Browsing Institutt for materialteknologi by Issue Date
Now showing items 201-220 of 2534
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Dislocations in Multicrystalline Silicon for Solar Cells: Microstructure and Sources
(Doktoravhandlinger ved NTNU, 1503-8181; 2012:169, Doctoral thesis, 2012)The study of defects especially dislocations and grain boundaries in semiconductors has received a great deal of attention for over 60 years, primarily due to the importance of the defects in microelectronics. The defect ... -
SAG-FW Welding of C90 Riser Steel Connectors
(Master thesis, 2012)Weld simulations have been conducted on a C90 quenched tempered steel used in offshore riser systems, in order to investigate the possibility of introducing an effective solid state weld procedure. As a secondary objective, ... -
Analysis of an Impedance Model for Porous Semiconductor Electrodes
(Master thesis, 2012)The main aim of this work was to analyze an impedance model for porous semiconductor electrodes consisting of spherical particles. The model should make it possible to analyze the flatband potential for this type of ... -
Investigation of the Red Zone of Multicrystalline Silicon Ingots for Solar Cells
(Doktoravhandlinger ved NTNU, 1503-8181; 2012:184, Doctoral thesis, 2012)This thesis is dealing with the “Red Zone” of multicrystalline silicon (mc-Si) ingots, a region which exhibits low performances and which is usually removed before slicing the wafers for solar cells fabrication. It is ... -
Stål i beskyttelseskonstruksjoner: Introduksjon av Al2O3 til stålmatriks for økt penetrasjonsmotstand
(Master thesis, 2012)Lette våpen som håndvåpen, rifler og granater står for de fleste dødsfall i moderne konflikter, og behovet for robuste materialer til vern mot slike våpen er stort. Denne rapporten har tatt sikte på å avdekke hvilken effekt ... -
Effect of B-site substitution on the stability of La0.2Sr0.8Fe0.8B0.2O3-delta, B = Al, Ga, Cr, Ti, Ta, Nb
(Journal article; Peer reviewed, 2012)Single phase, cubic perovskites of composition La0.2Sr0.8Fe0.8B0.2O3 − δ, B = Al, Ga, Cr, Ti, Ta and Nb, were prepared by spray pyrolysis from aqueous precursor solutions. The effect of B-site substitution on the stability ... -
Impurity distribution and reduction behaviour of quartz in the production of high purity silicon
(Doktoravhandlinger ved NTNU, 1503-8181; 2012:182, Doctoral thesis, 2012)The production of solar grade silicon is based on the use of expensive high purity carbon and quartz feedstock as well as various silicon refining techniques. Impurities in the feedstock materials enter the silicon during ... -
Oxidation of silicon powder in humid air
(Master thesis, 2012)Silicon undergoes oxidation at room temperature, causing a formation of an oxide layer on its surface. Gaining knowledge about the oxide layer formed during ageing, is valuable with regards to production of high quality ... -
As Cast and Rapidly SolidifiedTi-V Alloys for Selective Hydrogen Absorption
(Doctoral Theses at NTNU, 1503-8181; 2012:204, Doctoral thesis, 2012)Steam reforming of hydrocarbons is a dominant technology in the commercial production of hydrogen. Hydrogen Sorption Enhanced Reforming (HSER) is a novel concept recently proposed by Statoil, with the aim of increasing the ... -
Electro-oxidation of small organic molecules
(Doktoravhandlinger ved NTNU, 1503-8181; 2012:348, Doctoral thesis, 2012)An alternative to fossil fuels is to utilize biofuels like methanol and ethanol directly in fuel cells. One drawback of this system is the sluggish reaction kinetics in methanol and ethanol oxidation where strongly bound ... -
Lifetime degradation in n-type Cz-Si
(Master thesis, 2012)The main object was to investigate the effect of donors, thermal donors and defects on the lifetime on n-type Czochralsky (Cz) silicon. Cz is a technique for making monocrystals by dipping a monocrystalline seed into the ... -
Intragranular Chromium Nitride Precipitates in Duplex and Superduplex Stainless Steel
(Master thesis, 2012)Intragranular chromium nitrides is a phenomenon with detrimental effects on material properties in superduplex stainless steels which have not received much attention. Precipitation of nitrides occurs when the ferritic ... -
Composition and Surface Modifications of Silica Structures in Diatiom Frustules by Incorporation of Functional Oxides and Nitride Formation
(Master thesis, 2012)Renewable energy production featuring silicon photovoltaic solar cells are of considerable interest to reduce pollution and related environmental changes. Improvements in efficiency along with reductions in cost are key ... -
Electrochemical Passivation and Texturing of Silicon Wafers in Alkaline Solutions
(Doktoravhandlinger ved NTNU, 1503-8181; 2012:339, Doctoral thesis, 2012)Texturing of silicon wafers is an important process step in fabrication of solar cells in order to reduce the reflection of incoming light radiation on the solar cell surfaces. The conventional wet chemical etching methods ... -
Finite element analysis of strain distribution in ZK60 Mg alloy during cyclic extrusion and compression
(Journal article; Peer reviewed, 2012)Finite element method was used to study the strain distribution in ZK60 Mg alloy during multi-pass cyclic extrusion and compression (CEC). In order to optimize the CEC processing, the effects of friction condition and die ... -
Investigating thermal donors in n-type Cz silicon with carrier density imaging
(Journal article; Peer reviewed, 2012)A new method to map the thermal donor concentration in silicon wafers using carrier density imaging is presented. A map of the thermal donor concentration is extracted with high resolution from free carrier density images ... -
Organic binder as a substitute for bentonite in ilmenite pelletization
(Master thesis, 2012)TiZir Titanium & Iron produces high titania slag and high purity pig iron from ilmenite in Tyssedal. The ilmenite is pelletized before smelting. Bentonite is added to the ilmenite concentrate as a binder to give the pellets ... -
Electro-oxidation of ethanol at Pt electrodes with the use of a Dynamic Electrochemical Impedance Spectroscopy (DEIS) technique
(Master thesis, 2012)Electro-oxidation of ethanol on smooth platinum surfaces was studied in thetemperature range 21C to 140C for 0.2 M ethanol in 0.5 M sulphuric acid.This was done by use of cyclic voltammetry and electrochemical impedances ... -
PVA-assisted combustion synthesis and characterization of porous nanocomposite Li2FeSiO4/C
(Journal article; Peer reviewed, 2012)Porous Li2FeSiO4/C nanocomposites were synthesized by a PVA-assisted combustion method, and phase pure Li2FeSiO4 was produced for samples prepared with 20 and 30 wt.% starch. The electrochemical properties of the Li2FeSiO4/C ... -
Optimization of EBSD parameters for ultra-fast characterization
(Journal article; Peer reviewed, 2012)Ultra-fast pattern acquisition of electron backscatter diffraction and offline indexing could become a dominant technique over online electron backscatter diffraction to investigate the microstructures of a wide range of ...