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High Performance And Low Cost Passivating, Carrier-Selective Contacts For Silicon Photovoltaics, Jannatul Ferdous Mousumi
High Performance And Low Cost Passivating, Carrier-Selective Contacts For Silicon Photovoltaics, Jannatul Ferdous Mousumi
Electronic Theses and Dissertations, 2020-
The world is now focusing on expanding renewable energy sources to reduce the carbon footprint and mitigate climate change. Solar energy is one of the most environment-friendly and fastest-growing renewable energy sources in the present world. While crystalline silicon (c-Si) based devices dominate the global photovoltaics (PV) market with a current share of 95%, it is still challenging to achieve the theoretical efficiency limit of 29.4% with this technology due to a few performance limiting factors. Contact recombination losses are dominant among them which result from the recombination of photo-generated charge carriers due to the presence of defects at the …
From Field To Failure: Detecting And Understanding Reliability Defects In Crystalline Silicon Photovoltaics, Dylan Colvin
From Field To Failure: Detecting And Understanding Reliability Defects In Crystalline Silicon Photovoltaics, Dylan Colvin
Electronic Theses and Dissertations, 2020-
Severe pollution levels and the growing influence of climate change have shown that dirty energy sources need renewable and sustainable replacements. The field of photovoltaics (PV) has grown substantially over the years from a niche space solar market to a commodity in large part due to improvements in reliability. Reliability of all materials in a PV module must be considered. The industry has seen an explosion of innovation in cell interconnection technologies with significant market penetration in the past several years. These emerging, less mature technologies require more reliability information to guide improvements. Degradation studies of long-term outdoor exposure and …
Influence Of Growth Parameters On The Synthesis Of Mos2 Films, Victor Okonkwo
Influence Of Growth Parameters On The Synthesis Of Mos2 Films, Victor Okonkwo
Honors Undergraduate Theses
Information processing is crucial in modern society, placing a great emphasis on the performance of optoelectronic devices to match ever increasing processing and memory needs. Within these devices, MoS2 has demonstrated great potential as transistors due to its enhanced electrostatic control. As increased layer thickness of quality MoS2 films have been shown to boost the performance of its transistors, growth parameters for the synthesis of ideally uniform and large area multilayered films via chemical vapor deposition were investigated. By increasing the flow pressure in the system and the growth time, increasing levels of thickness and nucleation density was …
Improving The Performance And Durability Of Metal Contacts In Crystalline Silicon Solar Cells Using Advanced Characterization, Nafis Iqbal
Electronic Theses and Dissertations, 2020-
Solar energy is one of the fastest growing forms of energy generation due to its low cost, lack of emissions, minimal maintenance, and excellent durability. However, like any other technology, it is also not free from defects and degradation, which limit its performance in the real world. Most of the degradation is related to metal contacts, which also happens to be one of the most expensive items in manufacturing, comprising almost half of the cost of converting a silicon wafer into a photovoltaic (PV) cell. Therefore, studying contact degradation to make them reliable and free of defects is the key …
Engineering The Electrode Properties For Developing High Performance Supercapacitors, Kowsik Sambath Kumar
Engineering The Electrode Properties For Developing High Performance Supercapacitors, Kowsik Sambath Kumar
Electronic Theses and Dissertations, 2020-
Rising global warming concern demands the need for a rapid transition to renewable energy sources. The intermittent nature of these sources emphasizes the requirement of developing highly efficient electrochemical energy storage devices like supercapacitors and batteries. Supercapacitors are at the forefront of powering various devices spanning from electric cars to aircraft. Here, we have engineered the electrode material properties for developing supercapacitors with high capacitance, energy density and cycle life. Among the electrode materials, we have focused on improving the energy storage performance of 2D materials like graphene oxide (GO) and tungsten disulfide (WS2), in addition to metal oxides such …
The Effect Of Heat Transfer On Microstructural Development For Inconel718 Nickel-Based Superalloy In Laser Powder Bed Fusion, Erica Drobner
The Effect Of Heat Transfer On Microstructural Development For Inconel718 Nickel-Based Superalloy In Laser Powder Bed Fusion, Erica Drobner
Electronic Theses and Dissertations, 2020-
Inconel 718 (IN718) is a superalloy with excellent corrosion resistance and high temperature stability, giving rise to its popular use in the aerospace industry as well as other high performing applications. This study utilizes the relatively low conductivity of IN718 to focus in on the heat transfer procedures in which occur during the laser powder bed fusion (LPBF) manufacturing process of metals. Cylindrical samples of constant geometry with varying dimensions of thermal supports were fabricated using a compatible IN718 build plate. As thermal support size increased, heat dissipation to the build plate consequently increased. Theoretically, this modification of heat transfer …
In Situ Transmission Electron Microscopy And Ab Initio Study Of The Electrochemomechanical Effect Of Lithium Penetration In Electrolytes For All-Solid-State Batteries, Megan Diaz
