Engineering Commons^™

Rational Design Of Highly Efficient Electrocatalysts Using Atomic Layer Deposition: From Nanoparticle To Single Atom, Junjie Li

Electronic Thesis and Dissertation Repository

Polymer electrolyte membrane fuel cells (PEMFCs) have been attracted significant attention due to their high energy efficiency. The electrocatalyst is one of the most important parts. However, state-of-the-art electrocatalysts suffer from several challenges, including 1) low stability under harsh working conditions; 2) low atomic utilization efficiency, especially for noble metals. This thesis, therefore, focuses on the design of highly efficient and stable electrocatalysts from nanoparticles down to single atoms using atomic layer deposition (ALD) and further understand the insight mechanisms.

Firstly, Pt nanoparticles are selectively deposited on the TiO₂ modified N-doped carbon nanotubes. The strong metal-support interactions between Pt …

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 …

Kinetic Monte Carlo Investigations Involving Atomic Layer Deposition Of Metal-Oxide Thinfilms, David Tyler Magness

MSU Graduate Theses

Atomic Layer Deposition is a method of manufacturing thin film materials. Metal-oxides such as zinc-oxide and aluminum-oxide are particularly interesting candidates for use in microelectronic devices such as tunnel junction barriers, transistors, Schottky diodes, and more. By adopting a 3D Kinetic Monte Carlo model capable of simulating ZnO deposition, the effect of parameters including deposition temperature, chamber pressure, and composition of the initial substrate at the beginning of deposition can be investigated. This code generates two random numbers: One is used to select a chemical reaction to occur from a list of all possible reactions and the second is used …

Strategies For The Stabilization Of Metal Anodes For Li And Na Metal Batteries, Yang Zhao

Electronic Thesis and Dissertation Repository

Li-metal batteries (LMBs) and Na-metal batteries (NMBs) are considered as the promising candidates to replace the conventional Li-ion batteries (LIBs) due to their high theoretical energy density. For LMBs and NMBs, Li metal and Na metal are the ultimate choices to achieve their high energy density due to the high specific capacity, low electrochemical potential and lightweight. However, as alkali metals, both Li and Na metal anodes suffer from serious challenges including 1) Li/Na dendrite formations and short circuits; 2) Low Coulombic efficiency (CE) and poor cycling performance; and 3) Infinite volume changes. This thesis mainly focuses on the design …

Development Of Nanomaterials For Lithium-Ion Batteries By Atomic Layer Deposition, Biqiong Wang

Electronic Thesis and Dissertation Repository

Lithium ion batteries (LIBs) have been the dominant candidate in the field of energy storage. The ever-growing demand of high energy and power density, longer battery life, and more assured safety level has geared the development of LIBs towards all-solid-state batteries (ASSBs). The solid-state nature allows more flexibility in battery design and higher area capacity to be obtained within limited space. Moreover, replacing liquid electrolytes with solid-state electrolytes (SSEs) is a most effective approach to achieve safer battery system. In addition, ASSBs hold great promise in the actual fabrication of microbatteries for microelectronics. Therefore, a technique which can synthesize materials …

Development Of Novel Nanomaterials For Lithium Sulfur Batteries, Xia Li

Electronic Thesis and Dissertation Repository

Lithium-sulfur batteries are considered as the most promising next generation high-energy batteries. Compared with other kinds of battery, Li-S batteries have ultra-high theoretical energy density, which is a good candidate for electric vehicles and hybrid electric vehicles in future. However, there are still many challenges to be addressed in Li-S batteries. Design of electrodes, selection of electrolytes, and battery assemble have direct effects on the safety, cost and electrochemical performance of Li-S batteries. Therefore, it is greatly important to develop novel electrodes to achieve high-energy for Li-S batteries. This thesis mainly focuses on the design of sulfur cathode of Li-S …

Development Of Low-Temperature Atomic Layer Deposition Of Ultra-Thin Ruco Direct Plate Liners For Flexible Electronics Applications, Dillon Alexander Gregory

Legacy Theses & Dissertations (2009 - 2024)

Low temperature plasma-assisted atomic layer deposition-grown metal nanocomposite layers based on mixtures of ruthenium and cobalt have been investigated as potential copper adhesion/barrier layers in flexible electronics applications. The success of adapting this process to flexible electronics depends on the candidate barriers meeting several necessary properties including sufficient electrical conductivity, compatibility with Cu electroplating, and ability to prevent Cu diffusion into the substrate. Preliminary testing has shown that atomic layer deposition (ALD) can be used as a technique for depositing alloyed metallic barrier layers at the lower thermal constraints dictated by the use of polymer substrates and still produce continuous …

