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Full-Text Articles in Semiconductor and Optical Materials

Development Of Hybrid Self-Cleaning Coating Using Lanthanide-Based Light Spectral Response Material To Enhance Photovoltaic (Pv) Panel Efficiency In Operational Environment, Khishn Kumar Kandiah May 2026

Development Of Hybrid Self-Cleaning Coating Using Lanthanide-Based Light Spectral Response Material To Enhance Photovoltaic (Pv) Panel Efficiency In Operational Environment, Khishn Kumar Kandiah

Student Works (2020-2029)

The efficiency of photovoltaic (PV) panels is crucial, as solar energy has become an alternative energy source that meets today’s global energy demands. Hence, dust accumulation and spectral mismatch have major effects on the efficiency of PV panels, around 20 %, but in extreme situations, this can reach up to 64 %. Therefore, initiatives are underway to address these issues, including PV cooling systems, conventional cleaning methods, and various coatings to enhance efficiency. In this work, a novel coating is fabricated with high transparency, excellent self-cleaning properties, and good spectral-modifying properties. Two types of powder composites are employed in this …


Molecular Diffusion In Chemically Amplified Resists For Euv Lithography, Eshan Dilina Thilakarathna Jan 2026

Molecular Diffusion In Chemically Amplified Resists For Euv Lithography, Eshan Dilina Thilakarathna

Electronic Theses & Dissertations (2024 - present)

Photolithography is a critical manufacturing step in high-volume manufacturing (HVM) of semiconductor devices, where a photoresist layer is used to transfer nanoscale patterns onto the underlying stack materials. As the microelectronics industry continues to move toward smaller node sizes, driven by Moore's Law. As a result, the tolerances for photoresist performance have become increasingly demanding, which necessitates simultaneous improvements in resolution, defectivity, and roughness. At advanced nodes, these performance limitations are governed by the fundamental stochastic nature of the photochemical processes occurring within the resist film itself, rather than the optical or tool-level constraints. Photon shot noise, the statistical distribution …


An Overview Of Biomass-Derived Graphene Oxide And Its Characteristics For Future Sustainable Applications, Afif Wardana, Ahmad Nabil Shahab, Donanta Dhaneswara, Nofrijon Sofyan Dec 2025

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 …


Preparation And Characterization Of Electrospun Pvdf-Based Nanocomposite Fibers For Energy Harvesting And Storage Applications, Ahmed Ramzy, Electrochemistry And Corrosion Laboratory, Physical Chemistry Department, National Research Centre, Dokki, Cairo, 12622, Egypt, Ahmed M. El-Mahalawy Jul 2025

Preparation And Characterization Of Electrospun Pvdf-Based Nanocomposite Fibers For Energy Harvesting And Storage Applications, Ahmed Ramzy, Electrochemistry And Corrosion Laboratory, Physical Chemistry Department, National Research Centre, Dokki, Cairo, 12622, Egypt, Ahmed M. El-Mahalawy

Nanotechnology Research Centre

This study introduces the development of multifunctional electrospun polyvinylidene fluoride (PVDF) composite films doped with potassium octatitanate (KTO) for advanced energy applications. The research tackles key challenges in energy generation and storage through innovative material design and detailed characterization. Adding 0.2 wt% KTO to PVDF electrospun fibers resulted in a notable increase in crystallinity to 78.51 %, marking a significant enhancement in material properties. Structural analysis using X-ray diffraction and Fourier transform infrared spectroscopy confirmed optimal phase composition, while morphological features were verified through field emission scanning electron microscopy. The composite films showed exceptional electrochemical performance, with bulk electrolyte resistance …


Advanced Manufacturing Of Multifunctional Shape Memory Polymer Composites And Self-Healing Systems, John B. Konlan Apr 2025

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 …


Growth Kinetics And Stability Of Metal Halide Perovskite Nanocrystals: Influence Of Stirring Speed And Water Exposure, You-Lin Huang Jan 2025

