Sökning: "Semiconductor physics"

Visar resultat 16 - 20 av 310 avhandlingar innehållade orden Semiconductor physics.

  1. 16. Charged particle distributions and robustness of the neural network pixel clustering in ATLAS

    Författare :Edvin Sidebo; Jonas Strandberg; Bengt Lund-Jensen; David Silvermyr; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; p p: scattering; ATLAS; LHC; charged particle: multiplicity; semiconductor detector: pixel; neural network: performance; track data analysis: cluster; charged particle: cluster; splitting; CERN LHC Coll; Fysik; Physics;

    Sammanfattning : This thesis contains a study of the robustness of the artificial neural network used in the ATLAS track reconstruction algorithm as a tool to recover tracks in dense environments. Different variations, motivated by potential discrepancies between data and simulation, are performed to the neural network’s input while monitoring the corresponding change in the output. LÄS MER

  2. 17. Resonant Tunneling in Laterally Confined Quantum Structures

    Författare :Boel Gustafson; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; gravitation; relativity; quantum mechanics; classical mechanics; Mathematical and general theoretical physics; Fysik; Physics; High peak-to-valley ratio; Lateral confinement; Quantum dots; Resonant tunneling; Self-assembled quantum dots; Schottky depletion; Buried metal gate; Electron transport; Magnetic-field dependence; Energy level width; Tunneling transistors; Mode coupling; statistical physics; thermodynamics; Matematisk och allmän teoretisk fysik; klassisk mekanik; kvantmekanik; relativitet; statistisk fysik; termodynamik; Technological sciences; Teknik; Fysicumarkivet A:2001:Gustafson;

    Sammanfattning : In the thesis, three-dimensionally confined resonant tunneling structures were studied experimentally. Two approaches were used for obtaining quantum confinement: gate-defined lateral constriction of double barrier structures, and epitaxial growth of self-assembled quantum dots. LÄS MER

  3. 18. Effect of Substrate on Bottom-Up Fabrication and Electronic Properties of Graphene Nanoribbons

    Författare :Konstantin Simonov; Olof Karis; Nils Mårtensson; Alexei Preobrajenski; Alessandro Baraldi; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; graphene nanoribbons; bottom-up; substrate; metal contact; electronic structure; electron doping; PES; ARPES; NEXAFS; STM; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : Taking into account the technological demand for the controlled preparation of atomically precise graphene nanoribbons (GNRs) with well-defined properties, the present thesis is focused on the investigation of the role of the underlying metal substrate in the process of building GNRs using bottom-up strategy and on the changes in the electronic structure of GNRs induced by the GNR-metal interaction. The combination of surface sensitive synchrotron-radiation-based spectroscopic techniques and scanning tunneling microscopy with in situ sample preparation allowed to trace evolution of the structural and electronic properties of the investigated systems. LÄS MER

  4. 19. Three-Dimensional Metal-Semiconductor Heterostructures for Device Applications

    Författare :Lars-Erik Wernersson; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Schottky contacts; space-charge spectroscopy; ballistic transport; Coulomb repulsion; electron interference; resonant tunnelling; lateral confinement; heterojunction permeable base transistor; resonant tunnelling diodes; Fysicumarkivet A:1998:Wernersson; Fysik; Physics; resonant tun; epitaxial overgrowth;

    Sammanfattning : Fabrication and characterisation of buried metal contacts in compound semiconductors are demonstrated. The contacts have been investigated due to their usage both as gates in transistors and as active or passive elements in novel devices. LÄS MER

  5. 20. Initial stages of metal- and organic-semiconductor interface formation

    Författare :Pål Palmgren; Mats Göthelid; Mikael Grehk; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Semiconductor physics; Halvledarfysik;

    Sammanfattning : This licentiate thesis deals with the electronic and geometrical properties of metal-semiconductor and organic-semiconductor interfaces investigated by photoelectron spectroscopy and scanning tunneling microscopy. First in line is the Co-InAs interface (metal-semiconductor) where it is found that Co is reactive and upon adsorption and thermal treatment it alloys with the indium of the substrate to form metallic islands, about 20 nm in diameter. LÄS MER