471,653 Works

Atomic-scale characterization of CdTe PV through atom probe tomography

Kevin S. Boxer, Brian Gorman & Teresa Barnes
CdTe solar cell technology uses a thin film photovoltaic device, which has become increasingly cost competitive, with the potential to reduce the use of fossil fuels with a favorable balance of cost and efficiency. Atom probe tomography lets us use a local electrode atom probe and laser-induced field evaporation to discover the chemical composition measurements at the atomic scale and with 3D imaging and analysis. Future work could entail performing additional APT trials with variations...

Raman spectroscopy of silicon quantum dots

Kurchin Rachel, Chito Kendrick, Reuben Collins & Thomas Furtak
Silicon quantum dots are synthesized and studied extensively by REMRSEC, but they have not thus far had a fast and reliable way to characterize them. In this work, Raman spectroscopy is employed to study dots in varying types of samples, with special attention paid to the effects excessive laser power density can have on amorphous silicon.

Synthesis of earth-abundant and nontoxic nanomaterials for sustainable energy: colloidal 3C-SiC quantum dots through a room temperature bottom-up method

Malcolm Davidson, Jaqueline E. Cloud & Yongan Yang
Motives for Silicon Carbide Quantum Dots: Enhanced intensity and chromatic quality as LED's; High intensity emission and low toxicity as biomarker candidates; Size dependent band gap; Applications in photo-electrolysis of water, reduction of organics for self cleaning surfaces, light harvesting components for hybrid and classic solar cells.

Facile method for making monodispersed colloidal plantinum nanocrystals, A

Kyle Snow, Kevin McCann & Yongan Yang
Platinum nanoparticles are extremely small clusters of Pt atoms, usually 1-50 nanometers (nm) in width, homogeneously dispersed in a colloidal solution. Pt nanoparticles have excellent catalytic strength, even more so than bulk platinum. This is due to nanoparticles' high surface area to volume ratio. Shape also plays a large role in particle functionality. Pt nanoparticles by themselves have a high tendency to agglomerate, which hinders their effectiveness. For this reason, molecules called ligands are used...

Deformation of indium oxide nanostructures, The

Stephanie Gomez, Mukesh Kumar & Corrine E. Packard
The development of nanowire technology is important for the application of small and compact devices to replace bulk material and has been a subject of great interest due to their potential in advancing field effect transistors. Nanowires are better for transistor devices because they are a single crystal grown from the bottom-up approach and thus allowing for a controlled gate length. Understanding the mechanical properties will determine the reliability of the nanowire devices.

Renewable energy and climate change education

Kelsey Kawaguchi, Cynthia Howell, Junko Munakata-Marr & Carl Mitcham
To identify barriers to incorporating climate change (CC) education into high school and community college courses, 24 national educators were interviewed. During each 30-minute recording, instructors described experiences with: (1) what courses are taught, (2) the depth of CC coverage, (3) what was the motivation to include CC, (4) opportunities for CC education in the future, (5) ultimate barriers to incorporating CC, (6) how CC is discussed and/or considered, (7) how CC can be a...

Horizontal deposition of polystyrene colloids for enhanced light trapping in solar cells

Kento Omkamoto, Ning Wu & Fuduo Ma
Motivations: A majority of solar cells base their materials off of silicon wafers about 180-300 microns in thickness due to it being very cost efficient in the market. However, when the thickness of silicon wafers are reduced, they are only able to create energy on the visible light spectrum for solar rays. Because light on the infrared spectrum is not effectively absorbed when making thinner silicon wafers, a proposal to implement metal particles into the...

Using AFM to find evidence of conformal monolayers

Erich Meinig, Thomas Brenner, Gang Chen, Reuben Collins & Thomas Furtak
Atomic force microscopy (AFM) is one of the tools used to infer whether a conformal monolayer of the surface treatment exists. AFM roughness measurements can be used to detect changes in height before and after surface treatment. This work aimed to measure the existence of such layers.

Spatial frequency modulation for imaging (SPIFI) in optical and mid-IR wavelength systems

Nicole Johnson, Jaime Corchado, Jeff Squier & Eric Toberer
This work aims to use a single element detector for 2D imaging. The work uses frequency encoding to eliminate the need to scan in the direction of line focus and it uses a Fourier transform detector signal to recover frequency space representation of the object.