Growth Kinetics And Stability Of Metal Halide Perovskite Nanocrystals: Influence Of Stirring Speed And Water Exposure, You-Lin Huang

Theses and Dissertations--Mechanical and Aerospace Engineering

Cesium lead bromide (CsPbBr3) perovskite nanocrystals (NCs) have garnered significant interest due to their exceptional optoelectronic properties, including high photoluminescence quantum yield, tunable bandgap, and excellent carrier dynamics. These attributes make them promising candidates for applications in light-emitting diodes, photovoltaics, and sensing technologies. However, optimizing their synthesis and improving their environmental stability remain critical challenges. This dissertation explores the growth kinetics of CsPbBr3 NCs, focusing on the effects of stirring speed and water exposure on their structural and optical properties.

The synthesis of CsPbBr3 NCs was performed using both mechanochemical (MC) and antisolvent methods, enabling an …


Development And Structural Origin Of Stretchable Semiconducting Polymers And Composites, Yunfei Wang Aug 2024

Development And Structural Origin Of Stretchable Semiconducting Polymers And Composites, Yunfei Wang

Dissertations

Stretchable semiconductors are pivotal in advancing wearable and implantable electronics, with those boasting both high stretchability and self-healing capabilities being especially significant for a myriad of wearable applications. In this dissertation, we developed an extremely soft, highly stretchable, and self-healing elastomer based on H-bonding crosslinked amide-functionalized polyisobutylene (PIB-amide). When blended with a high-performance conjugated diketopyrrolopyrrole (DPP-T) polymer, the composite exhibits unprecedented stretchability, exceptionally low elastic modulus, and an innate ability to self-heal at room temperature.

The morphology of conjugated polymer/elastomer semiconducting composites have significant impacts on electrical and mechanical properties Further investigations focused on manipulating the phase separation size in …


Design, Fabrication And Characterization Of Zero Power Sensor/Harvester For Smart Grid Applications, Zeynel Guler Dec 2023

Design, Fabrication And Characterization Of Zero Power Sensor/Harvester For Smart Grid Applications, Zeynel Guler

Mechanical Engineering ETDs

This study presents a flexible sensor/harvester device to be used in both electromagnetic sensing and energy harvesting applications for smart grids. When a current passes through a wire, the sensor detects the magnetic field created by that current. The sensor magnet interacts with the wire magnetic field resulting in a transfer of energy through the piezoelectric cantilever. Piezoelectric, conductive, magnetic, and magnetostrictive composite thin films were prepared to fabricate this device.

Initially, the magnet of the cantilever was optimized considering its shape, thickness, length, taper angle etc. via both simulations and experiments. Peak to peak voltage versus cantilever position graph …


The Application Of Photoelectron Spectroscopies In Analyzing The Impact Of Interfacial Energetics On Perovskite Solar Cells, Tuo Liu Jan 2023

The Application Of Photoelectron Spectroscopies In Analyzing The Impact Of Interfacial Energetics On Perovskite Solar Cells, Tuo Liu

Theses and Dissertations--Chemistry

In recent years, organic-inorganic metal halide perovskites (HP) have garnered tremendous attention in photovoltaic research. This attention is attributed to their low cost and excellent optoelectronic properties, including large absorption coefficients, tunable bandgaps, long charge-carrier diffusion lengths, and low densities of deep trap states. Inverted p-i-n architecture perovskite solar cells (PSCs) are of intense interest and are generally regarded as more amenable to low-temperature solution processing. Nevertheless, the development of inverted PSCs is lagging the conventional architecture devices. Imperfect energy level alignments and charge carrier recombination, especially at the interface between perovskite and electron transport layers (ETLs), are two main …


Design, Fabrication, And Characterization Of Conjugated Polymeric Electrochemical Memristors As Neuromorphic/Integrated Circuits, Benjamin Grant Dec 2022

Design, Fabrication, And Characterization Of Conjugated Polymeric Electrochemical Memristors As Neuromorphic/Integrated Circuits, Benjamin Grant

