Materials Science and Engineering Commons^™

Sno2 Particles Embedded Into Carbon Coated Mesoporous SioX Rod As High Volumetric Capacity Anode For Lithium-Ion Batteries, Jia-Lin Guo, Ni-Ni Li, Peng Zheng

Journal of Electrochemistry

Due to the high capacity and moderate volume expansion of silicon protoxide SiO_x (160%) compared with that of Si (300%), reducing silicon dioxide SiO₂ into SiO_x while maintaining its special nano-morphology makes it attractive as an anode of Li-ion batteries. Herein, through a one-pot facile high-temperature annealing route, using SBA15 as the silicon source, and embedding tin dioxide SnO₂ particles into carbon coated SiO_x, the mesoporous SiO_x-SnO₂@C rod composite was prepared and tested as the anode material. The results revealed that the SnO₂ particles were distributed uniformly in the …

A Cnt Intercalated Co Porphyrin-Based Metal Organic Framework Catalyst For Oxygen Reduction Reaction, Pei-Pei He, Jin-Hua Shi, Xiao-Yu Li, Ming-Jie Liu, Zhou Fang, Jing He, Zhong-Jian Li, Xin-Sheng Peng, Qing-Gang He

Journal of Electrochemistry

The poor electronic conductivity of metal-organic framework (MOF) materials hinders their direct application in the field of electrocatalysis in fuel cells. Herein, we proposed a strategy of embedding carbon nanotubes (CNTs) during the growth process of MOF crystals, synthesizing a metalloporphyrin-based MOF catalyst TCPPCo-MOF-CNT with a unique CNT-intercalated MOF structure. Physical characterization revealed that the CNTs enhance the overall conductivity while retaining the original characteristics of the MOF and metalloporphyrin. Simultaneously, the insertion of CNTs generated adequate mesopores and created a hierarchical porous structure that enhances mass transfer efficiency. X-ray photoelectron spectroscopic analysis confirmed that the C atom in CNT …

New Insights Into Controlling The Functional Properties Of Tin Oxide-Based Materials, Alexandra Kuriganova, Nina Smirnova

Journal of Electrochemistry

Development of methodologies for fabrications of nanostructured materials that provide control over their microstructural features and compositions represents a fundamental step in the advancement of technologies for productions of materials with well-defined functional properties. Pulse electrolysis, a top-down electrochemical approach, has been demonstrated to be a viable method for producing nanostructured materials with a particular efficacy in the synthesis of tin oxides. This method allows for significant control over the composition and shape of the resulting tin oxides particles by modifying the anionic composition of the aqueous electrolyte, obviating the need for additional capping agents in the synthesis process and …

Nanostructured Graphitic Carbon Nitride For Photocatalytic And Electrochemical Applications, Muhammad Abdul Qadeer, Iqra Fareed, Asif Hussaine, Muhammad Asim Farid, Sadia Nazir, Faheem K. Butt, Ji-Jun Zou, Muhammad Tahir, Shang-Feng Du

Journal of Electrochemistry

Graphitic carbon nitride (g-C₃N₄) exhibits great mechanical as well as thermal characteristics, making it a valuable material for use in photoelectric conversion devices, an accelerator for synthesis of organic compounds, an electrolyte for fuel cell applications or power sources, and a hydrogen storage substance and a fluorescence detector. It is fabricated using different methods, and there is a variety of morphologies and nanostructures such as zero to three dimensions that have been designed for different purposes. There are many reports about g-C₃N₄ in recent years, but a comprehensive review which covers nanostructure dimensions …

Novel Approach For The Micro Cracks Detection Of Solar Wafers And Cells, Mohd Israil, Arvind Kumar Sharma, Ekta Gupta

Al-Bahir

This paper deals with the review of various existing technique for the microcracks detection in silicon solar cell and wafer. In addition to this, we proposed a novel approach for the machine learning technique for the inspection of the cracks those are existed in the solar cell and wafer and not able to detect by the naked eyes. There are many techniques have been developed by the various researchers around the world to inspect solar cells for defect. All the techniques discussed in this article having some features and some weakness too. This paper present here gives the two-fold solution …

