subject:(Zinc oxide)

University of Waterloo

1. Ismayilov, Vugar. Perovskite Oxide Combined With Nitrogen-Doped Carbon Nanotubes As Bifunctional Catalyst for Rechargeable Zinc-Air Batteries.

Degree: 2014, University of Waterloo

URL: http://hdl.handle.net/10012/8369

► Zinc air batteries are among the most promising energy storage devices due to their high energy density, low cost and environmental friendliness. The low mass… (more)

▼ Zinc air batteries are among the most promising energy storage devices due to their high energy density, low cost and environmental friendliness. The low mass and cost of zinc air batteries is a result of traditional active materials replacement with a thin gas diffusion layer which allows the battery to use the oxygen directly from the air. Despite the environmental and electronic advantages offered by this system, challenges related to drying the electrolyte and catalyst, determining a high activity bifictional catalyst, and ensuring durability of the gas diffusion layer need to be optimized during the fabrication of rechargeable zinc-air batteries. To date, platinum on carbon (Pt/C) provides the best electrochemical catalytic activity in acidic and alkaline electrolytes. However, the difficult acquisition and high cost of this catalyst mandates investigation into a new composition or synthesis of a bifunctional catalyst. A number of non-precious metal catalyst have been introduced for zinc-air batteries. Nevertheless, their catalytic activities and durability are still too low for commercial rechargeable zinc-air batteries. Thus, it is very important to synthesize a highly active bifunctional catalyst with good durability for long term charge and discharge use. In this study, it is proposed that a manganese-based perovskite oxide nanoparticle combined with nitrogen doped carbon nanotubes willshow promising electrochemical activity with remarkable cycle stability as a bifunctional catalyst for zinc-air batteries. In the first part of this work, nano-sized LaMnO3 and LaMn0.9Co0.1O3 were prepared to research the effectiveness of Co doping into LaMnO3 and its effect on electrochemical catalytic activities. To prepare LaMnO3 and LaMn0.9Co0.1O3, a hydrothermal reaction method was applied to synthesize nanoparticles which can increase the activity of perovskite type oxides. The result shows that while perovskite oxides replacing 10 wt. % of Mn doped with Co metal did not iv change its crystalline structure, the oxygen evolution reaction (OER) performance was increased by 600%. In the second part, a core-corona structured bifunctional catalyst (CCBC) was synthesized by combining LaMn0.9Co0.1O3 nanoparticles with nitrogen doped carbon nanotubes (NCNT). NCNT was chosen because of its large surface area and high catalytic activity for ORR. SEM and TEM analysis show that metal oxide nanoparticles were surrounded with nanotubes. Based on the electrochemical performances, ORR and OER activity is attributed to NCNT and the metal oxide core, respectively, complementing the activities of each other. Furthermore, its unique morphology introduces synergetic activity especially for OER. Electrochemical test results show that the onset potential was enhanced from -0.2 V (in LaMnO3 and LaMn0.9Co0.1O3) to -0.09 V (in CCBC) and the half wave potential was improved from -0.38 V to -0.19 V. In the third part, a single cell zinc-air battery test was performed using CCBC as the bifunctional catalyst for the air electrode. These results…

Subjects/Keywords: bifunctional catalyst; Zinc-air battery; perovskite oxide

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APA (6^th Edition):

Ismayilov, V. (2014). Perovskite Oxide Combined With Nitrogen-Doped Carbon Nanotubes As Bifunctional Catalyst for Rechargeable Zinc-Air Batteries. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/8369

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Ismayilov, Vugar. “Perovskite Oxide Combined With Nitrogen-Doped Carbon Nanotubes As Bifunctional Catalyst for Rechargeable Zinc-Air Batteries.” 2014. Thesis, University of Waterloo. Accessed December 08, 2019. http://hdl.handle.net/10012/8369.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Ismayilov, Vugar. “Perovskite Oxide Combined With Nitrogen-Doped Carbon Nanotubes As Bifunctional Catalyst for Rechargeable Zinc-Air Batteries.” 2014. Web. 08 Dec 2019.

Vancouver:

Ismayilov V. Perovskite Oxide Combined With Nitrogen-Doped Carbon Nanotubes As Bifunctional Catalyst for Rechargeable Zinc-Air Batteries. [Internet] [Thesis]. University of Waterloo; 2014. [cited 2019 Dec 08]. Available from: http://hdl.handle.net/10012/8369.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ismayilov V. Perovskite Oxide Combined With Nitrogen-Doped Carbon Nanotubes As Bifunctional Catalyst for Rechargeable Zinc-Air Batteries. [Thesis]. University of Waterloo; 2014. Available from: http://hdl.handle.net/10012/8369

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Waterloo

2. Zhang, Jing. Electrolyte Design and Engineering for Electrochemical Energy System.

Degree: 2019, University of Waterloo

URL: http://hdl.handle.net/10012/14559

► Electrochemical energy conversion and storage technology is considered as a promising replacement of fossil fuels to directly convert the chemical energy to electrical energy through… (more)