All Dissertations

Organic materials are promising candidates for future electronic devices compared to the complementing inorganic materials due to their ease of processability, use, and disposal, low cost of fabrication, energy efficiency, and flexible nature toward implementation as flexible and non-conformal devices.With that in mind, electrochemical materials have been widely demonstrated with commercial use as sensors, displays, and a variety of other electronic devices. As Moore's law predicts the increase in the density of transistors on a chip, the requirement to create either smaller transistors or the replacement of the transistor device entirely is apparent. Memory resistors, coined ``memristor", are variable resistive …


Fabrication And Non-Covalent Functionalization And Characterization Of Graphene-Based Devices On Novel Substrate Cadmium Trithiophosphate (Iv) — Cdps, Abayomi Omotola Omolewu Aug 2022

Fabrication And Non-Covalent Functionalization And Characterization Of Graphene-Based Devices On Novel Substrate Cadmium Trithiophosphate (Iv) — Cdps, Abayomi Omotola Omolewu

Graduate Theses and Dissertations

With graphene at the center of several application areas such as sensing, circuits, high-frequency devices for communication systems, etc., it is crucial to understand how the intrinsic properties of devices made from graphene and other materials like platinum and palladium nanoparticles affect the performance of such devices for the specific application area. Many graphene-based devices for different application areas have focused mainly on the material composition of the graphene-based devices and how it affects performance parameters for the specific application. However, it would be insightful to understand how the intrinsic electrical properties of the graphene devices for different applications affect …


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 …


Simplified Synthesis Of Conjugated Polymers Enabled Via 1,4-Dihydropyrrolo[3,2-B]Pyrrole, Kenneth-John Jack Bell Apr 2022

Simplified Synthesis Of Conjugated Polymers Enabled Via 1,4-Dihydropyrrolo[3,2-B]Pyrrole, Kenneth-John Jack Bell

Master of Science in Chemical Sciences Theses

Conjugated polymers have attracted significant attention as the active layer material in organic electronics, such as organic photovoltaics and light-emitting diodes, partly due to the ability to influence a broad range of properties through structural design motifs. However, high performance conjugated polymers suffer from numerous synthetic steps, generation of toxic waste, and harsh reaction conditions all of which impart additional costs that inhibit their widespread utilization. Therefore, an emphasis on reducing synthetic complexity and utilizing abundant, commercially available starting materials is needed for organic electronics to reach their full potential. Dihydropyrrolo[3,2-b]pyrrole (H2DPP) chromophores offer a simple one-pot synthesis …


Thermomechanics Of Semiconducting Polymers And Their Morphological Phenomena, Luke Galuska Mar 2022

Thermomechanics Of Semiconducting Polymers And Their Morphological Phenomena, Luke Galuska

Dissertations

In contrast to conventional silicon-based electronics, semiconducting polymers show great promise for emerging applications in soft, flexible, and ductile electronic technologies. This is due to their polymeric nature, tailorable structure, and sub-100 nm device thickness. Despite this mechanical novelty, there remains a poor understanding of their structure-property-processing relationships, which has hindered growth within the field. This dissertation elucidates these relationships through investigation of their thermomechanics, and morphological phenomena. This was accomplished through the following projects:

1) To demonstrate the impact of backbone rigidity on semiconducting polymer thermomechanics, we varied the backbone rigidity of an NDI-based polymer by inserting flexible methylene …


Branched Chain Amino Acid Strain State Monitoring With Raman Spectroscopy And Plasmonic Bowtie Nanoantenna Devices For Early Disease Detection, Caroline A. Campbell Jan 2022

Branched Chain Amino Acid Strain State Monitoring With Raman Spectroscopy And Plasmonic Bowtie Nanoantenna Devices For Early Disease Detection, Caroline A. Campbell