Centrifugal sieving for the size separation of lunar regolith in microgravity

Myles Martinez, John Fruit, Christopher Dreyer, Otis Walton & Ned Riedel
For any microgravity environment traditional sieving methods used on earth can fail or be less effective for smaller size particles. Previously a device was designed and built that uses centrifugal force created by a spinning screen to push material through and a spinning helical auger to create shear flow to sieve independent of gravity. Power consumption of the motors was monitored via two ammeters and blinding of the screen was monitored regularly with a camera...

Quantitative infrared spectroscopy of ionic liquids

David A. Bicknase, Jason Porter & Chris B. Dreyer
To make quantitative optical absorption measurements of ionic liquids. Quantitative spectroscopic measurements will allow for the development of optical diagnostics for in-situ testing of purity during synthesis, of impurities in battery applications due to breakdown of an ionic liquid, and of ionic liquid purity before use. In order to obtain quantitative spectroscopic measurements a FTIR spectrometer and thin-film cell are used. To accurately determine the thickness of the ionic liquid sample, the path length between...

Novel bimetallic catalysts for use in anion exchange membrane fuel cells

Nicholas A. Sather, James M. Ham, Andrew M. Herring & Lauren F. Greenlee
Widespread implementation of current fuel cell technology is inhibited by the scarcity and price of the catalysts on both the anode and cathode. However, recent research suggests that Alkaline Anion Exchange Membrane Fuel Cells (AAEMFC) can operate with earth abundant materials as catalysts due to the rapid reaction kinetics in alkaline environments. This research investigates the electrocatalytic properties of a novel bimetallic catalyst in the oxidation of methanol, ethanol and methane fuels for use in...

Micro-scale mechanical properties of NMC lithium ion battery cathodes

Matt Musselman, Taylor Wilkinson, Kandler Smith & Corinne Packard
This work aims to update current lithium ion battery lifetime models in order to provides more accurate predictions on batteries for use in electric/hybrid cars. This requires new physics-based models and an understanding of mechanical degradation factors of NMC particles and the properties of each component over the life span. Thus, this work will measure the mechanical properties of individual particles using nanoindentation to develop a better understanding of the fundamental material physics behind battery...

Renewable energy applications for oil shale drilling

Violaine Salomon
Extracting oil shale requires a large amount of energy for heating and pyrolyzing the rock. Using renewable energy sources is a good opportunity to reduce the overall carbon footprint. This poster details thermal solar as an energetic solution and compares different renewable energy sources, as well as their consumption water, greenhouse gas emissions and embodied energies. All the calculations are based on energy calculations to extract 100,000 barrels of oil shale per day of rich...

Altering shear thickening of chemical mechanical polishing slurries through the addition of electrolytes and organic solvents

Benjamin Yohe, Nathan Crawford, Matthew Liberatore & Kim Williams
Chemical mechanical polishing (CMP) planarizes and polishes semiconducting materials commonly used in microelectronics. The CMP process depends highly on the slurry composition, particle size and concentration, pH, and added chemicals, which determine the slurry's stability and effectiveness. During the CMP process, the slurry film thickness (between the polishing pad and wafer surface) can vary. It is hypothesized that particles agglomerate during the polishing process, leading to structural damages on the wafer surface (i.e., scratches, gouges,...

Renewable energy applications for oil shale production

Elsa Robles
To reduce the environmental impact of oil shale extraction it would be valuable to use renewable energy sources to provide power to heat the oil shale. This poster presents analysis of different renewable resources that could be used to provide this energy. This work is based on calculations by Alan Burnham of American Shale Oil (AMSO) of how much power is needed to extract 100,000 barrels per day for a medium oil shale (20gal/ton) and...

Vertical alignment of gold nanorods with AC voltage

Lois Smith & Ning Wu
The ability to easily and efficiently align nanorods would improve solar cells and sensors by leaps and bounds. We choose Au nanorods as a model system and studied their alignment under an electric field. The alignment of semiconductor nanorods perpendicular to the substrate has been previously accomplished using evaporation techniques and DC voltage, yet vertical uniform alignment of Au nanorods has not been achieved. Thus, we decided to experiment with AC voltage to find a...