▼ Electrochemical energy conversion and storage technology is considered as a promising replacement of fossil fuels to directly convert the chemical energy to electrical energy through electrochemical reactions, which has environmental-benign emissions and excellent operational efficiencies. As key components of an electrochemical device, both electrode and electrolyte will have substantial effects on the performance of an electrochemical energy conversion and storage system. While there have been many research and development concerning electrode materials, the investigations focusing on electrolyte are rather limited. It is worth noticing that the design and preparation of an ideal electrolyte is very necessary, as it plays a critical role in establishing important properties of an electrochemical energy conversion and storage system including internal resistance, thermal stability, power density, energy density, cycle life, and so on. In this thesis, electrolytes are divided into two types by physical properties, which are liquid electrolyte and solid-state electrolyte. Liquid electrolyte can be further grouped into aqueous and non-aqueous ones based on different solvent utilization, while solid electrolyte can be further separated into all-solid-state and quasi-solid-state electrolytes. Overall, the development of electrolytes is moving from liquid towards solid electrolytes with the rapid growing demand of flexible, foldable, portable, micro and wearable electrochemical devices. In this work, a novel strategy towards hybrid aqueous electrolyte was firstly put forward for an all-aqueous redox flow battery with unprecedented high energy density.Theoretically, the electrolyte acidic/basic properties have a great influence on redox pair potential. By tuning the pH of electrolyte, the battery voltage can be effectively enhanced, finally leading to an increase in energy density. Inspired by this concept, an all-aqueous hybrid alkaline zinc/iodine flow battery is designed and demonstrated with a 0.47 V battery potential enhancement compared to the conventional counterpart. Also, a high-energy-density of 330.5 Wh L-1 was achieved for this all-aqueous hybrid alkaline zinc/iodine flow battery. It is an unprecedented record for an all-aqueous redox flow battery obtained to date, which is even 1.6 times of the highest reported energy density value. Overall, this hybrid alkaline zinc/iodine system demonstrates a new design with promising performance for an all-aqueous redox flow battery, and more importantly, opens a feasible and effective approach for achieving high-voltage high-energy-density all-aqueous electrochemical energy device. After that, I present a functionalized nanocellulose-based membrane with a laminated structure to be used as a hydroxide-conducting solid-state electrolyte. The introduced functional groups in the nanocellulose significantly boost the hydroxide conductivity (e.g., 58.8 mS cm-1 at 70 °C) due to the enhanced ion-exchange capacity and the increased amorphousness of the…

Subjects/Keywords: redox flow battery; zinc air battery; electrochemical gas sensor; hybrid electrolyte; graphene oxide; cellulose

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Zhang, J. (2019). Electrolyte Design and Engineering for Electrochemical Energy System. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/14559

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Zhang, Jing. “Electrolyte Design and Engineering for Electrochemical Energy System.” 2019. Thesis, University of Waterloo. Accessed December 08, 2019. http://hdl.handle.net/10012/14559.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Zhang, Jing. “Electrolyte Design and Engineering for Electrochemical Energy System.” 2019. Web. 08 Dec 2019.

Vancouver:

Zhang J. Electrolyte Design and Engineering for Electrochemical Energy System. [Internet] [Thesis]. University of Waterloo; 2019. [cited 2019 Dec 08]. Available from: http://hdl.handle.net/10012/14559.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Zhang J. Electrolyte Design and Engineering for Electrochemical Energy System. [Thesis]. University of Waterloo; 2019. Available from: http://hdl.handle.net/10012/14559

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Waterloo

3. Chiu, Wan Hang Melanie. Förster Resonance Energy Transfer Mediated White-Light-Emitting Rhodamine Fluorophore Derivatives-Gamma Phase Gallium Oxide Nanostructures.

Degree: 2012, University of Waterloo

URL: http://hdl.handle.net/10012/7036

► The global lighting source energy consumption accounts for about 22% of the total electricity generated. New high-efficiency solid-state light sources are needed to reduce the… (more)

▼ The global lighting source energy consumption accounts for about 22% of the total electricity generated. New high-efficiency solid-state light sources are needed to reduce the ever increasing demand for energy. Single-phased emitter-based composed of transparent conducting oxides (TCOs) nanocrystals and fluorescent dyes can potentially revolutionize the typical composition of phosphors, the processing technology founded on the binding of dye acceptors on the surface of nanocrystals, and the configurations of the light-emitting diodes (LEDs) and electroluminescence devices. The hybrid white-light-emitting nanomaterial is based on the expanded spectral range of the donor-acceptor pair (DAP) emission originated from the γ-gallium oxide nanocrystals via Förster resonance energy transfer (FRET) to the surface-anchored fluorescent dyes. The emission of the nanocrystals and the sensitized emission of the chromophore act in sync as an internal relaxation upon the excitation of the γ–gallium oxide nanocrystals. It extends the lifetime of the secondary fluorescent dye chromophore and the internal relaxation within this hybrid complex act as a sign for a quasi single chromophore. The model system of white-light-emitting nanostructure system developed based on this technology is the γ–gallium oxide nanocrystals-Rhodamine B lactone (RBL) hybrid complex. The sufficient energy transfer efficiency of 31.51% within this system allowed for the generation of white-light emission with the CIE coordinates of (0.3328, 0.3380) at 5483 K. The relative electronic energy differences of the individual components within the hybrid systems based on theoretical computation suggested that the luminance of the nanocomposite comprised of RBL is dominantly mediated by FRET. The production of white-light-emitting diode (WLED) based on this technology have been demonstrated by solution deposition of the hybrid nanomaterials to the commercially available ultraviolet (UV) LED due to the versatility and chemical compatibility of the developed phosphors.

