Engineering Commons^™

Electrical Properties Of Metal/Wse2structures, Zeel Rajiv Gandhi

Theses

The formation of low resistance metal contacts on two-Dimensional layer (2-D) of WSe2 is a big challenge. In this research, a comparative study is presented on the electrical properties of metal/WSe2 Schottky barrier diodes with various metals such as Au, In, Al, and Ga in the temperature range of 80K to 400K well within the domain of thermionic emission theory.

Topics covered here include the factors that determine the Schottky barrier height, the device capacitance, and its current-voltage (I-V) characteristics. I-V curves for different metals on WSe2 are analyzed as function of temperature. Barrier height is determined from Au-nWSe2 Schottky …

Formulation Of Uv Curable Resins Utilized In Vat Photo Polymerization For The Additive Manufacturing Of Gun Propulsion Charge In 3d Printers, David T. Bird

Theses

Formulating resins for Additive Manufacturing (AM), utilizing UV laser stereolithography, is a new technique that makes it possible for the fabrication of complex geometries with high dimensional resolution. This layer by layer photopolymerization approach spans various industrial sectors from adhesives, inks and optical fibers to nanotechnology and biomaterials. UV curable resins such as epoxides, vinyl ethers and other acrylates are important monomers that offer effective mediums for energetic materials, and the potential exists to develop environmentally friendly formulations with suspended energetic materials at various solids loading levels.

Developing techniques for UV curing formulations of highly loaded energetic suspensions is a …

Optimization Of The Front End Of Cdte Solar Cells, Yunfei Chen

Dissertations

The front end of CdTe solar cells consists of two layers: a transparent conducting oxide (TCO) layer and a window layer. New wider band gap materials, ZnMgO are being used to replace CdS as the window layer for the purpose of removing blue loss. For ZnMgO, three important parameters, including the atomic Mg content (x), thickness (t), and doping concentration (n) can play important roles on the performance of CdTe solar cells. In this dissertation, systematic simulation, by solar cell capacitance simulator (SCAPS), and experiments are used to investigate the influences of these …

Numerical Simulation For Identification Of Insects Using A Cw Lidar System, Christo Videlov

Theses

Mosquitos are the most common vector of disease in the world, causing millions of deaths a year. While curing the diseases they cause is one approach to this problem, another could be to avoid the mosquitos in the first place. Knowing their flight patterns, location, and population in one area could aid in this. Additionally, classifying the mosquitos in an area would be helpful. The age and sex of the mosquito is important to find as they affect the chances of the insect carrying diseases such as malaria or yellow fever.

Many current methodologies to monitor insects are based on …

Smart Polymeric Temperature Sensors – For Biological Systems, Greenee Anilkumar Sinha

Theses

The damaged brain is vulnerable to increase in brain temperature after a severe head injury. Continuous monitoring of intracranial temperature depicts functionality essential to the treatment of brain injury Many innovations have been made in the biomedical industry relying on electronic implants in treating condition such as traumatic brain injury (TBI) or other cerebral diseases. Hence, a methodical and reliable way to measure the temperature is crucial to assess the patient’s situation. In this investigation, an analysis of various approaches to detect the change in the temperature due to resistance, current-voltage characteristics with respect to time has been evaluated. Also, …

Memorizing Chromic Response To Pressure, Maulik Kiritkumar Padh

Theses

Almost all appliances are prone to mechanical stress in one form or the other. An increasing dependence on machines in daily life calls for a need to increase their maintenance quality. Various materials, methods and configurations to observe mechanical pressure have been devised and this paper discusses one such technique. The use of gold nanoparticles in its one dimensional array causes plasmonic coupling between the nanoparticles, which when disrupted creates a plasmonic shift in its assembly. Such a film, when casted on a polymer with a known elastic limit, causes deformation by an application of stress. This forces the film …

Corrosion Studies Of Stainless Steel Blades, Dhruv S. Kothari

Theses

Corrosion is a subject of interest to interdisciplinary research communities that includes fields of materials science, chemistry, physics, metallurgy and chemical engineering. In order to understand the mechanisms of corrosion and the function of corrosion inhibitors, the reactions at the interfaces between the corrosive electrolyte and a steel surface, particularly at the initial stages of the corrosion process, need to be described. Naturally, these reactions are strongly affected by the nature and properties of the steel surfaces. It is however seen that the majority of recent corrosion and corrosion-inhibition investigations are limited to electrochemical testing, with ex situ analysis of …

Development Of Low Alloy Steel By Direct Metal Laser Sintering, Elias Jelis

Dissertations

The US Department of Defense is interested in developing, understanding, and optimizing process parameters for low alloy (4340/4140 steel) for the powder bed fusion process. Low alloy steel is used in parts where high strength and toughness are required. During parameter optimization, several aspects of the process are investigated. Powder size and morphology optimization is important for manufacturability because adequate packing is required to produce full density components. Microstructure evaluation is used in order to provide insight into parameters that lead to optimal mechanical performance and recoating performance. Influence of residual stress is evaluated with this process. Large thermal stress …

Electrical, Electronic And Optical Properties Of Mos2 & Ws2, Weitao Tang

Theses

Two dimensional materials such as graphene, boron nitride and transition metal dichalcogenide (TMDCs) monolayers have arisen as a new class of materials with unique properties at monolayer thickness. Their electrical, electronic and optical properties are of great importance for a variety of applications in optoelectronics as light emitters, detectors, and photovoltaic devices. This work focuses on MoS₂ and WS₂, which are two important members of the TMDC class of materials. The properties of monolayer MoS₂ and WS₂ are investigated as well as the properties of bulk MoS₂ and WS₂ to provide an understanding …

Heat Transfer In Silicon - Experiments And Simulation, Chihlin Huang

Theses

The purpose of this thesis is to study the heat transfer in silicon. Silicon is the key semiconductor material, and thermal processing is the traditional method that is used in semiconductor processing. In this research, we can predict the temperature of the silicon wafer during heating. This ability to predict wafer temperature during semiconductor processing will facilitate in the following: (a) Process temperature uniformity, (b) Film thickness uniformity, (c) Diffusion, (d) Process yield, (e) Thermally induced stresses, and (f) Device yield - spatially and temporally across the wafer. For low temperature applications, IC chips can be modeled to simulate the …

Electrical, Electronic And Optical Properties Of Mose2 And Wse2, Sushant Shashikant Rassay

Theses

Transition-metal dichalcogenides (TMDC) crystals have emerged as a new class of semiconductors that display distinctive properties at monolayer thickness. Their electrical, electronic and optical properties are of particular interest and importance for applications in optoelectronics as light emitters, detectors, and photovoltaic devices. Monolayer MoSe₂ and WSe₂ have an intrinsic band-gap in the visible region of the solar spectrum (400nm - 700nm) which makes them distinct from other 2-D materials like graphene.

In this study, the electrical, electronic and optical properties of monolayer and bulk MoSe₂ and WSe₂ are studied. The electronic band structures are presented for …