Optimizing Material Selection And Operational Conditions For Xhv Systems: Lessons From Aisi 1020 And 316l Comparative Studies, Aiman H. Al-Allaq, Md Abdullah Mamun, Matt Poelker, Abdelmageed Elmustafa

Mechanical & Aerospace Engineering Faculty Publications

In this study, AISI 1020 low-carbon steel was investigated as a cost-effective alternative to SS316L stainless steel for reaching extreme high vacuum (XHV) conditions. After being baked at 400°C, a vacuum chamber made of low-carbon steel material exhibited an outgassing rate approximately 2000 times smaller than a similar chamber made of stainless steel. Its activation energy for hydrogen diffusion (27 kJ/mol) is less than half that of stainless steel (60.3 kJ/mol), indicating more efficient hydrogen removal during bakeout. MolFlow+ simulations supported the experimental data and demonstrated the importance of system geometry optimization and minimizing stainless steel content for achieving optimal …

A Comprehensive Review Of Piezoelectric Pvdf Polymer Fabrications And Characteristics, Nadia Ahbab, Sidra Naz, Tian-Bing Xu, Shihai Zhang

Mechanical & Aerospace Engineering Faculty Publications

Polyvinylidene fluoride (PVDF) polymer films, renowned for their exceptional piezoelectric, pyroelectric, and ferroelectric properties, offer a versatile platform for the development of cutting-edge micro-scale functional devices, enabling innovative applications ranging from energy harvesting and sensing to medical diagnostics and actuation. This paper presents an in-depth review of the material properties, fabrication methodologies, and characterization of PVDF films. Initially, a comprehensive description of the physical, mechanical, chemical, thermal, electrical, and electromechanical properties is provided. The unique combination of piezoelectric, pyroelectric, and ferroelectric properties, coupled with its excellent chemical resistance and mechanical strength, makes PVDF a highly valuable material for a wide …

Nanomaterial-Enabled Enhancements In Thylakoid-Based Biofuel Cells, Amit Sarode, Gymama Slaughter

Center for Bioelectronics Publications

Thylakoid-based photosynthetic biofuel cells (TBFCs) harness the inherent light-driven electron transfer pathways of photosynthesis to enable sustainable solar-to-electrical energy conversion. While TBFCs offer a unique route toward biohybrid energy systems, their practical deployment is hindered by sluggish electron transfer kinetics, unstable redox mediators, and inefficient interfacing between biological and electrode components. This review critically examines recent advances in TBFCs, with a focus on three key surface engineering strategies: (i) incorporation of nanostructured materials to enhance electrode conductivity and surface area; (ii) application of redox mediators to facilitate charge transfer between photosynthetic proteins and electrodes; and (iii) functional exploitation of individual …

Solid Loading Effects On The Assembly Of Alumina Particles In Aqueous Suspensions Due To The Dielectrophoretic Forces, Sivakumar Chithamallu, Rohan Kiran Parai, Dipankar Ghosh

Mechanical & Aerospace Engineering Faculty Publications

Current work in situ investigated the mechanisms of the interparticle interactions that evolve in dilute aqueous alumina suspensions subjected to alternating current (AC) electric field and the effects of solid loading of suspensions. The interactions were investigated for alumina suspension compositions in the 0.005‒0.04 vol.% solid loading range. Field‐induced interactions evolved via particle motion and dynamic assembly, chain formation parallel to the direction of the applied field and chain growth, chain cross‐linking, and chain thickening. The evolution time of each of those events was rapidly accelerated with solid loading. While chain cross‐linking was negligible in low solid loading suspensions, a …

Epitaxial Quantum Dot Scintillators With Monolithic Photodetector Integration: Physics, Fabrication And Characterization Of Materials And Devices, Allan Oreave Minns

Electronic Theses & Dissertations (2024 - present)

This dissertation discloses the physics, fabrication, and characterization of high-performance scintillator detectors based on epitaxial InAs quantum dots (QDs) in GaAs. The detector crystals grown include monolithically integrated In_0.35GaAs photodetectors with Al_0.92-0.6In_0.03-0.35Ga_0.05As metamorphic buffer layers (MBL). A device fabrication process was developed for the lithographic patterning, chemical etching, contact metallization and readout integration of materials grown by means of molecular beam epitaxy (MBE) on 3-inch GaAs (001) wafers. Low capacitance integration with readout electronics was achieved through wire bonds to custom printed circuit boards (PCBs) with commercial components.