Subjects/Keywords: White-light-emitting; Light emitting diode; Transparent conducting oxides; Nanoparticles; Quasi single hybrid chromophore; Nanolite; Gamma-phase gallium oxide; Gallium oxide; Zinc oxide; Rhodamine Fluorophore; Förster resonance energy transfer

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APA (6^th Edition):

Chiu, W. H. M. (2012). Förster Resonance Energy Transfer Mediated White-Light-Emitting Rhodamine Fluorophore Derivatives-Gamma Phase Gallium Oxide Nanostructures. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/7036

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Chiu, Wan Hang Melanie. “Förster Resonance Energy Transfer Mediated White-Light-Emitting Rhodamine Fluorophore Derivatives-Gamma Phase Gallium Oxide Nanostructures.” 2012. Thesis, University of Waterloo. Accessed December 08, 2019. http://hdl.handle.net/10012/7036.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Chiu, Wan Hang Melanie. “Förster Resonance Energy Transfer Mediated White-Light-Emitting Rhodamine Fluorophore Derivatives-Gamma Phase Gallium Oxide Nanostructures.” 2012. Web. 08 Dec 2019.

Vancouver:

Chiu WHM. Förster Resonance Energy Transfer Mediated White-Light-Emitting Rhodamine Fluorophore Derivatives-Gamma Phase Gallium Oxide Nanostructures. [Internet] [Thesis]. University of Waterloo; 2012. [cited 2019 Dec 08]. Available from: http://hdl.handle.net/10012/7036.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Chiu WHM. Förster Resonance Energy Transfer Mediated White-Light-Emitting Rhodamine Fluorophore Derivatives-Gamma Phase Gallium Oxide Nanostructures. [Thesis]. University of Waterloo; 2012. Available from: http://hdl.handle.net/10012/7036

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

4. Stewart, Katherine Mariann Elizabeth. Design of Polymeric Sensing Materials for Volatile Organic Compounds: Optimized Material Selection for Ethanol with Mechanistic Explanations.

Degree: 2016, University of Waterloo

URL: http://hdl.handle.net/10012/11092

► There are many applications in which sensing and monitoring volatile organic compounds (VOCs) and other gas analytes are important. This thesis focusses on finding suitable… (more)

▼ There are many applications in which sensing and monitoring volatile organic compounds (VOCs) and other gas analytes are important. This thesis focusses on finding suitable sensing materials for ethanol to reduce the instances of people driving while intoxicated. To find suitable sensing materials, many constraints must be taken into consideration. For example, a sensing material and sensor must have the appropriate sensitivity and selectivity required. The goal is to create a sensing material or multiple materials capable of detecting ethanol that is emitted from the skin (transdermally). This requires highly sensitive sensing materials and sensors capable of detecting ethanol close to 5 ppm. This limit of 5 ppm was confirmed by measuring transdermal ethanol. In addition, to avoid false positives, the sensor must be able to selectively identify ethanol (i.e. respond preferentially to ethanol). To achieve this goal, polymeric sensing materials were used because of their ability to be tailored towards a target analyte. Multiple polymeric sensing materials were designed, synthesized, and evaluated as a sensing material for ethanol. Both the sensitivity and selectivity of the sensing materials were evaluated using a specially designed experimental test set-up that included a highly sensitive gas chromatograph (GC) capable of detecting down to the ppb range. In total, over thirty potential sensing materials were evaluated for ethanol. These sensing materials, which include polyaniline (PANI) and two of its derivatives, poly (o-anisidine) (PoANI) and poly (2,5-dimethyl aniline) (P25DMA), doped with various concentrations of five different metal oxide nanoparticles (Al2O3, CuO, NiO, TiO2, and ZnO), were synthesized and evaluated for sensitivity and selectivity to ethanol. In addition, specialized siloxane-based polymers and other polymers such as poly (methyl methacrylate) (PMMA) and polypyrrole (PPy) were evaluated. From these thirty plus sensing materials, P25DMA doped with TiO2, NiO, and Al2O3, along with PPy, had the best sensitivity towards ethanol. Most of the materials tested, with the exception of the CuO doped P25DMA, P25DMA doped with 20% ZnO, poly (ethylene imine) (PEI), and the siloxane-based sensing materials, were able to sorb, and therefore detect, 5 ppm of ethanol. Therefore, the sensitivity requirement of 5 ppm was satisfied. In terms of selectivity, P25DMA doped with 5% Al2O3 and P25DMA doped with 10% TiO2 had the best selectivity towards ethanol with respect to five typical interferent gases (acetaldehyde, acetone, benzene, formaldehyde, and methanol). Some of the most promising polymeric sensing materials were then deposited onto two different kinds of sensors: a capacitive radio frequency identification (RFID) sensor and a mass-based microcantilever microelectromechanical systems (MEMS) sensor. These sensors were evaluated for sensitivity, selectivity, and response and recovery times. It was found that P25DMA doped with 20% NiO had a detection limit of 3 ppm on the RFID sensor, whereas…

