Novel Organic Materials for Light Emitting Diodes and Neuromorphic Devices

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Description
Organic materials have emerged as an attractive component of electronics over the past few decades, particularly in the development of efficient and stable organic light-emitting diodes (OLEDs) and organic neuromorphic devices. The electrical, chemical, physical, and optical studies of organic

Organic materials have emerged as an attractive component of electronics over the past few decades, particularly in the development of efficient and stable organic light-emitting diodes (OLEDs) and organic neuromorphic devices. The electrical, chemical, physical, and optical studies of organic materials and their corresponding devices have been conducted for efficient and stable electronics. The development of efficient and stable deep blue OLED devices remains a challenge that has obstructed the progress of large-scale OLED commercialization. One approach was taken to achieve a deep blue emitter through a color tuning strategy. A new complex, PtNONS56-dtb, was designed and synthesized by controlling the energy gap between T1 and T2 energy states to achieve narrowed and blueshifted emission spectra. This emitter material showed an emission spectrum at 460 nm with a FWHM of 59 nm at room temperature in PMMA, and the PtNONS56-dtb-based device exhibited a peak EQE of 8.5% with CIE coordinates of (0.14, 0.27). A newly developed host and electron blocking materials were demonstrated to achieve efficient and stable OLED devices. The indolocarbazole-based materials were designed to have good hole mobility and high triplet energy. BCN34 as an electron blocking material achieved the estimated LT80 of 12509 h at 1000 cd m-2 with a peak EQE of 30.3% in devices employing Pd3O3 emitter. Additionally, a device with bi-layer emissive layer structure, using BCN34 and CBP as host materials doped with PtN3N emitter, achieved a peak EQE of 16.5% with the LT97 of 351 h at 1000 cd m-2. A new neuromorphic device using Ru(bpy)3(PF6)2 as an active layer was designed to emulate the short-term characteristics of a biological synapse. This memristive device showed a similar operational mechanism with biological synapse through the movement of ions and electronic charges. Furthermore, the performance of the device showed tunability by adding salt. Ultimately, the device with 2% LiClO4 salt shows similar timescales to short-term plasticity characteristics of biological synapses.
Date Created
2021
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Prenatal Supplementation Research

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Description
When viewing vitamins and minerals, it is seen that they are essential for human life and vital for pregnancy. When paired with a healthy diet, prenatal supplements can allow for a healthy pregnancy and reduced maternal and infant health problems.

When viewing vitamins and minerals, it is seen that they are essential for human life and vital for pregnancy. When paired with a healthy diet, prenatal supplements can allow for a healthy pregnancy and reduced maternal and infant health problems. Within this thesis, I was able to break down each vitamin and mineral necessary for a healthy pregnancy and birth. Further, I had the opportunity to dive into the addition of Omega-3 Fatty Acid during pregnancy to add more evidence to the study.
Date Created
2020-12
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Replacing Labels with Hope: The Study of a Learning Difference Mentorship Program

Description
Introduction: The Eye to Eye mentorship program is a national program in which college or high school students with learning differences mentor middle school students with learning differences. There are 68 Eye to Eye programs around the country, but little

Introduction: The Eye to Eye mentorship program is a national program in which college or high school students with learning differences mentor middle school students with learning differences. There are 68 Eye to Eye programs around the country, but little research has been done on their effectiveness and how to improve it. We conducted and evaluated one program site at Arizona State University and implemented this mentorship program for the first time during 2019. We hypothesized the Eye to Eye mentorship program that paired college students who have learning differences with middle school students who have similar learning differences would improve the outcomes and socio-behavior skills of both mentors and mentees.

Methods: The Eye to Eye mentorship program assessed involved mentors and mentees who completed 12 in-person art sessions out of the normal 20 in-person sessions. The first main assessment was the BLD (Breger Learning Difference) Feedback Survey addressing one’s experience in the Eye to Eye program and which were completed at the end of the mentorship program and filled out by mentors, mentees, and mentees parents (one parent for each mentee). A total of 12 mentors, 6 mentees, and 6 mentee parents were included in the feedback survey final analysis. The second main assessments were the pre and post Behavior Assessment System for Child, Third Edition (BASC-3) provided to mentors, mentees, and mentees parents (one parent for each mentee). A total of 10 mentors, 5 mentees, and 5 mentee parents were included in pre and post BASC-3 final analysis. Fall 2019 (pre) and Spring 2020 (post) optional interviews involved 5 mentors and 3 mentees who showed interest and were comfortable participating with additional release forms.