Electronic Theses and Dissertations, 2020-
Although the past twenty years have seen dramatic advancement in lithium-ion batteries (LIBs), these batteries are nearing their theoretical limit. Next generation energy storage technologies must therefore be developed to meet the ever-increasing demands for batteries with higher capacity, longer cycle lifetime, and increased safety. All-solid-state lithium battery (ASSLIB) technology is one of the promising candidates. It is equipped with a solid-state electrolyte (SSE) replacing the flammable organic liquid electrolyte used in current LIBs. The SSE's high modulus is expected to prevent lithium dendrites and enables the use of a lithium metal anode to contribute to its high capacity without …
Designing Physical And Chemical Confinement In Lithium Sulfur Battery Cathode For Suppression Of Shuttle Effect, Saisaban Fahad
Designing Physical And Chemical Confinement In Lithium Sulfur Battery Cathode For Suppression Of Shuttle Effect, Saisaban Fahad
Electronic Theses and Dissertations, 2020-
Lithium sulfur batteries (LSBs) are attracting attention as a next generation energy storage device because of their high energy density (2670WhKg-1), high specific capacity (1675 mAhg-1), low cost and environmental friendliness. However, there are several challenges that need to be overcome before LSBs can be implemented in general applications. This is due to the low electric conductivities of sulfur and lithium sulfide and large volume changes during charge/discharge cycling. Also, most importantly, the dissolution of lithium polysulfides into the electrolyte during cycling leads to capacity decay and low coulombic efficiency. Additionally, these lithium polysulfides can diffuse to the lithium anode …
Davydov-Split Aggregates Of Cyanine Dyes For Bovine Serum Albumin Detection, Yiping Ma
Davydov-Split Aggregates Of Cyanine Dyes For Bovine Serum Albumin Detection, Yiping Ma
Electronic Theses and Dissertations, 2020-
The p-conjugated supramolecular aggregates have gained significant interest in recent years. The cyanine dye aggregates are particularly interesting due to their unique optical and excitonic properties, which cannot be found in individual molecules. Cyanine dyes can form different kinds of aggregates. H-aggregates are formed when dye molecules are packed in a face-to-face fashion, which gives rise to a blue-shift absorption band and strong emission quenching compared to the monomer. J-aggregates are composed of individual dye molecules in a head-to-tail stacking, which leads to a red-shift absorption band and a sharp intense emission band with a small Stoke shift compared with …
Processing-Microstructure-Property Correlation For 316l Stainless Steel Manufactured By Laser Powder Bed Fusion, Nathalia Diaz Vallejo
Processing-Microstructure-Property Correlation For 316l Stainless Steel Manufactured By Laser Powder Bed Fusion, Nathalia Diaz Vallejo
Electronic Theses and Dissertations, 2020-
The microstructural development of 316L stainless steel (316L SS) was investigated over a wide range of systematically varied laser powder bed fusion (LPBF) parameters, such as laser power, laser scan speed, hatch distance, and volumetric energy density. The use of volumetric energy density between 46 and 127 J/mm3 produced samples with relative density above 99.8% demonstrating that even in the optimized range of processing parameters the pores are unavoidable. Shifting from this range through a variation of laser scan speed produced two types of flaws, lack of fusion (LoF) and keyhole (KH) porosity leading to a decrease in the relative …
Designing The Electrochemical Interface To Enable Lithium Metal Batteries, Supriya Koul
Designing The Electrochemical Interface To Enable Lithium Metal Batteries, Supriya Koul
Electronic Theses and Dissertations, 2020-
Although Li-ion battery is one of the most widely used energy storage devices, there have been extensive efforts to push its limit to meet the ever-increasing demands to improve its energy density for applications such as electric vehicles, portable electronics, and grid storages. Here, Li metal anode plays a key role in the next generation energy storage devices, ultimately enabling the anode-free configuration. However, there are major challenges that need to be overcome for a successful deployment of anode-free batteries. These include designing a competitive SEI, low Coulombic efficiency, and the formation of dendrites. To realize an effective anode-free configuration …
Synchronous Raman Microspectroscopy And Laser Beam Induced Current Measurements As A Metrology Tool For Solar Cells And Optoelectronic Devices, Jeya Prakash Ganesan
Synchronous Raman Microspectroscopy And Laser Beam Induced Current Measurements As A Metrology Tool For Solar Cells And Optoelectronic Devices, Jeya Prakash Ganesan
Electronic Theses and Dissertations, 2020-
This works developed synchronous Raman microspectroscopy with laser beam induced current (LBIC) measurements to generate insights into structure-property correlations in finished solar cell modules. Raman spectroscopy is a powerful, non-destructive technique to examine phase and composition of materials where a laser beam excites characteristic vibrational modes of chemical bonds in a material. Conducting Raman spectroscopy under a microscope (i.e., Raman microspectroscopy) with confocal capabilities allows the chemical constituents to be mapped with high spatial resolution in the x, y and z directions. Simultaneously, the excitation laser from Raman can also generate photocarriers in a semiconductor. In a solar cell, these …