Subjects/Keywords: Gas Sensor; Ethanol Sensor; Sensing Mechanisms; Volatile Organic Compound (VOC); Polyaniline; Poly (2,5-dimethyl aniline); Poly (o-anisidine); aluminum oxide (Al2O3); copper oxide (CuO); Nickel oxide (NiO); Titanium oxide (TiO2); Zinc oxide (ZnO); Dopants; Sensing Materials

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Stewart, K. M. E. (2016). Design of Polymeric Sensing Materials for Volatile Organic Compounds: Optimized Material Selection for Ethanol with Mechanistic Explanations. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/11092

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Stewart, Katherine Mariann Elizabeth. “Design of Polymeric Sensing Materials for Volatile Organic Compounds: Optimized Material Selection for Ethanol with Mechanistic Explanations.” 2016. Thesis, University of Waterloo. Accessed December 08, 2019. http://hdl.handle.net/10012/11092.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Stewart, Katherine Mariann Elizabeth. “Design of Polymeric Sensing Materials for Volatile Organic Compounds: Optimized Material Selection for Ethanol with Mechanistic Explanations.” 2016. Web. 08 Dec 2019.

Vancouver:

Stewart KME. Design of Polymeric Sensing Materials for Volatile Organic Compounds: Optimized Material Selection for Ethanol with Mechanistic Explanations. [Internet] [Thesis]. University of Waterloo; 2016. [cited 2019 Dec 08]. Available from: http://hdl.handle.net/10012/11092.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Stewart KME. Design of Polymeric Sensing Materials for Volatile Organic Compounds: Optimized Material Selection for Ethanol with Mechanistic Explanations. [Thesis]. University of Waterloo; 2016. Available from: http://hdl.handle.net/10012/11092

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Waterloo

5. Janfeshan, Bita. Development of Zinc Oxide Nanowires and Quantum Dot Incorporation for Photovoltaic Applications.

Degree: 2016, University of Waterloo

URL: http://hdl.handle.net/10012/10144

► Heterojunctions of metal oxide semiconductors with quantum dots (QD) have been deployed in a number of advanced electronic devices. Improvement in the devices’ performance requires… (more)

▼ Heterojunctions of metal oxide semiconductors with quantum dots (QD) have been deployed in a number of advanced electronic devices. Improvement in the devices’ performance requires in-depth studies on charge carrier transfer dynamics. In this work, charge carrier dynamics, at the interface on zinc oxide nanowires (ZnO NW) with cadmium selenide QDs, were investigated. ZnO NWs were synthesized and characterized through the chemical vapor deposition (CVD) and hydrothermal methods. Both methods yielded highly crystalline ZnO structures. The hydrothermally grown NWs were doped with aluminum (Al) and the spectroscopy analyses showed that Al was successfully incorporated into the ZnO crystalline structure. Colloidal cadmium selenide/zinc sulfide (CdSe/ZnS) core/shell QDs were incorporated into synthesized ZnO NW arrays. The interaction and wettability of two different QD ligands (Octadecylamine and oleic acid) on the self-assembly of QDs in the NW spacing were investigated using electron microscopy. Afterwards, the charge carrier transfer dynamics at the heterojunction of NW/QD were studied employing time resolved photoluminescence spectroscopy (TRPL). A hypothesis on charge transfer kinetics, based on the experimental measurements, was provided. It was realized that photocharging of QDs is the main reason for substantial PL quench, when holes are not effectively removed from the photoexcited QDs by a hole-transporting medium. Furthermore, the TRPL measurements showed that the hole transfer rate by a polysulfide electrolyte is slower than that of an electron; one main reason in impeding the device performance in quantum dot-sensitized solar cells (QDSSC). The NW/QD heterojunction was deployed in the structure of a QDSSC. The current-voltage behavior of the cells under various conditions was characterized in both dark and light conditions. The underlying problems hindering the device performance were identified by these characterizations. Heterojunction of ZnO NWs with a GaN thin film was also deployed in the structure of an LED. The NWs were grown on GaN film using the hydrothermal method. The fabricated device exhibited light emission under both forward and reverse bias injection currents. The electroluminescence and PL characterizations revealed that the light emission from the fabricated device depends on the point defects and interface states of the two semiconductors.