Results: The program was generally positively rated in the feedback survey by mentors, mentees, and mentee parents. The highest responses for mentors, mentees, and mentee parents all incorporated average ratings of 4.0 or higher (out of 5.0) for perceived understanding of socio-emotional skills after Eye to Eye, experience in Eye to Eye, how having a mentor or mentee made them feel, and perceived change in self-awareness. All three groups reported fairly high ratings of improved self-awareness of 4.0/5.0 or above. No negative ratings were provided by any participants and the lowest response was no change. The BASC-3 evaluation found statistically significant improvement in mentors’ anxiety and atypicality and mentees’ sense of inadequacy.

Discussion: The Eye to Eye program was popular and well-rated despite only involving 12 in- person one-hour art sessions. The mentors, mentees, and mentee parents felt positive about the Eye to Eye program when answering the feedback survey. Some suggestions are made on how to improve this program to better enhance someone with learning differences future ability to succeed. Future research is needed to assess the true impact due to the COVID-19 epidemic and other limitations.
Date Created
2020-05
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High-performance organic light emitting diodes

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Description
Organic electronics have remained a research topic of great interest over the past few decades, with organic light emitting diodes (OLEDs) emerging as a disruptive technology for lighting and display applications. While OLED performance has improved significantly over the past

Organic electronics have remained a research topic of great interest over the past few decades, with organic light emitting diodes (OLEDs) emerging as a disruptive technology for lighting and display applications. While OLED performance has improved significantly over the past decade, key issues remain unsolved such as the development of stable and efficient blue devices. In order to further the development of OLEDs and increase their commercial potential, innovative device architectures, novel emissive materials and high-energy hosts are designed and reported.

OLEDs employing step-wide graded-doped emissive layers were designed to improve charge balance and center the exciton formation zone leading to improved device performance. A red OLED with a peak efficiency of 16.9% and an estimated LT97 over 2,000 hours at 1,000 cd/m2 was achieved. Employing a similar structure, a sky-blue OLED was demonstrated with a peak efficiency of 17.4% and estimated LT70 over 1,300 hours at 1,000 cd/m2. Furthermore, the sky-blue OLEDs color was improved to CIE coordinates of (0.15, 0.25) while maintaining an efficiency of 16.9% and estimated LT70 over 600 hours by incorporating a fluorescent sensitizer. These devices represent literature records at the time of publication for efficient and stable platinum phosphorescent OLEDs.

A newly developed class of emitters, metal-assisted delayed-fluorescence (MADF), are demonstrated to achieve higher-energy emission from a relatively low triplet energy. A green MADF device reaches a peak efficiency of 22% with an estimated LT95 over 350 hours at 1,000 cd/m2. Additionally, a blue charge confined OLED of PtON1a-tBu demonstrated a peak efficiency above 20%, CIE coordinated of (0.16, 0.27), and emission onset at 425 nm.

High triplet energy hosts are required for the realization of stable and efficient deep blue emission. A rigid “M”-type carbazole/fluorene hybrid called mDCzPF and a carbazole/9-silafluorene hybrid called mDCzPSiF are demonstrated to have high triplet energies ET=2.88 eV and 3.03 eV respectively. Both hosts are demonstrated to have reasonable stability and can serve as a template for future material design. The techniques presented here demonstrate alternative approaches for improving the performance of OLED devices and help to bring this technology closer to widespread commercialization.
Date Created
2019
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2D or Not To Be: The Story and Science of Graphene

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Description
The story of graphene truly began in what was simply a stub in the journal Physical Review not two years after the end of World War II. In 1947, McGill University physicist P.R. Wallace authored “The Band Theory of Graphite”

