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Visar resultat 1 - 5 av 23 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Novel Terahertz Emitters and Detectors: InGaAs Slot Diodes and InAs Self-Switching Diodes

    Författare :Andreas Westlund; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; InAs; InGaAs; slot diode; self-switching diode; zero-bias diode;

    Sammanfattning : Two novel types of diodes for emission and detection of THz radiation have been investigated. The diodes are based on high electron mobility III-V heterostructures. Both diodes are aimed for room-temperature operation, for which there is a demand for new THz technology. For emission, slot diodes based on an InGaAs heterostructure were studied. LÄS MER

  3. 2. Scaling of InGaAs/InAlAs and InAs/AlSb HEMTs for microwave/mm-wave applications

    Författare :Malin Borg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; metamorphic; InGaAs; gate length; pseudomorphic; InAs; AlSb; InP; Schottky layer; High electron mobility transistor HEMT ; drain bias;

    Sammanfattning : The InGaAs/InAlAs high electron mobility transistor (HEMT) offers the highest maximum frequency of oscillation fmax and the lowest noise performance (NFmin) for microwave/mm-wave receivers. Similar to other device technologies, the performance of the InGaAs/InAlAs HEMT has gradually been improved by device scaling. LÄS MER

  4. 3. Photoelectron Spectroscopy Studies of III-V Semiconductor Systems

    Författare :Henric Åsklund; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; low temperature MBE; GaAs 111 A; InAs; core-level; GaMnAs; photoelectron spectroscopy; MEE; GaAs; InP 110 :As; valence-band; core-exciton; diluted magnetic semiconductor; MBE; interface; III-V semiconductor; surface; InAs 111 A; thin films;

    Sammanfattning : Photoelectron spectroscopy has been used as a main tool to study a number of III-V semiconductor surfaces. This thesis includes studies of a surface reaction, As/InP(110), thin heteroepitaxial layers, InAs on GaAs(111)A and GaAs on AlAs(100), and a diluted magnetic semiconductor, Ga1-xMnxAs. LÄS MER

  5. 4. InAs/AlSb HEMTs for Cryogenic Low-Noise Applications

    Författare :Giuseppe Moschetti; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cryogenic; metamorphic; high frequency; high electron mobility transistor HEMT ; low power; low noise.; InAs AlSb;

    Sammanfattning : The InAs/AlSb high electron mobility transistor (HEMT) is an emerging microwave device technology. The high electron mobility and high peak electron velocity of the InAs channel makes this device technology a potential candidate for low-noise applications operating at very low power dissipation. LÄS MER

  7. 5. Self-Switching Diodes for Zero-Bias Terahertz Detection

    Författare :Andreas Westlund; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; self-switching diode; noise-equivalent power; SSD; graphene; zero-bias; InAs; InGaAs; terahertz; detector;

    Sammanfattning : The self-switching diode (SSD) has been investigated as a potential terahertz detector in recent years. The SSD accomplishes a non-linear current-voltage relation through a field-effect, which enables detection at zero bias from microwave up to terahertz frequencies. In this work, SSDs were realised in two new materials; InAs and graphene. LÄS MER