Strong Metal Support Interaction Of Pt On Tio₂ Grown By Atomic Layer Deposition And Physical Vapor Deposition For Fuel Cell Applications, Robin Paul Hansen

Legacy Theses & Dissertations (2009 - 2024)

Several roadblocks prevent the large-scale commercialization of hydrogen fuel cells, including the stability of the Pt catalysts and their substrates, as well as the high cost of Pt. This is particularly true for the cathode, which requires a higher Pt loading because of the slow kinetics of the oxygen reduction reaction (ORR). The problem with the stability of the substrate can be solved by replacing the traditional carbon support with a conductive metal oxide such as reduced TiO2, which will not easily corrode and should result in longer lasting fuel cells. In this study, Pt was deposited either by atomic …

Doping Plasmon-Enhanced Tio2 With Zirconia To Improve Solar Energy Harvesting In Dye-Sensitized Solar Cells, Anastasia Pasche

Electronic Thesis and Dissertation Repository

Solar energy is a promising solution towards meeting the world’s ever-growing energy demand. Dye-sensitized solar cells (DSSCs) are hybrid organic-inorganic solar cells with potential for commercial application, but are plagued by inefficiency due to their poor sunlight absorption. Silver nanoparticles have been shown to enhance the absorptive properties of DSSCs, but their plasmonic resonance causes local hot spots, resulting in cell deterioration. This thesis studies the mitigation of thermal energy loss of plasmon-enhanced DSSCs by the co-incorporation of zirconia, a well-known thermostabilizer, into the cell’s photoactive material. TiO2 was also synthesized using green bio-sourced solvents in supercritical CO2 to compare …

Development Of Advanced Nanomaterials For Potential Lithium-Ion Battery Application, Jian Liu

Electronic Thesis and Dissertation Repository

Lithium-ion batteries (LIBs) are promising energy storage media under serious consideration for practical applications in electric vehicle (EVs) and hybrid electric vehicles (HEVs). However, to meet the requirements for EVs and HEVs, the performance of commercially available LIBs needs to be greatly improved in terms of the energy density, cycling life, rate capability, safety and cost. It is well known that the LIB performance is highly dependent on the choice of electrode materials. Therefore, it is greatly important to develop new electrode materials as replacements for graphite/LiCoO₂ used in commercial LIBs, in order to achieve high-performance LIBs desirable for …

On Developing Novel Energy-Relates Nanostructured Materials By Atomic Layer Deposition, Xiangbo Meng

Electronic Thesis and Dissertation Repository

ABSTRACT

This thesis presents the fabrication of a series of novel nanostructured materials using atomic layer deposition (ALD). In contrast to traditional methods including chemical vapor deposition (CVD), physical vapor deposition (PVD), and solution-based processes, ALD benefits the synthesis processes of nanostructures with many unrivalled advantages such as atomic-scale control, low temperature, excellent uniformity and conformality. Depending on the employed precursors, substrates, and temperatures, the ALD processes exhibited different characteristics. In particular, ALD has capabilities in fine-tuning compositions and structural phases. In return, the synthesis and the resultant nanostructured materials show many novelties.

This thesis covers ALD processes of four …

Synthesis Of Ald Zinc Oxide And Thin Film Materials Optimization For Uv Photodetector Applications, Kandabara Nouhoum Tapily

Electrical & Computer Engineering Theses & Dissertations

Zinc oxide (ZnO) is a direct, wide bandgap semiconductor material. It is thermodynamically stable in the wurtzite structure at ambient temperature conditions. ZnO has very interesting optical and electrical properties and is a suitable candidate for numerous optoelectronic applications such as solar cells, LEDs and UV-photodetectors. ZnO is a naturally n-type semiconductor. Due to the lack of reproducible p-type ZnO, achieving good homojunction ZnO-based photodiodes such as UV-photodetectors remains a challenge. Meanwhile, heterojunction structures of ZnO with p-type substrates such as SiC, GaN, NiO, AlGaN, Si etc. are used; however, those heterojunction diodes suffer from low efficiencies. ZnO is an …