The story of graphene truly began in what was simply a stub in the journal Physical Review not two years after the end of World War II. In 1947, McGill University physicist P.R. Wallace authored “The Band Theory of Graphite” and attempted to develop a foundation on which the structure-property relationship of graphite could be explored; he calculates the number of free electrons and conductivity of what he describes as “a single hexagonal layer” and “suppos[es] that conduction takes place only in layers” in bulk graphite to predict wave functions, energies at specific atomic sites in the hexagonal lattice, and energy contours using a tight binding approximation for a hypothesized version of what we now call ‘armchair-style’ graphene. While Wallace was the first to explore the band structure and Brillouin Zones of single-layer graphite, the concept of two-dimensional materials was not new. In fact, for years, it was dismissed as a thermodynamic impossibility.

Everything seemed poised against any proposed physical and experimental stability of a structure like graphene. “Thermodynamically impossible”– a not uncommon shutdown to proposed novel physical or chemical concepts– was once used to describe the entire field of proposed two-dimensional crystals functioning separately from a three-dimensional base or crystalline structure. Rudolf Peierls and Lev Davoidovich Landau, both very accomplished physicists respectively known for the Manhattan Project and for developing a mathematical theory of helium superfluidity, rejected the possibility of isolated monolayer to few-layered crystal lattices. Their reasoning was that diverging thermodynamic-based crystal lattice fluctuations would render the material unstable regardless of controlled temperature. This logic is flawed, but not necessarily inaccurate– diamond, for instance, is thermodynamically metastable at room temperature and pressure in that there exists a slow (i.e. slow on the scale of millions of years) but continuous transformation to graphite. However, this logic was used to support an explanation of thermodynamic impossibility that was provided for graphene’s lack of isolation as late as 1979 by Cornell solid-state physicist Nathaniel David Mermin. These physicists’ claims had clear and consistent grounding in experimental data: as thin films become thinner, there exists a trend of a decreasing melting temperature and increasing instability that renders the films into islands at somewhere around ten to twenty atomic layers. This is driven by the thermodynamically-favorable minimization of surface energy.
Date Created
2018-05
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Environmental Impact of Graphene's Adoption into Everyday Life

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Description
Graphene has the ability to advance many common fields, including: membranes, composites and coatings, energy, and electronics. For membranes, graphene will be used as a filter for desalination plants which will reduce the cost of desalination and greatly increase water

Graphene has the ability to advance many common fields, including: membranes, composites and coatings, energy, and electronics. For membranes, graphene will be used as a filter for desalination plants which will reduce the cost of desalination and greatly increase water security in developing countries. For composites and coatings, graphene's strength, flexibility, and lightweight will be instrumental in producing the next generation of athletic wear and sports equipment. Graphene's use in energy comes from its theorized ability to charge a phone battery in seconds or an electric car in minutes. Finally, for electronics, graphene will be used to create faster transistors, flexible electronics, and fully integrated wearable technology.
Date Created
2018-05
Agent

Design and Testing of Cold-Extruded High-Density Polyethylene for Student Oboe Reeds and A Qualitative Comparison of Synthetic and Cane Oboe Reeds

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Description
This is a two-part thesis, completed in conjunction with my Materials Science and Engineering Capstone Project. The first part involves the design and testing of cold-extruded high-density polyethylene for student oboe reeds. The goal of this section was to create

