer lifetime of operation. This research focused upon the design, assembly and demonstration of the magnetic gear concept. The research used a solid works design, 3D printed ABS plastic housing, and use of neodymium magnets and ferromagnetic iron segments.
A Comparative Analysis Of Integrated Optical Waveguide Isolators With Magneto-Optic Layers, 2018 Southern Methodist University
A Comparative Analysis Of Integrated Optical Waveguide Isolators With Magneto-Optic Layers, Reyhane Oztekin
Electrical Engineering Theses and Dissertations
The objective of this study is to theoretically devise an on-chip optical isolator which is monolithically integrated with a semiconductor waveguide layer yielding low loss. The optical properties of iron are modeled for the use of optical waveguide isolators by improving the Brendel-Bormann model. Our model for iron shows excellent fit with the optical data up to 30 electronvolts (eV). The semiconductor optical waveguide isolator with magneto-optic layers based on non-reciprocal loss shift is developed in this study. Fe, Co, and Ni metals as well as cerium-substituted yttrium iron garnet (Ce:YIG) have been used as magneto-optic layers. We have ...
Voltage-Controlled Deposition Of Nanoparticles For Next Generation Electronic Materials, 2018 Louisiana State University and Agricultural and Mechanical College
Voltage-Controlled Deposition Of Nanoparticles For Next Generation Electronic Materials, Subhodip Maulik
LSU Doctoral Dissertations
This work presents both a feasibility study and an investigation into the voltage-controlled spray deposition of different nanoparticles, namely, carbon nanotubes (CNTs), as well as molybdenum disulfide (MoS2) and tungsten disulfide (WS2) from the transition metal dichalcogenides (TMDCs) family of materials. The study considers five different types of substrates as per their potential application to next-generation device electronics. The substrates selected for this research were: 1) aluminum as a conducting substrate, 2) silicon as a semiconducting substrate, 3) glass, silicon dioxide (SiO2), and syndiotactic poly methyl methacrylate (syndiotactic PMMA) as insulating substrates.
Since the 1990’s, carbon ...
Glucose Level Estimation Based On Invasive Electrochemical, And Non-Invasive Optical Sensing Methods, 2018 University of Arkansas, Fayetteville
Glucose Level Estimation Based On Invasive Electrochemical, And Non-Invasive Optical Sensing Methods, Sanghamitra Mandal
Theses and Dissertations
The purpose of this research is to design and fabricate sensors for glucose detection using inexpensive approaches. My first research approach is the fabrication of an amperometric electrochemical glucose sensor, by exploiting the optical properties of semiconductors and structural properties of nanostructures, to enhance the sensor sensitivity and response time. Enzymatic electrochemical sensors are fabricated using two different mechanisms: (1) the low-temperature hydrothermal synthesis of zinc oxide nanorods, and (2) the rapid metal-assisted chemical etching of silicon (Si) to synthesize Si nanowires. The concept of gold nano-electrode ensembles is then employed to the sensors in order to boost the current ...
Thermoelectrics And Thermoelectric Devices, 2018 Linfield College
Thermoelectrics And Thermoelectric Devices, Benjamin T. Erck
The field of thermoelectrics has many applications, and more are found in everyday systems. From its current studies, it is apparent that improving the figure of merit zT (which defines a good thermoelectric material) is important in the effectiveness of power generation. Another important part of thermoelectrics is the duality of these devices. They can both move heat and generate power, depending on their role in the system. In this thesis research, a process was made to test these thermoelectric relationships for a few Peltier devices in order to understand their efficiencies and what systems they can be applied to.
Reactive Lamination Of Perovskite Solar Cells., 2018 University of Louisville
Reactive Lamination Of Perovskite Solar Cells., Lyndie Burns
Electronic Theses and Dissertations
Due to the growing demand for energy internationally and the environmental impact of other conventional energy technologies, solar power has been a growing area in the energy landscape. Perovskite research has increased substantially because of the high power conversion efficiencies, up to 22%, with many recent advances in the use of these organic-inorganic hybrid perovskites for photovoltaic cells. However, to bring perovskite solar cells into the industrial world, the overall cost of the manufacturing of the solar cell must be improved to compete with other well-developed photovoltaic technologies. Here is presented an alternative perovskite deposition method for methylammonium lead halide ...
Design, Fabrication, And Characterization Of All-Inorganic Quantum Dot Light Emitting Diodes, 2018 University of Arkansas, Fayetteville
Design, Fabrication, And Characterization Of All-Inorganic Quantum Dot Light Emitting Diodes, Ramesh Vasan
Theses and Dissertations
Quantum dot light emitting diodes are investigated as a replacement to the existing organic light emitting diodes that are commonly used for thin film lighting and display applications. In this, all-inorganic quantum dot light emitting diodes with inorganic quantum dot emissive layer and inorganic charge transport layers are designed, fabricated, and characterized. Inorganic materials are more environmentally stable and can handle higher current densities than organic materials. The device consists of CdSe/ZnS alloyed core/shell quantum dots as the emissive layer and metal oxide charge transport layer. The charge transport in these devices is found to occur through resonant ...
Investigation Of Nanomaterial Based Photovoltaic Panel Packaging Materials, 2018 University of Arkansas, Fayetteville
Investigation Of Nanomaterial Based Photovoltaic Panel Packaging Materials, Xingeng Yang
Theses and Dissertations
In this research, nanomaterial-based packaging materials for photovoltaic (PV) panels are investigated. A hydrophobic/anti-reflective surface coating which not only repels water from the top glass of a PV panel but at the same time reduces its light reflectance is investigated. COMSOL simulation results indicate that taller ellipsoid rod (aspect ratio = 5) reflects less light than shorter rod (aspect ratio = 0.5) in the desired spectrum for solar energy harvest from 400nm-700nm. The addition of a polymer layer on these ellipsoid rods broadens the light incident angle from 23° to 34°, from which light can be efficiently absorbed. Based on ...
Near Bandgap Two-Photon Excited Luminescence Of Inas Quantum Dots, 2018 University of Arkansas, Fayetteville
Near Bandgap Two-Photon Excited Luminescence Of Inas Quantum Dots, Xian Hu
Theses and Dissertations
Semiconductor quantum dots (QDs) confine carriers in three dimensions, resulting in atomic-like energy levels as well as size-dependent electrical and optical properties. Self-assembled III-V QD is one of the most studied semiconductor QDs thanks to their well-established fabrication techniques and versatile optical properties. This dissertation presents the photoluminescence (PL) study of the InAs/GaAs QDs with both above bandgap continuous-wave excitation (one-photon excitation) and below-bandgap pulse excitation (two-photon excitation). Samples of ensemble QDs, single QD (SQD), and QDs in a micro-cavity, all grown by molecular beam epitaxy, are used in this study. Morphology of these samples was examined using atomic ...