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Full-Text Articles in Engineering
Design And Fabrication Of A Microstrip Bandpass Filter In Ltcc, Allison Rucker
Design And Fabrication Of A Microstrip Bandpass Filter In Ltcc, Allison Rucker
Electrical Engineering Undergraduate Honors Theses
The goal of the project was to design and fabricate a bandpass filter with a center frequency of 25GHz with a 2GHz bandwidth. The first step was to do the calculation to design a bandpass filter to meet these specifications along with the properties of the DupontTM GreenTapeTM 9K7. HFSS was then used to verify the results from the initial calculations. There was a significant error between the two results, so more tweaking was done to the calculations to get a better center frequency. After a final design was decided, the fabrication process started. Low-Temperature Co-Fired Ceramics (LLTC) …
Compositionally Graded Indium Gallium Nitride Solar Cells, Christopher Matthews
Compositionally Graded Indium Gallium Nitride Solar Cells, Christopher Matthews
Electrical Engineering Undergraduate Honors Theses
For the past several decades, methods to harvest solar energy have been investigated intensively. A majority of the work done in this field has been on solar cells made with silicon – the most mature semiconductor material. Recent developments in material fabrication and processing techniques have enabled other semiconductor materials to attract practical interest and research effort as well. Indium gallium nitride (InGaN) is one such material. The material properties of InGaN indicate that solar cells made with it have the potential to achieve much higher power density than a standard silicon solar cell. High power density InGaN solar cells …
Resonant Spectra Of Metal Nanotoroids Of Various Sizes, Huong Quynh Tran
Resonant Spectra Of Metal Nanotoroids Of Various Sizes, Huong Quynh Tran
Electrical Engineering Undergraduate Honors Theses
Nowadays, the manipulation of light by using metallic nanostructures has wide applications in photonics, optoelectronics and energy conversion. Along with other universities all over the world, the University of Arkansas is researching on nano-antennas’ design, fabrication and applications. Current research in Dr. El-Shenawee’s Terahertz Imaging and Spectroscopy Computational Electromagnetics Group, has computationally investigated the behaviors of plasmonic nanostructures by using the commercial finite element electromagnetic solver Ansys® HFSS. This work reproduced the previous work of spectral absorption enhancement of infinite and finite arrays of silver and gold nanotoroids with sizes of the inner radii: 13nm – 21nm, while outer radius …
Comparison Of Low-Temperature Co-Fired Ceramic And Direct Bonded Copper For Single Ended Primary Inductance Topology, Kristopher Cody Johnson
Comparison Of Low-Temperature Co-Fired Ceramic And Direct Bonded Copper For Single Ended Primary Inductance Topology, Kristopher Cody Johnson
Electrical Engineering Undergraduate Honors Theses
This work examines the thermal dissipation characteristics of Low-Temperature Co-fired Ceramic (LTCC) and Direct Bonded Copper (DBC) with the implementation of a Single Ended Primary Inductance Converter (SEPIC) topology. The advantages and disadvantages of the two substrates will be explored in addition to a description of the design and control of the SEPIC. It will be shown that the DBC implementation is superior with regards to thermal dissipation, but that LTCC has advantages in high- density packaging, RF applications, and embedded components. These substrates and converters provide many advantages in industrial applications that include automotive and grid level implementations. Additional …
The Synthesis And Characterization Of Copper Indium Sulfide And Cadmium Selenide Nanocrystals And Their Applications In Photodetectors, Zachary T. Bever
The Synthesis And Characterization Of Copper Indium Sulfide And Cadmium Selenide Nanocrystals And Their Applications In Photodetectors, Zachary T. Bever
Electrical Engineering Undergraduate Honors Theses
Semiconductor nanocrystals are a topic of much interest in electrical engineering. Their use has been explored for many applications. This paper investigates the synthesis and characterization of CuInS2 and CdSe nanocrystals. As the nanocrystals were left in reaction for increasing amounts of time, the bandgap of the material decreased as the nanocrystal size increased due to the quantum confinement effect. The CdSe nanocrystals were then investigated in a photodetector application which achieved a detectivity on the order of 10^9 cmHz^(1/2)W^(-1).
A Comparison Of Pressure-Less Silver Sintering Materials With Conventional Electronic Die Attach Practices, Ross M. Liederbach
A Comparison Of Pressure-Less Silver Sintering Materials With Conventional Electronic Die Attach Practices, Ross M. Liederbach
Electrical Engineering Undergraduate Honors Theses
This thesis contains information on an experiment which validates silver sintering paste manufacturer’s die attach processes and examines feasibility for use in commercial products. Four silver pastes were used in constructing die attach samples, which were then void and shear tested. The silver sintering materials that are investigated in this work are compared with manufacturer data and also with data from conventional attaches such as conductive epoxy and solder. In addition, materials demonstrating the highest shear strength were down-selected and processed to compare thermal characteristics with solder and conductive epoxy. Under theoretical analysis, the characteristics of silver provide the most …
Plasmonic Effect On The Photoluminescence Of Inas Quantum Dot Nanostructures, David Fryauf
Plasmonic Effect On The Photoluminescence Of Inas Quantum Dot Nanostructures, David Fryauf
Electrical Engineering Undergraduate Honors Theses
New materials for thin film photovoltaic applications are being explored worldwide, and one of the most popular new implementations is the introduction of an intermediate band gap in the semiconductor energy structure. Careful manipulation of semiconductor lattice material can form nanostructures such as quantum dots, which can be tuned to control specific intermediate energy levels. The introduction of an intermediate band in photovoltaic devices has a theoretical potential sunlight-toelectricity efficiency of roughly 63%. However, a specific material challenge of these thin film devices is limited absorption of long wavelengths of light. To increase absorption of the sun's visible spectrum, plasmonic …
Optical Properties Of Colloidal Core/Shell Nanocrystals, Abhishek Joshi
Optical Properties Of Colloidal Core/Shell Nanocrystals, Abhishek Joshi
Electrical Engineering Undergraduate Honors Theses
Recently, colloidal core/shell nanocrystals have found use in several applications such as solar cells, light emitting diodes, fluorescent dies, etc. In this thesis, optical properties of colloidal CdSe/ZnS core/shell nanocrystals were studied. The samples were prepared such that the nanocrystals were embedded in a UV curable resin. Once the samples were cured, they were placed in different spectrophotometers to measure the absorbance and the photoluminescence (PL) spectrum. The effect on the absorbance and PL spectra was investigated by using nanocrystal samples of different quantum dot sizes and by changing the temperature of the samples. It was found that the energy …