Search for dissertations about: "Intrinsic defect"

Showing result 1 - 5 of 51 swedish dissertations containing the words Intrinsic defect.

2. 1. Defect Engineering in Kesterite Materials for Thin Film Solar Cells

   Author : Katharina Rudisch; Jonathan J. Scragg; Alain Lafond; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CZTS; thin film solar cells; defect engineering; composition-spread films; order disorder transition; intrinsic defects; secondary phases; Teknisk fysik med inriktning mot elektronik; Engineering Science with specialization in Electronics;

   Abstract : Cu2ZnSnS4 has great potential to be applied as an earth abundant and non-toxic absorber material in thin film solar cells, based on its suitable optical properties. However, several challenges have prevented the achievable efficiencies from exceeding 12.6 %, which is well below marketable efficiencies compared to competing solar cell technologies. READ MORE

4. 2. On Defect Generation and the Appearance of Injection-Moulded Polymers

   Author : Francesco Pisciotti; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; colour; gloss; ageing; rheology; defect; mechanical properties; surface topography; recycling; polypropylene; injection moulding; mass spectroscopy; simulation; polystyrene;

   Abstract : This thesis addresses the generation of some important manufacturing defects associated with intrinsic limitations of the injection moulding process. These include bulk-surface structural discontinuities, particularly air traps and welds, bulk-surface compositional inhomogeneities and gloss and colour variations. READ MORE

5. 3. Defect Induced Room-Temperature Ferromagnetism in ZnO and MgO Thin FIlms and Device Development

   Author : Mukes Kapilashrami; Lyuba Belova; E Dan Dahlberg; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Room-temperature ferromagnetism; intrinsic defects; un-balanced balanced magnetron sputtering; magnetic anisotropy and photoconductivity; Materials science; Teknisk materialvetenskap;

   Abstract : This thesis presents the discovery of defect induced room-temperature ferromagnetism in industrially important ZnO and MgO thin films, and establishes from a systematic study, in both ZnO and MgO films, the unique phenomenon of the sequences of transitions from ferromagnetism to para-, and eventually the well known diamagnetism of the bulk as a function of film thickness. Highly oriented and high quality dense thin films of ZnO and MgO have been deposited by reactive (balanced) magnetron sputtering under different ambience conditions and deposition temperatures. READ MORE

6. 4. Point defect interactions and structural stability of compounds

   Author : Vitaly Baykov; Börje Johansson; Peter Mohn; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; first principles; ab initio; density functional theory; point defects interactions; diluted magnetic semiconductors; structural stability; zirconium alloys; Other materials science; Övrig teknisk materialvetenskap;

   Abstract : Theoretical studies of point defect interactions and structural stability of compounds have been performed using density functional theory. The defect-related properties, such as activation energy of diffusion, electronic and magnetic structure of selected materials have been studied. READ MORE

7. 5. Electronic properties of intrinsic defects and impurities in GaN

   Author : Tran Thien Duc; Carl Hemmingsson; Galia Pozina; Erik Janzén; Walter Meyer; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : With its outstanding properties such as a wide direct bandgap (3.4 eV), high electron mobility and high breakdown voltage, GaN and its alloys with In and Al are considered as one of the most important semiconductors for optoelectronic devices and high-power and high-frequency transistors. READ MORE