Avancerad sökning

Visar resultat 1 - 5 av 65 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Molecular beam epitaxy growth and characterization of GaN, AlN and AlGaN/GaN heterostructures

    Författare :Stefan Davidsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; two-dimensional electron gas; MBE; Al2< sub>O3< sub>; epitaxial growth; III-nitride; molecular beam epitaxy; GaN; nucleation layer; nitridation; AlGaN; HFET; 2DEG density; AlN; 2DEG; buffer layer; sapphire; 2DEG mobility; heterostructure field effect transistor;

    Sammanfattning : The III-nitride materials, consisting of Al, Ga, In and N, have several physical properties that make them attractive for semiconductor devices in electronic and optic applications. A wide range of direct energy bandgaps (0.7 eV - 6.1 eV) can be obtained. LÄS MER

  3. 2. YBa2Cu3O7-δ Biepitaxial and Step Edge Josephson Junctions on MgO Substrates. SQUID Amplifier

    Författare :Jaime Ramos; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; step edge junction; noise; biepitaxial junction; energy resolution; high-TC superconductor; dc SQUID; YBa2Cu3O7; laser deposition; CeO2; amplifier; Germany; sapphire; MgO;

    Sammanfattning : This thesis concerns the preparation of Josephson junctions and their applications in Superconducting Quantum Interference Devices (SQUIDs). High temperature superconductors were used for operation at 77 K, the boiling temperature of liquid nitrogen. LÄS MER

  4. 3. GaN/AlN Multiple Quantum Well Structures

    Författare :Xinju Liu; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; GaN; AlN; multiple quantum well; Molecular beam epitaxy; Si 111 ; intersubband transition; sapphire; GaN template;

    Sammanfattning : The III-nitride semiconductors: InN, GaN and AlN are promising for photonic, high power and high temperature electronic devices. Their large and direct band gaps cover the range 0.7 to 6.2 eV, i. LÄS MER

  5. 4. Continuous Fibre Reinforced Oxide/Oxide Composites

    Författare :Magnus Holmquist; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polycrystalline oxide fibre; zirconia; single crystal oxide fibre; hot isostatic pressing; hot pressing; alumina; mullite; sapphire; tape casting; interface; VibroIntrusion; interphase; continuous fibre reinforced ceramic composite; mechanical properties; oxide fibre; ceramic matrix composite;

    Sammanfattning : The appealing properties of ceramics include retention of strength and hardness at high temperatures, chemical inertness and low density. However, monolithic ceramics fail in a brittle, unpredictable manner making them unsuitable for many applications where reliability is a key requirement. LÄS MER

  7. 5. Thin films and optical detectors made of YBa2Cu3O7-x

    Författare :Martin Danerud; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; BaF2< sub>; YBa2< sub>Cu3< sub>O7-x< sub>; ECR; bolometric; annealing; sapphire; SrTiO3< sub> 100 ; optical detectors; coevaporation; c-axis orientation; in situ;

    Sammanfattning : .... LÄS MER