Theses and Dissertations

This work centers on the development and the down-selection of nano-manufactured devices to be used in conjunction with Raman spectroscopy for probing a branched chain amino acid. The nano-manufactured devices integrate plasmonic nanoantennas for the purpose of amplifying molecular fingerprints, which are otherwise difficult to detect, through Surface Enhanced Raman Spectroscopy (SERS). Plasmonic nanostructures can be utilized for a variety of biomedical and biochemical applications to detect the characteristic fingerprint provided by Raman Spectroscopy. The nano-manufactured devices create an electric field that amplifies minute perturbations and raises the signal above background noise. This may provide a deeper understanding of signal …


Modeling, Fabrication, And Characterization Of Rf-Based Passive Wireless Sensors Composed Of Refractory Semiconducting Ceramics For High Temperature Applications, Kavin Sivaneri Varadharajan Idhaiam Jan 2022

Modeling, Fabrication, And Characterization Of Rf-Based Passive Wireless Sensors Composed Of Refractory Semiconducting Ceramics For High Temperature Applications, Kavin Sivaneri Varadharajan Idhaiam

Graduate Theses, Dissertations, and Problem Reports (ETD)

Real-time health monitoring of high temperature systems (>500oC) in harsh environments is necessary to prevent catastrophic events caused by structural failures, varying pressure, and chemical reactions. Conventional solid-state temperature sensors such as resistance temperature detectors (RTDs) and thermocouples are restricted by their operating environments, sensor dimensions and often require external power sources for their operation. The current work presents the research and development of RF-based passive wireless sensing technology targeting high temperatures and harsh environmental conditions. Passive wireless devices are generally classified as near-field and far-field devices based on the interrogation distance. Near-field sensors are placed at …


Investigation Of Optical And Structural Properties Of Gesn Heterostructures, Oluwatobi Gabriel Olorunsola Dec 2021

Investigation Of Optical And Structural Properties Of Gesn Heterostructures, Oluwatobi Gabriel Olorunsola

Graduate Theses and Dissertations

Silicon (Si)-based optoelectronics have gained traction due to its primed versatility at developing light-based technologies. Si, however, features indirect bandgap characteristics and suffers relegated optical properties compared to its III-V counterparts. III-Vs have also been hybridized to Si platforms but the resulting technologies are expensive and incompatible with standard complementary-metal-oxide-semiconductor processes. Germanium (Ge), on the other hand, have been engineered to behave like direct bandgap material through tensile strain interventions but are well short of attaining extensive wavelength coverage. To create a competitive material that evades these challenges, transitional amounts of Sn can be incorporated into Ge matrix to form …


Rapid Annealing Of Perovskite Solar Cell Thin Film Materials Through Intense Pulse Light., Amir Hossein Ghahremani Aug 2021

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 …


Characterization Of Gesn Semiconductors For Optoelectronic Devices, Hryhorii Stanchu May 2021

Characterization Of Gesn Semiconductors For Optoelectronic Devices, Hryhorii Stanchu

Graduate Theses and Dissertations

Germanium-tin alloys with Sn compositions higher than 8 at. % to 10 at. % have recently attracted significant interest as a group IV semiconductor that is ideal for active photonics on a Si substrate. The interest is due to the fact that while at a few percent of Sn, GeSn is an indirect bandgap semiconductor, at about 8 to 10 at. % Sn, GeSn transitions to a direct bandgap semiconductor. This is at first surprising since the solid solubility of Sn in Ge under equilibrium growth conditions is limited to only about 1 at. %. However, under non-equilibrium growth conditions, …


Nature-Inspired Material Strategies Towards Functional Devices, Sayantan Pradhan Jan 2021

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 …


Multi-Level Analysis Of Atomic Layer Deposition Barrier Coatings On Additively Manufactured Plastics For High Vacuum Applications, Nupur Bihari Jan 2021

Multi-Level Analysis Of Atomic Layer Deposition Barrier Coatings On Additively Manufactured Plastics For High Vacuum Applications, Nupur Bihari

Dissertations, Master's Theses and Master's Reports

While hardware innovations in micro/nano electronics and photonics are heavily patented, the rise of the open-source movement has significantly shifted focus to the importance of obtaining low-cost, functional and easily modifiable research equipment. This thesis provides a foundation of open source development of equipment to aid in the micro/nano electronics and photonics fields.

