Semiconductor and Optical Materials Commons^™

Lafe0.925ti0.075o3 Perovskite Coated With Ethyl Cellulose: A High-Stability, Low-Hysteresis Platform For Advanced Humidity Sensing, Akhmad Futukhillah Fataba Alaih, Djoko Triyono, Rifqi Almusawi Rafsanjani

Makara Journal of Science

Humidity sensors are pivotal in numerous sectors, such as environmental monitoring, industrial automation, and health-care. This study presents the fabrication and detailed evaluation of an advanced humidity sensor using ethyl cellulose (EC)-coated LaFe_0.925Ti_0.075O₃ (LFTO) perovskite nanoparticles synthesized via the sol-gel method. The LFTO nanopar-ticles exhibited a mesoporous structure with an enhanced surface area, which significantly improved their moisture adsorption capabilities. The innovative application of EC coating addresses critical substrate adhesion issues, enhancing mechanical stability without compromising sensor sensitivity. Comprehensive performance evaluations revealed minimal hysteresis (

Temperature And Environmental Implications On Ti3c2cl2 Mxene Degradation Process, Yang Yang

McKelvey School of Engineering Graduate Student Theses & Dissertations

MXenes, a rapidly emerging class of two-dimensional transition metal carbides and nitrides, have attracted considerable attention owing to their exceptional electrical, mechanical, and chemical properties. However, the inherent thinness of their atomic structure and the reactivity of their functional groups render MXenes susceptible to environmental degradation, whereby the lattice integrity is compromised and desirable material functionalities are dimin- ished. In this work, ex situ electron microscopy characterisation is performed on Ti₃C₂Cl₂ MXene specimens subjected to controlled gas environments — nitrogen gas (N₂) and air — at annealing temperatures of 200°C and 600°C, with …

An Overview Of Biomass-Derived Graphene Oxide And Its Characteristics For Future Sustainable Applications, Afif Wardana, Ahmad Nabil Shahab, Donanta Dhaneswara, Nofrijon Sofyan

Journal of Materials Exploration and Findings

The production of graphene oxide (GO) from biomass presents considerable promise as a sustainable alternative substitute for traditional semiconductors. Biomass waste, abundant and often underutilized worldwide, is distinguished by its high carbon content and regenerative characteristics, rendering it an optimal resource for sustainable material production. By heating its biopolymers, lignocellulosic biomass can be used as a new material to make graphene, which forms three-dimensional turbostratic crystallites. These crystallites, composed of partially defective aromatic carbon sheets with graphite-like characteristics, make it easier to create GO with specialized functions for cutting-edge applications. Its capability underscores the revolutionary potential of biomass waste in …

Advanced Manufacturing Of Multifunctional Shape Memory Polymer Composites And Self-Healing Systems, John B. Konlan

LSU Doctoral Dissertations

The need for multifunctional light weight structures for engineering applications is on the rise. Multifunctional composites are desired because of their ability to combine multiple functionalities into one structure. The advantages of a high strength-to-weight ratio of multifunctional composites make them desirable and suitable for use in energy-efficient applications. Shape-memory polymers (SMPs) have attracted interest over the past several decades because of their multifunctional nature. They have found use in many applications such as aerospace, satellites, automobiles, textiles, and biomedical devices, where lightweight and multifunctionality are key. The self-healing nature of most SMPs makes them suitable for use in lightweight …

Effect Of Niobium Dopant On Zno Thin Films Prepared Via The Sol–Gel Spin Coating Method, Kevin Alvin Eswar, Nur Fairuz Rostan, Maryam Mohamad, Rabiatuladawiyah Md Akhir, Rosfayanti Rasmidi, Muliyadi Guliling, Najwa Ezira Azhar, Irmaizatussyehdany Buniyamin, Mohd Firdaus Malek, Mohamad Rusop Mahmood, Husairi Fadzilah Suhaimi, Saifollah Abdullah

Makara Journal of Science

Thin films of zinc oxide (ZnO) and niobium (Nb)-doped ZnO were deposited on a glass substrate using the sol–gel spin coating method. Diethanolamine, isopropyl alcohol, and zinc acetate served as the stabilizers, solvent, and starting ma-terial, respectively. Niobium pentachloride was employed as the dopant source. Energy-dispersive X-ray analysis con-firmed Nb incorporation. Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and ultravio-let–visible spectroscopy (UV–Vis) analyses characterized the morphology, structure, and optics of the films, respective-ly. Both films, comprising nanoparticles, were visible in FESEM. Nb doping reduced the particle size from 44.2 nm to 35.8 nm. The XRD peaks at 31.23°, …

Xps And Ipe Determination Of Band Offsets Of Germanium Based Materials, Justin Michael Rudie

