Search for dissertations about: "semiconductors"

Showing result 16 - 20 of 326 swedish dissertations containing the word semiconductors.

  2. 16. Semiconductor Quantum Dots Studied by Time-Resolved Luminescence Techniques

    Author : Jörg Siegert; KTH; []
    Keywords : quantum dots; semiconductors; photoluminescence; time-resolved;

    Abstract : In this thesis time-resolved photoluminescence spectroscopyis presented as a powerful tool to study the carrier dynamicsin various self-assembled quantum dot (QD) structures, whichare potentially attractive for device applications. The experiments reveal the impact of proton irradiation onInGaAs QDs and comparable quantum wells. READ MORE

  4. 17. Designing and Tuning the Properties of Materials by Quantum Mechanical Calculations

    Author : Jailton Souza de Almeida; Rajeev Ahuja; Patrizia Monachesi; Uppsala universitet; []
    Keywords : Physics; Density Functional Theory; Electronic Structure; Phase Transitions; High Pressure; Optical Properties; Dielectric Functions; Semiconductors; Metals; Fysik;

    Abstract : In many materials, changes in chemical composition, pressure or temperature can induce metal to insulator transitions. It is recently observed in yttrium hydride, for example, changes from a shiny mirror (YH2) to a transparent window (YH3), which has important technological application in optical devices. READ MORE

  5. 18. Defects in Bismuth Vanadate: Insights from First Principles

    Author : Nicklas Österbacka; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; defects; oxides; semiconductors; density functional theory;

    Abstract : Photoelectrochemical water splitting is an attractive technique for sustainable hydrogen production, but its efficiency is heavily dependent on the properties of the semiconducting photoelectrodes used in the process. These properties are intimately connected to the presence of point defects in the materials, and understanding this relationship is a key step towards the development of better photoabsorbers. READ MORE

  6. 19. Fabrication of Low-Dimensional Structures in III-V Semiconductors

    Author : Ivan Maximov; Fasta tillståndets fysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; III-V semiconductors; plasma; etching; aerosol; lithography; quantum dots; quantum well wires; quantum point contact; damage; luminescence; Fysicumarkivet A:1997:Maximov; Halvledarfysik; Semiconductory physics;

    Abstract : The thesis presents studies on the processing technology and the characterization of nanometer-sized and low-dimensional structures in III-V semiconductors. Two major approaches are described: 1) the combination of aerosol technology and plasma etching for the fabrication of quantum dots (QDs) in InP-based materials and 2) the use of high-resolution electron beam lithography and plasma or wet chemical etching to make quantum well wires (QWWs) in both GaAs and InP-based structures. READ MORE

  7. 20. Optical Studies of InAs Quantum Dots in III-V Semiconductors

    Author : Lars Landin; Fasta tillståndets fysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; quantum dots; III-V semiconductors; k.p calculations; photoluminescence; deep-level transient spectroscopy; photoconductivity; few particle effect; single dot spectroscopy; InAs InP; Semiconductory physics; Halvledarfysik; Fysicumarkivet A:2000:Landin; InAs GaAs;

    Abstract : I this thesis, optical studies of InAs quantum dots (QDs) in GaAs and InP are presented. The electronic structure of these zero dimensional structures, grown in the Stranski-Krastanow growth mode, was studied by photoluminescence spectroscopy (PL), junction space-charge techniques (JSCT) and photoconductivity (PC) measurements. READ MORE