The relationship between device …

Mxenes In Biosensing: Enhancing Sensitivity And Flexibility - A Review Of Properties, Applications, And Future Directions, Ali Mohammad Amani, Lobat Tayebi, Ehsan Vafa, Alireza Jahanbin, Milad Abbasi, Ahmed Vaez, Hesam Kamyab, Lalitha Gnanasekaran, Shreeshivadasan Chelliapan

Electrical & Computer Engineering Faculty Publications

MXenes are a novel type of nanostructured material that has received a lot of attention for their potential applications in bioanalysis owing to their unique features. These materials, made from transition metal nitrides, carbides, or carbonitrides, have a number of advantages, including high hydrophilicity, a large surface area, strong metallic conductivity, superior ion transport capabilities, biocompatibility, and low diffusion barriers. Their surfaces are easily manipulated, making them more adaptable for a variety of applications, including biosensing. The outstanding properties of MXenes have attracted researchers of different fields, including renewable energy, fuel cells, supercapacitors, electronics, and catalysis. In the context of …

Optimizing Superconducting Nb Film Cavities By Mitigating Medium-Field Q-Slope Through Annealing, B. Abdisatarov, G. Eremeev, H. E. Elsayed-Ali, D. Bafia, A. Murthy, Z. Sung, A. Netepenko, A. Romanenko, C. P.A. Carlos, G. J. Rosaz, S. Calatroni, S. Leith, A. Grassellino

Electrical & Computer Engineering Faculty Publications

Niobium films are of interest in applications in various superconducting devices, such as superconducting radiofrequency cavities for particle accelerators and superconducting qubits for quantum computing. In this study, we address the persistent medium-field Q-slope issue in Nb film cavities, which, despite their high-quality factor at low RF fields, exhibit a significant Q-slope at medium RF fields compared to bulk Nb cavities. Traditional heat treatments, effective in reducing surface resistance and mitigating the Q-slope in bulk Nb cavities, are challenging for Nb-coated copper cavities. To overcome this challenge, we employed DC bias high-power impulse magnetron sputtering to deposit …

The Impact Of Chromium Ion Implantation On Ald Lead Chalcogenide Thin Films, Haifeng Cong, Charlotte Poterie, Jean Francois Barbot, Helmut Baumgart

Electrical & Computer Engineering Faculty Publications

Inherently the synthesis of semiconducting materials by Atomic Layer Deposition ALD produces only intrinsic undoped films which require the introduction of small amounts of impurities for doping to change them into extrinsic semiconductors. Apart from various in-situ diffusion doping techniques like delta doping during the ALD process, post deposition doping by ion implantation affords the best control of dose and doping profile. The present study investigates the impact of 180 keV Cr⁺ ion implantation on the properties of semiconducting ALD lead chalcogenide thin films to improve their thermoelectric figure of merit. The implantation was accomplished with 180 keV Chromium …

Potential Of Lidar And Hyperspectral Sensing For Overcoming Challenges In Current Maritime Ballast Tank Corrosion Inspection, Sergio Pallas Enguita, Jiajun Jiang, Chung-Hao Chen, Samuel Kovacic, Richard Lebel

Electrical & Computer Engineering Faculty Publications

Corrosion in maritime ballast tanks is a major driver of maintenance costs and operational risks for maritime assets. Inspections are hampered by complex geometries, hazardous conditions, and the limitations of conventional methods, particularly visual assessment, which struggles with subjectivity, accessibility, and early detection, especially under coatings. This paper critically examines these challenges and explores the potential of Light Detection and Ranging (LiDAR) and Hyperspectral Imaging (HSI) to form the basis of improved inspection approaches. We discuss LiDAR’s utility for accurate 3D mapping and providing a spatial framework and HSI’s potential for objective material identification and surface characterization based on spectral …

Quantifying Trapped Magnetic Vortex Losses In Niobium Resonators At Mk Temperatures, D. Bafia, B. Abdisatarov, R. Pilipenko, Y. Lu, G. Eremeev, A. Romanenko, A. Grassellino