First, the massive acceptance of the open source Arduino microcontroller has aided in the development of control systems with a wide variety of uses. Here it is used for the development of an open-source dual axis gimbal system. This system is used to characterize optoelectronic properties of …


Development Of Light Actuated Chemical Delivery Platform On A 2-D Array Of Micropore Structure, Hojjat Rostami Azmand, Hojjat Rostami Azmand Jan 2021

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 …


Growth And Characterization Of Semiconductor Materials And Devices For Extreme Environments Applications, Abbas Sabbar Dec 2020

Growth And Characterization Of Semiconductor Materials And Devices For Extreme Environments Applications, Abbas Sabbar

Graduate Theses and Dissertations

Numerous industries require electronics to operate reliably in harsh environments, such as extreme high temperatures (HTs), low temperature (LT), radiation rich environments, multi-extreme, etc. This dissertation is focused on two harsh environments: HT and multi-extreme.

The first study is on HT optoelectronics for future high-density power module applications. In the power modules design, galvanic isolation is required to pass through the gate control signal, reject the transient noise, and break the ground loops. The optocoupler, which consists of a lighting emitting diode (LED) and photodetector (PD), is commonly used as the solution of galvanic isolation at room temperatures. There is …


Direct Solar Absorption Nanoparticle Doped Membranes For A Hybrid Membrane Distillation And Photovoltaic Cell, Alejandro Espejo Sanchez Dec 2020

Direct Solar Absorption Nanoparticle Doped Membranes For A Hybrid Membrane Distillation And Photovoltaic Cell, Alejandro Espejo Sanchez

Boise State University Theses and Dissertations

The growing demand for clean water supplies is driving the need for an innovative approach of water desalination. Developing a method for treating water with high salinities is possible with membrane distillation (MD). Additionally, MD is very attractive for pairing with solar energy due to the low temperature requirements. The integration of a membrane distillation system with a photovoltaic (PV) system will result in the co-production of electricity and clean water, thereby improving the economics of MD. Such a hybrid system will directly absorb thermal energy in the membrane for desalination while taking advantage of the spectrally selective nature of …


Enhancement Of Absorptance By Ultrafast Laser Pulse Shaping For Efficient Laser Processing Of Thin Polymers, Arifur Rahaman Jan 2020

Enhancement Of Absorptance By Ultrafast Laser Pulse Shaping For Efficient Laser Processing Of Thin Polymers, Arifur Rahaman

Electronic Theses and Dissertations, 2020-2023

Ultrashort-pulsed lasers have been used for high precision processing of a wide range of materials including dielectrics, semiconductors, metals, and polymers/polymer composites, enabling numerous applications ranging from micromachining, photonics to life sciences. However, there are challenges when applying this technology in the industry, which requires scale and throughput different from lab use. The goal of this research is to understand how ultrafast laser pulses interact with thin polymers/polymer composite materials and develop a method that is efficient for ultrafast laser processing of these materials. It is a common practice in industrial applications to run the laser at a high repetition …


Fabrication, Characterization And Applications Of Highly Conductive Wet-Spun Pedot:Pss Fibers, Ruben Sarabia Riquelme Jan 2020

Fabrication, Characterization And Applications Of Highly Conductive Wet-Spun Pedot:Pss Fibers, Ruben Sarabia Riquelme

Theses and Dissertations--Chemical and Materials Engineering

Smart electronic textiles cross conventional uses to include functionalities such as light emission, health monitoring, climate control, sensing, storage and conversion of energy, etc. New fibers and yarns that are electrically conductive and mechanically robust are needed as fundamental building blocks for these next generation textiles.