This is a two-part thesis, completed in conjunction with my Materials Science and Engineering Capstone Project. The first part involves the design and testing of cold-extruded high-density polyethylene for student oboe reeds. The goal of this section was to create a longer-lasting reed that produces a similar sound to a cane reed, has less variation in quality, and costs less per year than cane reeds. For low-income students in particular, the cost of purchasing cane oboe reeds ($500-$2,000 per year) is simply not feasible. This project was designed to allow oboe to be a more affordable option for all students. Money should not be a factor that limits whether or a not a child is able to explore their interests. The process used to create the synthetic reed prototype involves cold-extrusion of high-density polyethylene in order to induce orientation in the polymer to replicate the uniaxial orientation of fibrous cane. After successful cold-extrusion of a high-density polyethylene (HDPE) cylinder, the sample was made into a reed by following standard reedmaking procedures. Then, the HDPE reed and a cane reed were quantitatively tested for various qualities, including flexural modulus, hardness, and free vibration frequency. The results from the design project are promising and show a successful proof of concept. The first prototype of an oriented HDPE reed demonstrates characteristics of a cane reed. The areas that need the most improvement are the flexural modulus and the stability of the higher overtones, but these areas can be improved with further development of the cold-extrusion process. The second part of this thesis is a survey and analysis focusing on the qualitative comparison of synthetic and cane oboe reeds. The study can be used in the future to refine the design of synthetic reeds, more specifically the cold-extruded high-density polyethylene student oboe reed I designed, to best replicate a cane reed. Rather than approaching this study from a purely engineering mindset, I brought in my own experience as an oboist. Therefore, the opinions of oboists who have a wide range of experience are considered in the survey. A panel of five oboists participated in the survey. They provided their opinion on various aspects of the five reeds, including vibrancy, response, stability, resistance, tone, and overall quality. Each of these metrics are rated on a scale from one to five, from unacceptable to performance quality. According to the survey, a participant's personal, hand-made cane reed is overall the most preferred option. My prototype HDPE student reed must be improved in many areas in order to rank near the other four reeds. However, its vibrancy and resistance already rival that of a Jones student reed. As this is just the first prototype, that is a significant accomplishment. With further refinement of the cold-extrusion and reedmaking method, the other areas of the HDPE reed may be improved, and the reed may eventually compete with the existing synthetic and cane reeds on the market.
Date Created
2018-05
Agent

Analysis of Yeast and Fungi in Children with ASD vs. Neurotypical Controls

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Description
The gastrointestinal (GI) tract is home to a complex and diverse microbial ecosystem that contributes to health or disease in many aspects. While bacterial species are the majority in the GI tract, their cohabitants, fungal species, should not be forgotten.

The gastrointestinal (GI) tract is home to a complex and diverse microbial ecosystem that contributes to health or disease in many aspects. While bacterial species are the majority in the GI tract, their cohabitants, fungal species, should not be forgotten. Children with autism spectrum disorder (ASD) often suffer from GI disorders and associated symptoms, implying a role the bacterial and fungal gut microbiota play in maintaining human health. The irregularities in GI symptoms can negatively affect the overall quality of life or even worsen behavioral symptoms the children present. Even with the increase in the availability of next-generation sequencing technologies, the composition and diversities of fungal microbiotas are understudied, especially in the context of ASD. We therefore aimed to investigate the gut mycobiota of 36 neurotypical children and 38 children with ASD. We obtained stool samples from all participants, as well as autism severity and GI symptom scores to help us understand the effect the mycobiome has on these symptoms. By targeting the fungal internal transcribed spacer (ITS) and bacterial 16S rRNA V4 regions, we obtained fungal and bacterial amplicon sequences, from which we investigated the diversities, composition, and potential link between two different ecological clades. From fungal amplicon sequencing results, we observed a significant decrease in the observed fungal OTUs in children with ASD, implying a lack of potentially beneficial fungi in ASD subjects. We performed Bray-Curtis principal coordinates analysis and observed significant differences in fungal microbiota composition between the two groups. Taxonomic analysis showed higher relative abundances of Candida , Pichia, Penicillium , and Exophiala in ASD subjects, yet due to a large dispersion of data, the differences were not statistically significant. Interestingly, we observed a bimodal distribution of Candida abundances within children with ASD. Candida's relative abundance was not significantly correlated with GI scores, but children with high Candida relative abundances presented significantly higher Autism Treatment Evaluation Checklist (ATEC) scores, suggesting a role of Candida on ASD behavioral symptoms. Regarding the bacterial gut microbiota, we found marginally lower observed OTUs and significantly lower relative abundance of Prevotella in the ASD group, which was consistent with previous studies. Taken together, we demonstrated that autism is closely linked with a distinct gut mycobiota, characterized by a loss of fungal and bacterial diversity and an altered fungal and bacterial composition.
Date Created
2018-05
Agent

Review of Autism Treatment Research

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Description
As the prevalence and awareness of Autism Spectrum Disorder (ASD) increases, so does the variety of treatment options for primary symptoms (social interaction, communication, behavior) and secondary symptoms (anxiety, hyperactivity, GI problems, and insomnia). Various treatments, from Adderall to Citalopram