Electrical & Computer Engineering Faculty Publications

Trapped magnetic vortices in niobium introduce microwave losses that degrade the performance of superconducting resonators. While such losses have been extensively studied above 1 K, we report here their direct quantification in the millikelvin and low-photon regime relevant to quantum devices. Using a high-quality factor 3D niobium cavity cooled through its superconducting transition in controlled magnetic fields, we isolate vortex-induced losses and find the resistive component of the sensitivity to trapped flux S to be approximately 2 n Ω/mG at 10 mK and 6 GHz. The decay rate is initially dominated by two-level system (TLS) losses from the native niobium …

Rheology Of Alumina Suspensions Subjected To Alternating Current Electric Fields For Freeze-Casting, Sivakumar Chithamallu, Ruksana Baby, Jacob L. Jones, Dipankar Ghosh

Mechanical & Aerospace Engineering Faculty Publications

Alternating current (AC) electric field can extrinsically tune freeze‐cast microstructure, originating from field‐induced increase in viscosity of ceramic suspensions. However, the changes that occur in a ceramic suspension and rheological behavior, ultimately affecting freeze‐cast microstructure, are not well understood. Moreover, the effects of AC electrokinetic forces and temperature on viscosity need to be decoupled. The viscosity and temperature of ceramic suspensions subjected to AC field and direct heating were measured, revealing that the increase in viscosity is due to AC dielectrophoretic forces rather than field‐induced heating of suspension. The shear thinning behavior of suspensions characterized using a power‐law model reveals …

Distributed Sapphire Fiber Bragg Grating-Based Thermal Profiling Of Submerged Entry Nozzles, Farhan Mumtaz, Hanok W. Tekle, Bohong Zhang, Xiaodong Li, Sunday Abraham, Bryant Mathis, Jeffrey D. Smith, Ronald J. O'Malley, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This article focuses on the application of sapphire fiber Bragg gratings (FBGs) for instrumentation in submerged entry nozzles (SENs) within the steelmaking industry. The SEN is pivotal for transferring molten steel from a tundish to a mold, while preventing the infiltration of oxygen and nitrogen from the surrounding environment. Maintaining optimal flow conditions in the mold is crucial for ensuring casting process stability and maintaining high-quality steel. Sapphire FBG sensors have been instrumented in SENs to enable distributed thermal mapping for monitoring the health of the SEN. The optical sensor comprises three cascaded sapphire FBGs inscribed using femtosecond (FS) laser …

Discrimination Of Temperature And Strain By Characterizing Two Femtosecond Laser-Written Coincident Sapphire Fiber Bragg Gratings For Harsh Environment Applications, Farhan Mumtaz, Bohong Zhang, Koustav Dey, Jeffrey D. Smith, Ronald J. O'Malley, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

In this study, two co-incident sapphire fiber Bragg gratings (SFBGs) were successfully inscribed utilizing a femtosecond (fs) laser to achieve a high fringe contrast interferogram. These two SFBGs employ a unique configuration, one parallel to the center axis, called p-SFBG, and the other forming an angle from the center-axis, called a-SFBG, allowing for simultaneous strain and temperature measurements with low crosstalk. As a proof of concept, p-SFBG and a-SFBG using line-by-line method are characterized, which are shorter in length (i.e., 1.5 mm), producing reflectivity of ~3dB. This effort demonstrates the use of two coincident SFBGs forming an angle of 2.29° …

Advancing Temperature Monitoring Of The Bottom Anode In A Direct Current Electric Arc Furnace Operations With Distributed Optical Fiber Sensors., Ogbole Collins Inalegwu, Rony Kumer Saha, Yeshwanth Reddy Mekala, Farhan Mumtaz, Nicholas Dionise, Zane Voss, Jeffrey D. Smith, Ronald J. O'Malley, Rex E. Gerald, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

The bottom anode in the Direct Current Electric Arc Furnace (DC EAF) is critical for completing the electrical circuit necessary for sustaining the arc within the furnace. For pin-type bottom anodes, monitoring of the temperature of select pins instrumented with thermocouples is performed to track bottom wear in the EAF and inform the operator when the furnace should be removed from service. This work presents the results from a plant trial using distributed temperature monitoring of bottom anode pins in a 165-ton DC EAF over a two-month service period utilizing two optical fiber sensing techniques: fiber Bragg grating (FBG) and …