Subjects/Keywords: Zinc Oxide; Nanowires; Quantum Dots; Cadmium selenide; Time Resolved Photoluminescence Spectroscopy; Quantum Dot-Sensitized Solar Cell; Light Emitting Diode

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Janfeshan, B. (2016). Development of Zinc Oxide Nanowires and Quantum Dot Incorporation for Photovoltaic Applications. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/10144

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Janfeshan, Bita. “Development of Zinc Oxide Nanowires and Quantum Dot Incorporation for Photovoltaic Applications.” 2016. Thesis, University of Waterloo. Accessed December 08, 2019. http://hdl.handle.net/10012/10144.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Janfeshan, Bita. “Development of Zinc Oxide Nanowires and Quantum Dot Incorporation for Photovoltaic Applications.” 2016. Web. 08 Dec 2019.

Vancouver:

Janfeshan B. Development of Zinc Oxide Nanowires and Quantum Dot Incorporation for Photovoltaic Applications. [Internet] [Thesis]. University of Waterloo; 2016. [cited 2019 Dec 08]. Available from: http://hdl.handle.net/10012/10144.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Janfeshan B. Development of Zinc Oxide Nanowires and Quantum Dot Incorporation for Photovoltaic Applications. [Thesis]. University of Waterloo; 2016. Available from: http://hdl.handle.net/10012/10144

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Waterloo

6. Kao, Manfred. An Intelligent Neural Network Controlled Atmospheric Pressure Spatial Atomic Layer Deposition System for Tunable Metal Oxide Thin Films.

Degree: 2018, University of Waterloo

URL: http://hdl.handle.net/10012/13642

► Atmospheric pressure spatial atomic layer deposition (AP-SALD) is a novel thin film fabrication technique to create conformal and pin-hole free films. The growth rate of… (more)

▼ Atmospheric pressure spatial atomic layer deposition (AP-SALD) is a novel thin film fabrication technique to create conformal and pin-hole free films. The growth rate of AP-SALD is hundreds of times greater than conventional vacuum based methods which makes AP-SALD particularly attractive for large-scale roll-to-roll manufacturing. In this work, an AP-SALD system was built from scratch, in situ characterization tools were developed to monitor film properties during the growth of the film, an artificial neural network (ANN) was trained to model the AP-SALD system and an inverse neural network algorithm was implemented to generate recipes to produce films with defined properties. A commercial controller was used to interface with all the sensors and actuators in the AP-SALD system. A time-optimal 5th order trajectory with a drift algorithm was implemented to oscillate the substrate stage back and forth, and a feedback control with feedforward and an anti-windup algorithm was used to maintain the temperature of the substrate during deposition. The position error of the stage was visually imperceptible after 1000 oscillations and the temperature settling time of the stage was around 10 minutes which was significantly less than the time required to set up the AP-SALD system. The AP-SALD system was able to repeatably deposit zinc oxide (ZnO) films with diethylzinc and water as precursors. In situ electrical and optical tools were developed to measure the resistivity, film thickness and bandgap during the deposition. A printed circuit board (PCB) was designed to act as the electrodes and the substrate. A source/measure unit along with custom electronics measured the resistance of the films. The ZnO film grew on the PCB in island formations before coalescing into a continuous film. The bulk resistivity of ZnO was found to be approximately 15 Ω·cm. Reflectance spectroscopy was used to measure the bandgap and thickness of the film during the deposition by fitting the spectrum to the Tauc-Lorentz model. A bandgap of 3.18 eV was found for ZnO films. The lowest growth rate achieved was 0.27 nm per ALD cycle indicating there is some mixing of the precursors. A shallow feedforward ANN was trained to model the AP-SALD. The mean squared error (MSE) of the training set and test set was 0.9792 and 1.3287, respectively, indicating a good fit that can generalize well to new data. An inverse neural network algorithm was implemented to find the deposition parameters given the desired film properties. Since there may be infinite solutions, the algorithm returns the first optimal solution. The MSE of the estimated parameters were 2.5851E-14 indicating the algorithm was able to accurately inverse the AP-SALD model.

Subjects/Keywords: Atmospheric; Pressure; Spatial; Atomic; Layer; Deposition; Zinc Oxide; Thin; Film; Neural Network; Machine Learning; In Situ; Characterization; Tauc-Lorentz

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Kao, M. (2018). An Intelligent Neural Network Controlled Atmospheric Pressure Spatial Atomic Layer Deposition System for Tunable Metal Oxide Thin Films. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/13642

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Kao, Manfred. “An Intelligent Neural Network Controlled Atmospheric Pressure Spatial Atomic Layer Deposition System for Tunable Metal Oxide Thin Films.” 2018. Thesis, University of Waterloo. Accessed December 08, 2019. http://hdl.handle.net/10012/13642.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Kao, Manfred. “An Intelligent Neural Network Controlled Atmospheric Pressure Spatial Atomic Layer Deposition System for Tunable Metal Oxide Thin Films.” 2018. Web. 08 Dec 2019.