Graduate Theses and Dissertations

Germanium tin and silicon germanium tin are group IV semiconductor alloys that have gained significant interest in recent years for their potential use in optoelectrical devices. While silicon and germanium are indirect bandgap materials on their own, alloying them with tin in sufficient quantities leads to a transition to direct bandgap alloys. Direct gap performance opens the door for efficient light emitting and detecting devices fabricated entirely on group IV materials that are compatible with the industry standard CMOS manufacturing techniques. Germanium tin and silicon germanium tin have bandgaps that respond to light in the mid to near infrared spectrum …

Design And Fabrication Of Nanostructured Electrodes For Complementary Electrochemical And Photoelectrochemical Water Splitting, Kholoud El Sayed Abousalem

Theses and Dissertations

Designing highly active, durable, and nonprecious electrodes for overall water splitting is of urgent scientific importance to realize sustainable hydrogen production. Accordingly, the need to search efficient energy production systems is of crucial necessity. In this thesis, two various systems for sustainable hydrogen production have been reported using electrochemical and photoelectrochemical pathways. In the first part of the thesis, electrochemical water splitting involving both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) has been established. To this end, an innovative approach is demonstrated to synthesize flower-like 3D homogenous trimetallic Mn, Ni, Co phosphide catalysts directly on nickel foam via …

Rapid Annealing Of Perovskite Solar Cell Thin Film Materials Through Intense Pulse Light., Amir Hossein Ghahremani

Electronic Theses and Dissertations

Perovskite solar cells (PSCs) have garnered a great attention due to their rapid efficiency improvement using cheap and solution processable materials that can be adapted for scalable high-speed automated manufacturing. Thin film perovskite photovoltaics (PVs) are typically fabricated in an inert environment, such as nitrogen glovebox, through a set of deposition and annealing steps, each playing a significant role on the power conversion efficiency (PCE), reproducibility, and stability of devices. However, atmospheric processing of PSCs would achieve lucrative commercialization. Therefore, it is necessary to utilize materials and methods that enable successful fabrication of efficient PSCs in the ambient environment. The …

Nature-Inspired Material Strategies Towards Functional Devices, Sayantan Pradhan

Theses and Dissertations

Naturally sourced, renewable biomaterials possess outstanding advantages for a multitude of biomedical applications owing to their biodegradability, biocompatibility, and excellent mechanical properties. Of interest in this dissertation are silk (protein) and chitin (polysaccharide) biopolymers for the fabrication of functional biodevices. One of the major challenges restricting these materials beyond their traditional usage as passive substrate materials is the ability to combine them with high-resolution fabrication techniques. Initial research work is directed towards the fabrication of micropatterned, flexible 2D substrates of silk fibroin and chitin using bench-top photolithographic techniques. Research is focused on imparting electrochemical properties to silk proteins using conducting …

Development Of Light Actuated Chemical Delivery Platform On A 2-D Array Of Micropore Structure, Hojjat Rostami Azmand, Hojjat Rostami Azmand

Dissertations and Theses

Localized chemical delivery plays an essential role in the fundamental information transfers within biological systems. Thus, the ability to mimic the natural chemical signal modulation would provide significant contributions to understand the functional signaling pathway of biological cells and develop new prosthetic devices for neurological disorders. In this paper, we demonstrate a light-controlled hydrogel platform that can be used for localized chemical delivery in a high spatial resolution. By utilizing the photothermal behavior of graphene-hydrogel composites confined within micron-sized fluidic channels, patterned light illumination creates the parallel and independent actuation of chemical release in a group of fluidic ports. The …

The Development Of All Solid-State Optical Cryo-Cooler, Junwei Meng

Optical Science and Engineering ETDs

This dissertation describes the development of an all solid-state optical cryo-cooler. Crystals of 10% wt. ytterbium-doped yttrium lithium fluoride (Yb³⁺:YLF) are used to cool an infrared HgCdTe sensor payload to an absolute temperature below 135 K, equivalent to delta T equal 138 K below ambient. This record level of cooling is accomplished with a single stage, in a completely vibration-free environment, with a corresponding cooling power of 190 mW. This milestone is made possible by the design and fabrication of an undoped YLF thermal link that efficiently shields the payload with a non-right angle kink from intense anti-Stokes …

Characterization Of Contact Resistance Properties Of Different Tlm Structure Designs, Nicole A. Karam Pannaci

Digital Repository: Showcase of Undergraduate Research Excellence

No abstract provided.

Investigation Of Nanomaterial Based Photovoltaic Panel Packaging Materials, Xingeng Yang

Graduate 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 …

Investigating The Classical And Non-Classical Mechanical Properties Of Gan Nanowires, Mohammad Reza Zamani Kouhpanji

Electrical and Computer Engineering ETDs

Study and prediction of classical and non-classical mechanical properties of GaN is crucial due to the potential application of GaN nanowires (NWs) in piezoelectric, probe-based nanometrology, and nanolithography areas. GaN is mainly grown on sapphire substrates whose lattice constant and thermal expansion coefficient are significantly different from GaN. These discrepancies cause mechanical defects and high residual stresses and strains in GaN, which reduce its quantum efficiency.

