Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 21 for “"multicrystalline"”.
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Texturization of multicrystalline silicon solar cells
… truly successful, especially when applied to multicrystalline wafers.
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Dislocation density reduction in multicrystalline silicon through cyclic annealing
Multicrystalline silicon solar cells are an important renewable energy technology that have the potential to provide the world with much of its energy. While they are relatively inexpensive, their efficiency is limited by material defects, and in particular by dislocations. Reducing dislocation …
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Characterization of residual stresses in birefringent materials applied to multicrystalline silicon wafers
… retardation in crystalline materials. Single and multicrystalline silicon was chosen as the model material. Silicon is an interesting and important material in its own right, and the use of photoelasticity to determine stresses at linear and planar defects can have important consequences in the …
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Formation of screen-printed contacts on multicrystalline silicon (mc-Si) solar cells
Commercial multicrystalline silicon (me-Si) solar cells use screen-printing process for depositing both the Ag paste based gridded front and Al based back (whole area) metal contacts.. This thesis relates to experimental and theoretical studies of contact formation mechanisms in silicon solar …
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Root cause defect identification in multicrystalline silicon for improved photovoltaic module reliability
… substrate to enable this scale-up is cast multicrystalline silicon (mc-Si) due to its low operating cost and capital requirements compared to other technologies. However, a new form of light-induced degradation was discovered when transitioning mc-Si to the latest high efficiency device …
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Sacrificial high-temperature phosphorus diffusion gettering for lifetime improvement of multicrystalline silicon wafers
… Rs (p-type) are required [1]. For cost-effective multicrystalline silicon wafers, achieving this lifetime often requires gettering. Gettering at higher temperatures for longer times is often necessary to fully dissolve and remove precipitated impurities. However, such time temperature profiles can …
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Surface and bulk passivation of multicrystalline silicon solar cells by silicon nitride (H) layer : modeling and experiments
… silicon nitride (SiN :H) antireflection layer on multicrystalline silicon (me-Si) solar cells. The passivation of silicon surface can be achieved in two ways: by field-effect passivation and/or by neutralization of interface states. In other words, the deposition should result in a high value of …
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Application of infrared birefringence imaging for measuring residual stress in multicrystalline, quasi-mono, dendritic web, and string ribbon silicon for solar cells
One of the parameters with highest impact on photovoltaic module cost is manufacturing yield during solar cell production. Yield is, to a great extent, directly affected by the crystallization technique used to grow the substrate wafers due to its role in generating residual stresses that can lead …
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Structure and Motion of Charge Density Waves: An Nmr Study of Niobium-Selenide(3)
… wave (CDW) conductor, NbSe(,3), using aligned, multicrystalline samples, observing the NMR with and without current flow in the crystals.
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High-temperature defect engineering for silicon solar cells : predictive process simulation and synchrotron-based microcharacterization
… that iron remains in heavily-contaminated multicrystalline materials after a typical industrial phosphorus diffusion. Similar measurements of the iron-silicide precipitate distribution in multicrystalline silicon samples before and after higher-temperature gettering steps confirm that the …
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Applications of Spectrally-Resolved Photoluminescence in Silicon Photovoltaics
… distributed around sub-grain boundaries in multicrystalline silicon wafers. The thesis shows that, the dislocations at sub-grain boundaries and the defects and impurities trapped around the dislocations emit separate luminescence peaks at low temperatures. The luminescence intensity of the …
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Applications of Spectrally-Resolved Photoluminescence in Silicon Photovoltaics
… distributed around sub-grain boundaries in multicrystalline silicon wafers. The thesis shows that, the dislocations at sub-grain boundaries and the defects and impurities trapped around the dislocations emit separate luminescence peaks at low temperatures. The luminescence intensity of the …
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Influence of defects and impurities on solar cell performance
Multicrystalline silicon (mc-Si) solar cells exhibit high impurity content and higher density of crystal defects such as grain boundaries, dislocations, stacking faults and impurity precipitates. Even though the effect of dislocations on mc-Si solar cell performance has been studied, a severe lack …
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Electrical impact assessment of dislocations in silicon materials for solar cells
Cast multicrystalline silicon (mc-Si) makes up about 60% of the global photovoltaics market production, and is favored due to its lower areal and capex costs relative to monocrystalline silicon. This method, however, produces material with a higher density of defects (e.g., dislocations, grain …
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Metal impurities in n-type crystalline silicon for photovoltaics : simulation, synchrotron-based characterization, and mitigation
… substitute for the currently dominant p-type multicrystalline silicon (mc-Si) wafer. This thesis explores one class of wafer substitute: n-type silicon. This material is thought to have higher defect tolerance than p-type, but practical mc-Si cell efficiencies have remained lower than in …
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Detecting and gettering chromium impurities in photovoltaic crystalline silicon
… to study chromium (Cr) distributions in multicrystalline silicon in as-grown material and after two phosphorous diffusion profiles. I complement quantified precipitate size and spatial distribution with interstitial Cr concentration and minority carrier lifetime measurements to provide …
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Hot-wire chemical vapour deposition of nanocrystalline silicon and silicon nitride : growth mechanisms and filament stability
… antireflective and passivating layers for multicrystalline silicon solar cells. Research into the synthesis and characterization of nc-Si:H and SiNₓ thin films is vital from a renewable energy aspect. In this thesis we investigated the film growth mechanisms and the filament stability …
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Development and application of the scanning Kelvin probe for solar cell defect analysis.
… top of the Si3Ni4 passivation layer on a mc-Si (Multicrystalline silicon) solar cell. Furthermore a high resolution SKP has successfully produced images showing direct evidence of polytype related surface potential variations caused by the surface orientations of mc-Si. The Kelvin probe was …
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Structure and motion of charge density waves, and NMR study of NbSe3
… wave (COW) conductor, NbSe3 , using aligned, multicrystalline samples, observing the NMR with and without current flow in the crystals. Above 144 K, where no COW's are present, an orientation and field-dependence NMR study is presented. Three Nb NMR sites are identified, and associated with …
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Nucleation and solidification of silicon for photovoltaics
… process, a new method for making high-quality multicrystalline wafers without sawing is under development. This method begins with a poorly-structured silicon wafer made by a low-cost method which is then coated by a thin film capsule. The encapsulated wafer is zone-melted and recrystallized, …
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