Search for dissertations about: "moiré structures"

Showing result 1 - 5 of 6 swedish dissertations containing the words moiré structures.

  2. 1. Optical properties of point defects in insulators and of transition metal dichalcogenides

    Author : Christopher Linderälv; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; luminescence quenching; charge transition levels; excitons; transition metal dichalcogenides; monolayer alloys; solid state lighting; color centers; oxygen vacancies; moiré structures; wide band gap oxides;

    Abstract : There is a need for new or modified materials, both to improve current devices and to create novel functionalities. Engineering materials to target specific functionalities requires a better understanding of how microscopic processes impact materials properties. READ MORE

  4. 2. Composites studied by moiré methods and high speed photography

    Author : L. Gunnar Melin; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Experimental Mechanics; Experimentell mekanik;

    Abstract : Fibre composites are today used as construction material in a growing number of applications. Carbon fibres/epoxy matrix composites are employed in high performance applications as aircrafts where a high stiffness/weight ratio is important. READ MORE

  5. 3. Ferroelectric domain engineering and characterization for photonic applications

    Author : Simonetta Grilli; Fredrik Laurell; Wolfgang Sohler; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; LiNbO; KTiOPO; interferometry; digital holography; electric field poling; electro-optic materials; holographic lithography; ferroelectric domains; nanostructures; microstructures; Optical physics; Optisk fysik;

    Abstract : Lithium niobate (LiNbO3) and KTiOPO4 (KTP) are ferroelectric crystals of considerable interest in different fields of optics and optoelectronics. Due to its large values of the nonlinear optical, electro-optic (EO), piezoelectric and acousto-optical coefficients, LiNbO3 is widely used for laser frequency conversion using the quasiphase matching (QPM) approach where the sign of nonlinearity has been periodically modulated by electric field poling (EFP). READ MORE

  6. 4. Transmission Electron Microscopy of III-V Nanowires and Nanotrees

    Author : Lisa Karlsson; Centrum för analys och syntes; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Technological sciences; Naturvetenskap; Natural science; nanowires; TEM; III-V; Teknik;

    Abstract : In this work, the morphology and crystal structure of epitaxial semiconductor nanowire structures grown by metal-organic vapour phase epitaxy (MOVPE) are studied by electron microscopy methods. In particular, the three-dimensional structure of nanowires and nanotrees has been characterised by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and multi-slice (MS) simulations. READ MORE

  7. 5. Functionalized Graphene as Superlattice and Gas Sensor

    Author : Tianbo Duan; Klaus Leifer; Andrey Turchanin; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; graphene; functionalization; gas sensor; superlattice;

    Abstract : Graphene, an atomic-thin carbon sheet with carbon atoms tightly packed honeycomb-like lattice, has attracted enormous interest due to its unique chemical and physical properties. However, the intrinsic zero bandgap characteristic of graphene has so far prevented graphene from building effective electronic and optoelectronic devices. READ MORE