Vancouver:

Kao M. An Intelligent Neural Network Controlled Atmospheric Pressure Spatial Atomic Layer Deposition System for Tunable Metal Oxide Thin Films. [Internet] [Thesis]. University of Waterloo; 2018. [cited 2019 Dec 08]. Available from: http://hdl.handle.net/10012/13642.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Kao M. An Intelligent Neural Network Controlled Atmospheric Pressure Spatial Atomic Layer Deposition System for Tunable Metal Oxide Thin Films. [Thesis]. University of Waterloo; 2018. Available from: http://hdl.handle.net/10012/13642

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

7. Zhou, Qiong. Synthesis of Vertically-Aligned Zinc Oxide Nanowires and Their Applications as Photocatalysts.

Degree: 2013, University of Waterloo

URL: http://hdl.handle.net/10012/7732

► Zinc oxide (ZnO) nanostructures, especially nanowires, have been one of the most important semiconductive materials used for photocatalysis due to their unique material properties and… (more)

▼ Zinc oxide (ZnO) nanostructures, especially nanowires, have been one of the most important semiconductive materials used for photocatalysis due to their unique material properties and remarkable performance. In this project, vertically-aligned ZnO nanowires on glass substrate have been synthesized by using the facile hydrothermal methods with the help of pre-coated ZnO seeding layer. The crystalline structure, morphology and UV-Vis transmission spectra of the as-synthesized sample were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and Ultra-violet Visible (UV-Vis) Spectrophotometer. The photocatalytic activity of the sample was examined for the photocatalytic degradation of methyl orange (MO) as the test dye in aqueous solution under UV-A irradiation. The extent of direct hydrolysis of the MO dye under UV light without the photocatalysts was first measured to eliminate the possible contribution from the undesired variables to the overall efficiency. The effects of pH and initial concentration of the MO solution, as well as the nanowire growth time, on the photocatalytic efficiency have been investigated, in order to determine the optimal conditions for photocatalytic applications of ZnO nanowires in the industry. Furthermore, the reproducibility of the experimental methods used in this project was tested to ensure the reliability of the experimental results obtained; and the reusability of the prepared ZnO nanowire arrays were also evaluated to investigate the stability of the products for photocatalytic applications in a large scale. In addition, a micro-chamber based microfluidic device with integrated ZnO nanowire arrays has been fabricated and used for photodegradation studies of MO solution under continuous-flow conditions. As expected, the micro-chamber based approach exhibited much improved photodegradation efficiency as compared to the conventional method using bulk dye solution. The effects of the flow rate and chamber height of the microfluidic device have also been investigated in order to determine the optimal experimental conditions for photodegradation reactions in microfluidic devices.

Subjects/Keywords: Zinc Oxide; Nanowires; Photocatalysis; Hydrothermal Synthesis; Methyl Orange

…light by the TiO2 particles dispersed in the water suspension [66]. 2.4 Zinc Oxide… …Photocatalysts 2.4.1 Crystal Structures of ZnO Zinc oxide (ZnO) is a II-VI semiconductor with… …zinc blende unit cell. The light grey or yellow spheres denote oxygen, and dark or blue ones… …denote zinc, respectively (retrieved from http://www.wikipedia.org/)… …spheres denote oxygen, and dark or blue ones denote zinc, respectively (retrieved from http…

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APA (6^th Edition):

Zhou, Q. (2013). Synthesis of Vertically-Aligned Zinc Oxide Nanowires and Their Applications as Photocatalysts. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/7732

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Zhou, Qiong. “Synthesis of Vertically-Aligned Zinc Oxide Nanowires and Their Applications as Photocatalysts.” 2013. Thesis, University of Waterloo. Accessed December 08, 2019. http://hdl.handle.net/10012/7732.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Zhou, Qiong. “Synthesis of Vertically-Aligned Zinc Oxide Nanowires and Their Applications as Photocatalysts.” 2013. Web. 08 Dec 2019.

Vancouver:

Zhou Q. Synthesis of Vertically-Aligned Zinc Oxide Nanowires and Their Applications as Photocatalysts. [Internet] [Thesis]. University of Waterloo; 2013. [cited 2019 Dec 08]. Available from: http://hdl.handle.net/10012/7732.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Zhou Q. Synthesis of Vertically-Aligned Zinc Oxide Nanowires and Their Applications as Photocatalysts. [Thesis]. University of Waterloo; 2013. Available from: http://hdl.handle.net/10012/7732

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

8. Salgado, Shehan. Graphene Encapsulation for Cells: A Bio-Sensing and Device Platform.

Degree: 2014, University of Waterloo

URL: http://hdl.handle.net/10012/8391

► The generation of new nanoscale fabrication techniques is both novel and necessary for the generation of new devices and new materials. Graphene, a heavily studied… (more)