Surface Morphology And Moisture Adsorption/Desorption Characteristics Of Hybrid-Dielectric Moisture Sensors, Ronak Ali

Theses and Dissertations--Electrical and Computer Engineering

Relative humidity sensors are used for high-humidity measurement. Moisture sensors, or dew point sensors are used for low-humidity measurement (< 1 ppm_v). The dissertation contains two parts of studies. In the first part, the effect of surface morphology on the response speed of moisture sensors is studied. Moisture sensors using α-Al₂O₃ films as porous dielectric materials deposited by anodic spark deposition are studied. In this part of the study, a variety of small pores have been studied to investigate the response speed of moisture sensors. Three different surface morphologies have been studied using scanning electron microscopy. One …

Laser-Induced Graphene For Early Disease Detection: A Review, Sri Ramulu Torati, Gymama Slaughter

Center for Bioelectronics Publications

Electrochemical biosensors have been instrumental in early disease detection, facilitating effective monitoring and treatment. The emergence of graphene has significantly advanced sensor technology in various fields, including biomedicine, electronics, and energy. In this landscape, laser‐induced graphene (LIG) has emerged as a superior alternative to conventional graphene synthesis methods. Its straightforward fabrication process and compatibility with wearable devices boost its practicality and potential for real‐world applications. This review highlights the transformative potential of LIG in biosensing, showcasing its contributions to the development of next‐generation diagnostic tools for early disease detection. An overview of the LIG synthesis process and its applications in …

Preparation Of Mocvd-Grown Photocathodes Containing A Strained Gaas/Gaasp Superlattice, G. Blume, A. Masters, J. Grames, M. Stutzman, M. Grau, S. Marsillac

Physics Faculty Publications

In this work, we investigate heat cleaning options for high-polarization GaAs/GaAsP strained-superlattice (SSL) photocathodes with a distributed Bragg reflector (DBR) that were grown using metalorganic chemical vapor deposition (MOCVD). This was done using a microMott polarimeter at Jefferson Lab to optimize both quantum efficiency and polarization. The fabrication process for MOCVD-grown photocathodes does not allow for the inclusion of an arsenic cap, contrary to what is done when fabricating photocathodes using molecular-beam epitaxy (MBE). Without proper preparation, the performance of MOCVD-grown photocathodes can be limited due to surface contamination. Here, we varied both duration and temperature of the heat cleaning …

Dendrite-Free Strategies For Aqueous Zinc-Ion Batteries: Structure, Electrolyte, And Separator, Gang Wu, Wu-Hai Yang, Yang Yang, Hui-Jun Yang

Journal of Electrochemistry

Continued growth in energy demand and increased environmental pollution constitute major challenges that need to be addressed urgently. The development and utilization of renewable, sustainable, and clean energy sources, such as wind and solar, are crucial. However, the instability of these intermittent energy sources makes the need for energy storage systems increasingly urgent. Aqueous zinc-ion batteries (AZIBs) have received widespread attention due to their unique advantages, such as high energy density, cost-effectiveness, environmental friendliness, and safety. However, AZIBs face significant challenges, mainly the formation of zinc dendrites that seriously affect the stability and lifetime of the batteries, leading to battery …

Electrochemical-Method-Induced Strong Metal-Support Interaction In Pt-Cnt@Sno2 For Co-Tolerant Hydrogen Oxidation Reaction, Shen-Zhou Li, Zi-Jie Lin, Qi-An Chen, Zhao Cai, Qing Li

Journal of Electrochemistry

Inducing the classic strong metal-support interaction (SMSI) is an effective approach to enhance the performance of supported metal catalysts by encapsulating the metal nanoparticles (NPs) with supports. Conventional thermal reduction method for inducing SMSI processes is often accompanied by undesirable structural evolution of metal NPs. In this study, a mild electrochemical method has been developed as a new approach to induce SMSI, using the cable structured core@shell CNT@SnO₂ loaded Pt NPs as a proof of concept. The induced SnO_x encapsulation layer on the surface of Pt NPs can protect Pt NPs from the poisoned of CO impurity in …