Specifically, for nanoscale applications, the mechanical properties of materials differ significantly compared to the bulk properties due to size-effects. Therefore, it is essential to investigate the mechanical properties of GaN NWs using the non-classical …

Fabrication And Study Of The Structure And Magnetism Of Rare-Earth Free Nanoclusters, Bhaskar Das

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

No abstract provided.

Study Of Nano-Bio Interfaces In Nano-Bio Conjugates: Nanoparticles Of Zinc Oxide (Zno) And Biomolecules Of Glucose, Cytosine, And Thymine, Bithi Paul

Graduate Theses/Dissertations

Nano conjugates, composites of inorganic nanomaterials and bio molecules such as DNA, RNA and proteins, establish a sequence of wide varieties of nano-bio boundaries. The formation of these boundaries strongly depends on bio physicochemical reaction of biomolecules coated on the surface of nanomaterials. I am investigating various nano-bio conjugates consisting of zinc oxide (ZnO) nanoparticles with simple biomolecules including glucose and the nitrogenous bases of DNA such as cytosine and thymine. All nano-bio conjugates were fabricated using a standard bio-chemical synthesis process. Structural, physical, bio-chemical interface properties of nano-bio composites were probed using X-ray diffraction (XRD), Raman spectroscopy, and photoluminescence …

Improving The Capacity, Durability And Stability Of Lithium-Ion Batteries By Interphase Engineering, Qinglin Zhang

Theses and Dissertations--Chemical and Materials Engineering

This dissertation is focus on the study of solid-electrolyte interphases (SEIs) on advanced lithium ion battery (LIB) anodes. The purposes of this dissertation are to a) develop a methodology to study the properties of SEIs; and b) provide guidelines for designing engineered SEIs. The general knowledge gained through this research will be beneficial for the entire battery research community.

Beyond Conventional C-Plane Gan-Based Light Emitting Diodes: A Systematic Exploration Of Leds On Semi-Polar Orientations, Morteza Monavarian

Theses and Dissertations

Despite enormous efforts and investments, the efficiency of InGaN-based green and yellow-green light emitters remains relatively low, and that limits progress in developing full color display, laser diodes, and bright light sources for general lighting. The low efficiency of light emitting devices in the green-to-yellow spectral range, also known as the “Green Gap”, is considered a global concern in the LED industry. The polar c-plane orientation of GaN, which is the mainstay in the LED industry, suffers from polarization-induced separation of electrons and hole wavefunctions (also known as the “quantum confined Stark effect”) and low indium incorporation efficiency that …

Characterization Of And Controlling Morphology Of Ultra-Thin Nanocomposites, Guy C. Laine

Theses and Dissertations--Chemical and Materials Engineering

Ultrathin film nanocomposites are becoming increasingly important for specialized performance of commercial coatings. Critical challenges for ultrathin film nanocomposites include their synthesis and characterization as well as their performance properties, including surface roughness, optical properties (haze, refractive index as examples), and mechanical properties. The objective of this work is to control the surface roughness of ultrathin film nanocomposites by changing the average particle size and the particle volume fraction (loading) of monomodal particle size distributions. This work evaluated one-layer and two-layer films for their surface properties. Monodispersed colloidal silica nanoparticles were incorporated into an acrylate-based monomer system as the model …

Fabrication And Characterization Of Torsional Micro-Hinge Structures, Mike Madrid Marrujo

Master's Theses

ABSTRACT

Fabrication and Characterization of Torsional Micro-Hinge Structures

Mike Marrujo

There are many electronic devices that operate on the micrometer-scale such as Digital Micro-Mirror Devices (DMD). Micro actuators are a common type of DMD that employ a diaphragm supported by torsional hinges, which deform during actuation and are critical for the devices to have high stability and reliability. The stress developed within the hinge during actuation controls how the actuator will respond to the actuating force. Electrostatically driven micro actuators observe to have a fully recoverable non-linear viscoelastic response. The device consists of a micro-hinge which is suspended by two …

Development Of Low Temperature Alpha Alumina Coatings By Ac Magnetron Sputtering, Andrew Cloud

Mechanical Engineering Undergraduate Honors Theses

Alpha-phase aluminum oxide thin films were created using an Isoflux ICM-10 dual target inverted cylindrical magnetron sputtering system using mid-frequency AC power supplies. Alpha alumina films were deposited at a magnetron power of 6 kW, 50% oxygen partial pressure by volume, and -35 V DC bias. Film thickness, substrate material, and position and orientation within the deposition chamber were varied. To ensure the deposition conditions are suitable for alloys, the substrate temperature was measured using temperature indicating liquids. The experimental results, supported by Explicit Euler numerical analysis, revealed a steady state temperature of ~480°C at 6kW. Transmission electron microscopy (TEM) …