▼ The generation of new nanoscale fabrication techniques is both novel and necessary for the generation of new devices and new materials. Graphene, a heavily studied and versatile material, provides new avenues to generate these techniques. Graphene’s 2-dimensional form remains both robust and uncommonly manipulable. In this project we show that graphene can be combined with the yeast cell, Saccharomyces cerevisiae, arguably the most studied and utilized organism on the planet, to generate these new techniques and devices. Graphene oxide will be used to encapsulate yeast cells and we report on the development of a method to electrically read the behaviour of these yeast cells. The advantage of an encapsulation process for a cell sensor is the ability to create a system that can electrically show both changes in ion flow into and out of the cell and mechanical changes in the cell surface. Since the graphene sheets are mechanically linked to the surface of the cell, stresses imparted to the sheets by changes in the cell wall or cell size would also be detectable. The development process for the encapsulation will be refined to eradicate excess gold on the yeast cells as well as to minimize the amount of stray, unattached graphene in the samples. The graphene oxide encapsulation process will also be shown to generate a robust substrate for material synthesis. With regards to cell sensing applications, sources of noise will be examined and refinements to the device setup and testing apparatus explored in order to magnify the relevant electrical signal. The spherical topography of an encapsulated yeast cell will be shown to be an advantageous substrate for material growth. Zinc oxide, as a sample material being investigated for its own applications for photovoltaics, will be grown on these substrates. The spherical nature of the encapsulated cell allows for radial material growth and a larger photo-active area resulting in a device with increased efficiency over a planar complement. The zinc oxide nanorods are grown via an electrochemical growth process which also reduces the graphene oxide sheets to electrochemically reduced graphene. XRD analysis confirms that the material synthesized is infact zinc oxide. The nanorods synthesized are 200nm to 400nm in width and 1µm in length. The increase efficiency of the non-planar device and the effectiveness of the encapsulated cell as a growth substrate indicate encapsulated cells as a research avenue with significant potential.

Subjects/Keywords: Graphene; graphene oxide; Yeast; Zinc Oxide; Solar Cell; Biosensing; Saccharomyces cerevisiae

…chapter 2 we give some brief background information on graphene, zinc oxide, Saccharomyces… …functionalizability and versatility of graphene is explored through a method to synthesize zinc oxide… …2.7 Zinc Oxide Zinc Oxide is a material with a wide variety of applications in electronics… …Zinc Oxide nanostructures are richly varied in morphology, among the most numerous of those… …this project. 3.7 Zinc Oxide growth An electrochemical process was used for the generation…

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APA (6^th Edition):

Salgado, S. (2014). Graphene Encapsulation for Cells: A Bio-Sensing and Device Platform. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/8391

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Salgado, Shehan. “Graphene Encapsulation for Cells: A Bio-Sensing and Device Platform.” 2014. Thesis, University of Waterloo. Accessed December 08, 2019. http://hdl.handle.net/10012/8391.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Salgado, Shehan. “Graphene Encapsulation for Cells: A Bio-Sensing and Device Platform.” 2014. Web. 08 Dec 2019.

Vancouver:

Salgado S. Graphene Encapsulation for Cells: A Bio-Sensing and Device Platform. [Internet] [Thesis]. University of Waterloo; 2014. [cited 2019 Dec 08]. Available from: http://hdl.handle.net/10012/8391.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Salgado S. Graphene Encapsulation for Cells: A Bio-Sensing and Device Platform. [Thesis]. University of Waterloo; 2014. Available from: http://hdl.handle.net/10012/8391

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

9. Kinadjian, Natacha Monique Frédérique. Integrative Chemistry based morphosyntheses of hierarchical composite materials for photovoltaic, photocatalysis and photoluminescence applications.

Degree: 2014, University of Waterloo

URL: http://hdl.handle.net/10012/8374

► The shaping of functional materials and the control of their texture at all length scales are sine qua non conditions for the improvement of current… (more)

Subjects/Keywords: sol-gel; titanium dioxide; zinc oxide; material shaping; fibers; liquid crystals; integrative chemistry; polypyrrole

…zinc oxide (ZnO)/ polyvinyl alcohol (PVA) macroscopic fibers. For this… …oxide framework with a continuous dehydration via oxolation reactions, (ii) a… …spheres and not a porous solid. They have been especially used for the synthesis of metal oxide…

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Kinadjian, N. M. F. (2014). Integrative Chemistry based morphosyntheses of hierarchical composite materials for photovoltaic, photocatalysis and photoluminescence applications. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/8374

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Kinadjian, Natacha Monique Frédérique. “Integrative Chemistry based morphosyntheses of hierarchical composite materials for photovoltaic, photocatalysis and photoluminescence applications.” 2014. Thesis, University of Waterloo. Accessed December 08, 2019. http://hdl.handle.net/10012/8374.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Kinadjian, Natacha Monique Frédérique. “Integrative Chemistry based morphosyntheses of hierarchical composite materials for photovoltaic, photocatalysis and photoluminescence applications.” 2014. Web. 08 Dec 2019.

Vancouver:

Kinadjian NMF. Integrative Chemistry based morphosyntheses of hierarchical composite materials for photovoltaic, photocatalysis and photoluminescence applications. [Internet] [Thesis]. University of Waterloo; 2014. [cited 2019 Dec 08]. Available from: http://hdl.handle.net/10012/8374.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Kinadjian NMF. Integrative Chemistry based morphosyntheses of hierarchical composite materials for photovoltaic, photocatalysis and photoluminescence applications. [Thesis]. University of Waterloo; 2014. Available from: http://hdl.handle.net/10012/8374

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

10. Iheanacho, Bright. Optoelectronic Properties and Applications of 3-D Hybrid a-Si:H/ZnO Nanowire Structures.

Degree: 2017, University of Waterloo

URL: http://hdl.handle.net/10012/12352

► This Ph.D. dissertation presents the study and development of optoelectronic properties of 3-D hybrid zinc oxide nanowire (ZnO NW) and hydrogenated amorphous silicon (a-Si:H) core-shell… (more)