As the prevalence and awareness of Autism Spectrum Disorder (ASD) increases, so does the variety of treatment options for primary symptoms (social interaction, communication, behavior) and secondary symptoms (anxiety, hyperactivity, GI problems, and insomnia). Various treatments, from Adderall to Citalopram to Flax Seed Oil promise relief for these symptoms. However, very little research has actually been done on some of these treatments. Additionally, the research that has been done fails to compare these treatments against one another in terms of symptom relief. The Autism Treatment Effectiveness Survey, written by Dr. James Adams, director of the Autism/Asperger's Research Program at ASU, and graduate student/program coordinator Devon Coleman, aims to fill this gap. The survey numerically rates medications based on benefit and adverse effects, in addition to naming specific symptoms that are impacted by the treatments. However, the survey itself was retrospective in nature and requires further evidence to support its claims. Therefore, the purpose of this research paper is to evaluate evidence related to the results of the survey. After the performing an extensive literature review of over 70 different treatments, it appears that the findings of the Autism Treatment Effectiveness Survey are generally well supported. There were a few minor discrepancies regarding the primary benefitted symptom, but there was not enough of a conflict to discount the information from the survey. As research is still ongoing, conclusions cannot yet be drawn for Nutritional Supplements, although the current data looks promising.
Date Created
2018-05
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Effect of Dietary/Nutritional Treatment on Symptoms of Autism

Description
Autism Spectrum Disorder is a disorder that makes learning, socializing and daily living much more challenging for affected children and adults because of their atypical behaviors. A few examples of these behaviors are repetitive movements, impulsive actions, inability to communicate

Autism Spectrum Disorder is a disorder that makes learning, socializing and daily living much more challenging for affected children and adults because of their atypical behaviors. A few examples of these behaviors are repetitive movements, impulsive actions, inability to communicate in a social setting, and many more. There is a stigma behind autism that is caused by those who are not well informed on the disorder. These people lack information, and in the past, it was assumed that the disorder is caused by "bad parenting." The parents are then afraid of social shame brought upon them by their child and neglect or avoid a diagnosis for their child's disorder. This becomes a vicious cycle that has negative effects on the affected individuals and their loved ones. Neglect of a diagnosis may also be caused by misinformation interpreted by the parents as their child develops. The parents do not realize this child developing outside of normal behavioral patterns. Years of research have been done to attempt to alleviate the symptoms of autism and cure the disorder. The Autism and Asperger's Program at ASU has developed a year-long dietary plan that increases supplementation to alleviate nutritional deficiencies in participants with autism. These deficiencies include vitamins, minerals, essential fatty acids, sulfate, carnitine, and digestive enzymes such as sucrase, maltase, and lactase. The participants were also put on a gluten-free casein-free diet toward the end of the study. To test the effectiveness of the treatment, the Severity of Autism Scale (SAS) and Social Responsiveness Scales (SRS) were used. The SAS tested the overall severity of ASD participants by rating them from one to ten, ten being "very severe" in terms of ASD symptoms. The results of this scale were compared at the beginning of the study (day 0) and at the end of the study (day 365). The SRS tested the social responsiveness of participants in the form of overall SRS and five subscales that included awareness, cognition, communication, motivation, and mannerisms. These results were also compared at the beginning and end of the study. After analysis of the data, there seemed to be no correlation between age and severity of autism/social responsiveness of participants. There was also no statistically significant data to suggest that there was a correlation between gender and severity of autism/social responsiveness of participants. However, there was statistically significant evidence that the treatment group did improve over the non-treatment/delayed treatment group in both the SAS and SRS. Neither age nor gender had a significant effect on the effectiveness of the treatment. These positive findings suggest that the integrated dietary
utritional therapy was beneficial, and future research on dietary treatments for autism and other disorders is recommended. This may also further discoveries of affected epigenomes with regards to nutritional treatments in disorders like ASD. The epigenome is the methylation and demethylation of the genome that mediates gene expression.
Date Created
2016-05
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