NMR analysis of passivated silicon quantum dots

Blaire Sorenson, Yongan Yang, Jifang Cheng & Kim R. Williams
The increased demand for energy calls for the development of new approaches towards renewable energy sources. Solar energy is one of the most abundant energy resources that can be converted to thermal, chemical and electrical energy. The demand to increase solar energy production to the terra watt level motivated our project, and our research focused on better efficiency of photovoltaics. Silicon is the most developed semi-conductor in the world and because it has been well...

Renewable energy and climate change education

Abigail Azari
In order to address the challenges in the infusion of climate change science into high school and community college renewable energy course offerings, this study focused on administrators and faculty of community colleges and high schools. Nineteen community college and four high school instructors in a Sustainable Energy Education Training (S.E.E.T.) workshop were interviewed regarding the challenges of designing courses that include climate change. The interviews addressed barriers and opportunities for effective integration of climate...

Photoluminescence quenching and hot carrier transfer in nanocrystalline silicon

Levi Miller, Jeremy Fields, Reuben Collins & Craig Taylor
The maximum efficiency of silicon photovoltaic cell is not 31% but 74%. Collecting hot carriers before they thermalize is a means to achieve this. In this regard, amorphous semiconductors are potentially useful materials. Nanocrystalline silicon (nc-Si:H) is unique in that carriers of wide energy distribution generated in amorphous regions may be in range of crystalline regions. These carriers can benefit from higher mobility and a lesser probability of thermalization. The motivation behind this project is...

Chemical bath deposition of hematite nanostructures for photo-electrochemical water splitting

Alex Sale, Rachel Morrish & Colin A. Wolden
Storing solar energy in the form of chemical bonds presents a sustainable approach to meet future energy demands. However, improvements in efficiency and cost are needed before photo-electrochemical (PEC) water splitting can be practically utilized. Hematite has emerged as a promising material for PEC hydrogen generation. The advantages of hematite include its ideal band gap and that it is cheap, earth abundant and chemically stable. The challenges of hematite include low photocurrents, short h+ diffusion...

Effect of environmental aging on the mechanical properties of PMMA material used in concentrating photovoltaics, The

Joseph Carloni, Taylor M. Wilkinson, David C. Miller & Corinne E. Packard
Concentrating photovoltaics (CPV) modules use focused light. A frensed lens requires less material and is lighter than a bulky and expensive traditional domed lens. A promising lens material is poly(methyl methacrylate) or PMMA. This polymer is a lightweight and mechanically robust optical grade material, benefitting the CPV application. It is relatively unknown how its performance will be affected by environmental weathering conditions. An ATLAS Ci-4000 Weather-Ometer simulates environmental wreathing at >8x acceleration. The samples tested...

Successive ionic layer adsorption and reaction for organic/inorganic interfaces

Heather Hunt, Reuben Collins & Thomas Furtak
Zinc oxide is a promising material for use in organic electronics, particularly organic photovoltaics (OPVs). ZnO has a large band gap around 3.3 eV, has a high electron mobility, is non-toxic, and can be processed using solution based methods at atmospheric and room temperature conditions. It has gathered attention in OPVs because it can be used as an electron acceptor at its interface with organic hole conducting molecules. ZnO can also be used as a...

Synthesis and characterization of Br- and Cl- anion exchange membranesfor use in alkaline polymer electrolyte fuel cells

Emily Tansey, Andrew M. Herring, James L. Horan & Melissa Vandiver
Proton exchange membrane (PEM) fuel cells utilize pure hydrogen fuel and platinum-based catalysts. Hydrogen has a relatively low energy density, so large-scale fuel storage is required to operate PEMs. Pt-based catalysts further constrict the manufacturability of PEMs due to scarcity of platinum. As a fuel source, methanol has a greater energy density than hydrogen; however, as PEMs require H+ ionic transport, a fuel processor must be included with the fuel cell assembly to convert CH3OH...

Plasma enhanced chemical vapor deposition synthesis of metal carbide membranes for high temperature H2 separations

Donal Finegan, Mayur Ostwal, James Douglas Way & Colin Wolden
Approximately 80% of the global energy demand comes from fossil fuels and this reliance is expected to increase at least until the year 2020. Combustion of these fossil fuels to generate power produces CO2. Hydrogen gas is a highly sought after chemical within industry and its uses in society are continuously increasing. The annual production of H2 currently stands at around 50 million tonnes. The primary method of production of H2 is steam reforming which...

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