Sökning: "electron tunnelling"

Visar resultat 1 - 5 av 34 avhandlingar innehållade orden electron tunnelling.

1. 1. 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

3. 2. Scanning Tunnelling Microscopy and Spectroscopy of Adsorbates on Aluminium and Silicon

   Författare :Mikael Johansson; Synkrotronljusfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Alkali metals; Scanning tunnelling spectroscopies; Scanning tunnelling microscopy; Photoelectron Spectroscopy; Single crystal surface; Silicon; Surface structure; Aluminium; Silicides; Fullerenes.; Physics; Fysik; Fysicumarkivet A:1997:Johansson;

   Sammanfattning : The main topic of this thesis is the investigation of atomic andmolecular adsorbates on single crystal surfaces of silicon and aluminiumusing the techniques of scanning tunnelling microscopy (STM) andspectroscopy (STS). The emphasis has been to use atomic-resolutionspectroscopy and imaging to determine the relationship between thesurfaces' geometric and electronic structures. LÄS MER

4. 3. Time-resolved detection of temporally correlated, single-charge tunnelling

   Författare :Jonas Bylander; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Josephson junctions; time-correlated tunnelling; radio-frequency single-electron transistor; current standard; charge solitons; SET oscillations; Coulomb blockade; metrology; SET; tunnel junction array;

   Sammanfattning : We report real-time detection of the single charges that constitute a small electrical current, as they flow through a nano-electronic device. This represents a direct demonstration of charge discreteness in an electrical current. LÄS MER

5. 4. Time dependent material properties of shotcrete for hard rock tunnelling

   Författare :Lars Elof Bryne; Anders Ansell; Wolfgang Kusterle; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Shotcrete; rock; granite; bond strength; compressive strength; pullout testing; failure modes; interfacial transition zone; micro structure; ettringite; set accelerator; shrinkage; drains; glass fibres; laboratory testing; tunnels tunnelling;

   Sammanfattning : In this thesis different mechanical properties for shotcrete (sprayed concrete) such as compression strength, bond strength, bending tensile strength, elastic modulus, free and restrained shrinkage as a function of its age was investigated. One of the main issues was to investigate the difference between ordinary cast concrete and shotcrete. LÄS MER

7. 5. Electrical Properties of Carbon Black Polymer Composites: Filler Particle Rearrangement

   Författare :Karl Michael Jäger; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; conductivity; fractal; permittivity; carbon black; dielectric; electron tunnelling; polymer; image analysis; cluster; percolation;

   Sammanfattning : The practical application of semi-conducting carbon black polymer composites often involves temperature variations resulting in changes in their electrical properties. Study of cross-linked ethylene butylacrylate copolymer (EBA) filled with acetylene black has shown that these changes are due to carbon black network re-arrangement. LÄS MER