Contributions To Journal Of Electrochemistry, The Flagship Journal Of Chinese Chemical Society Electrochemical Committee, Will Be Listed As A New Recommendation Policy For China Youth Awards Of Electrochemist, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

All-Solid-State Sodium-Ion Batteries: A Leading Contender In The Next-Generation Battery Race, Rui-Jie Zhu, Ze-Chen Li, Wei Zhang, Akira Nasu, Hiroaki Kobayashi, Masaki Matsui

Journal of Electrochemistry

All-solid-state lithium-ion batteries (LIBs) using ceramic electrolytes are considered the ideal form of rechargeable batteries due to their high energy density and safety. However, in the pursuit of all-solid-state LIBs, the issue of lithium resource availability is selectively overlooked. Considering that the amount of lithium required for all-solid-state LIBs is not sustainable with current lithium resources, another system that also offers the dual advantages of high energy density and safety— all-solid-state sodium-ion batteries (SIBs) —holds significant sustainable advantages and is likely to be the strong contender in the competition for developing next-generation high-energy-density batteries. This article briefly introduces the research …

Ge/Sige Quantum Wells: Material For The Post-Moore Era, Troy Alexander Hutchins-Delgado

Optical Science and Engineering ETDs

This dissertation demonstrates high-quality germanium quantum wells on a 200 mm silicon wafer platform, enabling novel device possibilities. Partnering with a commercial silicon-germanium epitaxy supplier, we obtained shallow, undoped germanium quantum wells with high-crystalline quality, confirmed through x-ray diffraction, secondary ion mass spectroscopy, high-resolution scanning transmission electron microscopy, and energy dispersive x-ray spectroscopy. Hall bar devices fabricated on single quantum wells revealed that surface preparation can tune transport properties while maintaining peak mobilities around 10⁵ cm²V⁻¹s⁻¹. Manganese-germanide spintronic contacts were integrated via solid-state reaction, with contact quality assessed through Schottky diodes, transfer length …

Ellipticity-Controlled Exceptional Points From Nanoscale Metasurfaces, Benjamin Goldberg

McKelvey School of Engineering Graduate Student Theses & Dissertations

Precise control over light polarization is critical for advancing technologies in telecommunica- tions, quantum computing, and image sensing. However, existing methods for manipulating polarization around exceptional points in non-Hermitian systems, have exclusively focused on circular polarization and work with reflected light. To address this limitation, we de- velop a novel metasurface platform with high-Q resonators that enables tunable control of polarization exceptional points across arbitrary ellipticity for transmitted light. Our design uses orthogonally polarized guided mode resonators in a two-layer silicon metasurface, where careful tuning of the dipolar guided mode resonances (DGMRs) and layer spacing allows us to control the …

Ohmic Contacts For Fabrication Of Sic Cmos Devices, Anthony Di Mauro

Graduate Theses and Dissertations

Today’s world of electronics is dominated by semiconductor devices which utilize silicon as their substrate material. Though, silicon is not ideal for semiconductor devices in high-voltage or high-temperature applications. Additionally, the efficiency of silicon devices becomes drastically reduced in nonideal operating conditions. Therefore, finding alternatives to silicon?based devices has been a topic for decades now. A few great candidates to replace silicon devices for said applications include Silicon Carbide (SiC), Gallium Nitride (GaN), and Aluminum Arsenide (AlAs). SiC has grown its reputation as the best candidate, when compared to other potential alternatives, due to its wide bandgap, high operating frequency, …

Investigation Of Conductive Die-Top Thermal Capacitors During Short Circuit Operation Of Silicon Carbide Devices, Youssef Abotaleb

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Silicon carbide (SiC) power devices have garnered significant attention in recent years due to their superior thermal and electrical properties compared to traditional silicon devices. However, SiC power devices suffer from severe reliability issues arising from their mechanical properties. This is because the Young's modulus of SiC is about three times larger than that of silicon, which correspondingly raises the mechanical stresses acting on the bonding structure, often leading to device failure under power shock events.

Traditional packaging materials and designs tend to constrain SiC performance, as hot-spot temperature resulting from a power shock is one of the key factors …