▼ This Ph.D. dissertation presents the study and development of optoelectronic properties of 3-D hybrid zinc oxide nanowire (ZnO NW) and hydrogenated amorphous silicon (a-Si:H) core-shell structures and a demonstration of their application in infrared photodiodes. In addition, the demonstration of infrared photoconductors using the 3-D a-Si:H/ZnO NW structure, which are then integrated onto conventional back channel etched (BCE) a-Si:H thin film transistors (TFTs) for potential large-area sensor applications is also presented. A hybrid 3-D core-shell structure formed using ZnO NW cores and conformally coated a-Si:H thin film shell was found to be infrared sensitive for wavelengths up to 2.5 µm wavelength. Scattering and multiple reflection enabled by the 3-D morphology were found to enhance the effective thickness of the a-Si:H shell by ~3 orders of magnitude. With the enhanced effective thickness, defects within the a-Si:H material were associated with enabling infrared absorption, achieving up to 73% infrared absorption at 2.3 µm infrared wavelength for 500 nm coated a-Si:H film on 7 µm long ZnO NWs having a nanowire density of 4.3 × 107 NW/cm2. Comprehensive materials and device characteristics were studied to show a defect mediated infrared absorption process in the 3-D a-Si:H/ZnO NW material system. 3-D infrared photoconductors were fabricated afterwards at a temperature of ≤ 150°C using the infrared sensitive 3-D a-Si:H/ZnO NW hybrid material system. An intentional ‘NW gap’ was created between the edge of the NW array and the contacts of the infrared photoconductors to minimize parasitic conduction from conductive and connected NWs thereby reducing the dark current of the 3-D photoconductor. An ON/OFF ratio of 3.2 × 102 was achieved for 1 µm thick a-Si:H shell coating on 2.7 µm long ZnO NWs with a nanowire density of 3.9 × 108 NW/cm2 using 1.55 µm LED illumination. As an alternative infrared photodetector, 3-D infrared photodiodes were also fabricated using similar process conditions. Dark current as low as 1.6 × 10-9 A/cm2 was achieved for a diode with NW length vs a-Si:H thickness ratio of 1.5× and NW density of 6.1 × 107 NW/cm2 giving an infrared signal to noise ratio of 2.5 × 102 with 1.55 µm LED irradiation. The factors that influence the dark currents were studied and several optimizations were implemented. The top contact was optimized by replacing aluminum doped zinc oxide (AZO) top conducting oxide (TCO) with thinned-down, conductive gallium indium zinc oxide (GIZO) and p+ doped a-Si:H to minimize the window layer absorption and enhance the its infrared transmission. 3-D infrared photoconductors were also integrated onto a-Si:H BCE TFT at a process temperature ≤ 150°C. The process development and the effects of both the structure and the integration process flow were evaluated. A 3× signal to noise ratio due to infrared irradiation using a heat lamp was obtained for the integrated device with a photoconductor section that contains only 20% 3-D a-Si:H/ZnO NW structure.

Subjects/Keywords: ZnO NW; a-Si:H; 3-D Material; Core - Shell Structure; Infrared detector; Optoelectronics; zinc oxide nanowire; amorphous silicon

…35 3.2 Zinc Oxide (ZnO) Nanowire (NW) Characterization… …36 Fig 3.2 (a) Disordered zinc oxide nanowires (ZnO NWs) grown from a… …AZO: Aluminum doped zinc oxide B: Boron B2H6: Diborane c-Si: Crystalline silicon Cr: Chrome… …GaN: Gallium nitride Ge: Germanium GIZO: Gallium indium zinc oxide H: Hydrogen HCl… …Silicon Silane Silicon nitride Silicon oxide Transparent conductive oxide Zinc Zinc oxide PECVD…

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Iheanacho, B. (2017). Optoelectronic Properties and Applications of 3-D Hybrid a-Si:H/ZnO Nanowire Structures. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/12352

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Iheanacho, Bright. “Optoelectronic Properties and Applications of 3-D Hybrid a-Si:H/ZnO Nanowire Structures.” 2017. Thesis, University of Waterloo. Accessed December 08, 2019. http://hdl.handle.net/10012/12352.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Iheanacho, Bright. “Optoelectronic Properties and Applications of 3-D Hybrid a-Si:H/ZnO Nanowire Structures.” 2017. Web. 08 Dec 2019.

Vancouver:

Iheanacho B. Optoelectronic Properties and Applications of 3-D Hybrid a-Si:H/ZnO Nanowire Structures. [Internet] [Thesis]. University of Waterloo; 2017. [cited 2019 Dec 08]. Available from: http://hdl.handle.net/10012/12352.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Iheanacho B. Optoelectronic Properties and Applications of 3-D Hybrid a-Si:H/ZnO Nanowire Structures. [Thesis]. University of Waterloo; 2017. Available from: http://hdl.handle.net/10012/12352

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

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