Conjugated polymers are promising candidates in the field of electronic textiles because they are made of earth-abundant, inexpensive elements, have good mechanical properties and flexibility, and can be processed using low-cost large-scale solution processing methods. Currently, the main method to fabricate electrically conductive fibers or yarns from conjugated polymers is the deposition of the …


Ab Initio Investigation On The Surface Chemistry Of Functionalized Titania Membranes, Evan Hyde Jan 2020

Ab Initio Investigation On The Surface Chemistry Of Functionalized Titania Membranes, Evan Hyde

Theses and Dissertations--Chemical and Materials Engineering

Titania (titanium dioxide) is a metal oxide which has recently been investigated as a photocatalyst, most commonly for use in hydrolysis, which absorbs mostly in the UV range. However, the range of absorption can be shifted to fall within the visible light range either by doping or by functionalizing the surface with atomic or molecular adsorbates. Over the course of this research, a series of Density Functional Theory (DFT) calculations are performed to ascertain the effects of these different methods on the photocatalytic performance of titania. While the effects of nitrogen doping and oxygen vacancies are well known, more recent …


Gravity-Drawing Flexible Silicone Filaments As Fiber Optics And Model Foldamers, Katherine Snell Jan 2020

Gravity-Drawing Flexible Silicone Filaments As Fiber Optics And Model Foldamers, Katherine Snell

CMC Senior Theses

Here, we present a method of gravity-drawing polydimethylsiloxane (PDMS) silicone fibers with application as fiber optics and as model foldamers. Beginning as a viscous liquid, PDMS is cured using heat until its measured viscosity reaches 4000 mPa•s. The semi-cured elastomer is then extruded through a tube furnace to produce thin (diameters on the order of hundred micrometers) filaments with scalable lengths. PDMS is biocompatible, gas-permeable, flexible, and hydrophobic. Additionally, the PDMS surface hydrophobicity can be modified via UV exposure, O2 plasma, and corona discharge. We demonstrate the patternibility (i.e patterns of hydrophobicity) of PDMS fibers, adding complexity to potential foldamer …


Interfaces In Lead-Free Tin Perovskite Photovoltaics: An Investigation Of Energetics, Ion Mobility, Surface Modification, And Performance, Alex Boehm Jan 2020

Interfaces In Lead-Free Tin Perovskite Photovoltaics: An Investigation Of Energetics, Ion Mobility, Surface Modification, And Performance, Alex Boehm

Theses and Dissertations--Chemistry

Halide perovskites have generated tremendous interest as low-cost semiconductors for optoelectronics, such as photovoltaics, lasers, and light emitting diodes due to their extraordinary optical and transport properties. Perovskite photovoltaics in particular have demonstrated a meteoric rise in power conversion efficiencies and drawn considerable interest as a next-generation solar energy technology. The rapid development has centered around lead-based derivatives, and concerns regarding the toxicity of lead has sparked interest in low toxicity and more environmentally friendly perovskite derivatives. In this regime tin (Sn) is regarded as a prominent alternative owing to the ideal bandgap and reduced toxicity exhibited by Sn-halide perovskites. …


Maximizing Poly(3-Butylthiophene-2,5-Diyl) Electrical Conductivity By Maximizing Transcrystal Growth, Edward Alexander Bicknell Jun 2019

Maximizing Poly(3-Butylthiophene-2,5-Diyl) Electrical Conductivity By Maximizing Transcrystal Growth, Edward Alexander Bicknell

Materials Engineering

Polymers are generally considered electrical insulators. Despite this, research in the mid 1970’s found that polymers consisting of a conjugated backbone structure could become electrically conductive upon doping.1 The conjugated polymer analyzed for this project was poly(3-butylthiophene-2,5-diyl) (P3BT). Transcrystals have been found as a way to promote electrical conductivity through mechanisms including π bond atomic orbital overlap and electron mobility.2 In theory, maximizing transcrystal length would also maximize P3BT electrical conductivity, increasing its applicable use in electronic devices. The goal of this project was to determine a methodological way to maximize P3BT electrical conductivity by producing the longest transcrystal length …