Sökning: "electron mobility"

Visar resultat 16 - 20 av 189 avhandlingar innehållade orden electron mobility.

  1. 16. Cryogenic InP High Electron Mobility Transistors in a Magnetic Field

    Författare :Isabel Harrysson Rodrigues; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; magnetic field; cryogenic; low noise amplifier; angular dependence; InP HEMT; geometrical magnetoresistance;

    Sammanfattning : The InGaAs-InAlAs-InP high electron mobility transistor (InP HEMT) is the preferred active device used in a cryogenic low noise amplifier (LNA) for sensitive detection of microwave signals. In this thesis it is demonstrated that the InP HEMT, when placed in a magnetic field, has a strong angular dependence in its output current. LÄS MER

  3. 17. InP High Electron Mobility Transistor Design for Cryogenic Low Noise Amplifiers

    Författare :Eunjung Cha; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cryogenic; stability; noise temperature; InP HEMT; LNA; MMIC;

    Sammanfattning : The InGaAs/InAlAs/InP high electron mobility transistor (InP HEMT) is the superior technology for the most demanding low-noise and high-speed microwave and millimeter-wave applications, in particular in radio astronomy and deep-space communication. InP HEMT has enabled cryogenic low noise amplifier (LNA) designs with noise temperatures about ten times the quantum noise limit from sub  GHz up to 120 GHz. LÄS MER

  4. 18. Growth and characterization of SiC and GaN

    Författare :Rafal Ciechonski; Erik Janzén; Sebastian Lourdudoss; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SiC; GaN; Deep level transient spectroscopy; Minority Carrier Transient Spectroscopy; Hall effect; Cathodoluminescence; Scanning electron microscopy; Atomic Force microscopy; sublimation growth; MOCVD; heterostructures; High Electron Mobility transistor; point defects; Material physics with surface physics; Materialfysik med ytfysik;

    Sammanfattning : At present, focus of the SiC crystal growth development is on improving the crystalline quality without polytype inclusions, micropipes and the occurrence of extended defects. The purity of the grown material, as well as intentional doping must be well controlled and the processes understood. LÄS MER

  5. 19. Valley-Polarized Charge Transport in Diamond

    Författare :Nattakarn Suntornwipat; Jan Isberg; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CVD diamond; valleytronics; Negative Differential Mobility; NDM; electron polarization; Time-of-Flight; ToF; magnetotransport; carrier transport; drift velocity; Teknisk fysik med inriktning mot materialvetenskap; Engineering Science with specialization in Materials Science;

    Sammanfattning : Diamond is a wide bandgap semiconductor with extreme properties such as high thermal conductivity, high breakdown field and high carrier mobilities. These properties together with the possibility to synthesize high purity Single-Crystalline (SC) diamond by Chemical Vapor Deposition (CVD), makes it a really interesting material for electronic devices. LÄS MER

  7. 20. 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