Sökning: "Bandgap"

Visar resultat 6 - 10 av 191 avhandlingar innehållade ordet Bandgap.

  1. 6. Periodic structures and lumped elements in microwave passives

    Författare :Dan Kuylenstierna; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Passive elements; Lumped elements; Photonic bandgap; Metamaterial; MMIC; Electromagnetic bandgap; Ferroelectric; Quadrature hybrid; Quadrature power splitter; Balun; Periodic structures;

    Sammanfattning : The ambition of this work is the incorporation of ferroelectric varactors as tuneable elements in Si integrated circuits (ICs). This thesis presents partialfulfillments of the work. LÄS MER

  3. 7. Chemical Structure and Physical Properties of Organic-Inorganic Metal Halide Materials for Solid State Solar Cells

    Författare :Majid Safdari; James M. Gardner; Timothy Kelly; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Perovskite; Solar cells; Organic-inorganic lead halide; Dimensionality; Bandgap; X-ray diffraction; X-ray spectroscopy.; Kemi; Chemistry;

    Sammanfattning : AbstractMethylammonium lead (II) iodide has recently attracted considerable interest which may lead to substantial developments of efficient and inexpensive industrial photovoltaics. The application of this material as a light-absorbing layer in solid-state solar cells leads to impressive efficiency of over 22% in laboratory devices. LÄS MER

  4. 8. Wide Bandgap Semiconductor (SiC & GaN) Power Amplifiers in Different Classes

    Författare :Sher Azam; Qamar Wahab; Jörgen Olsson; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wide bandgap; SiC; MESFET; GaN; HEMT; Power Amplifiers; Materials science; Teknisk materialvetenskap;

    Sammanfattning : SiC MESFETs and GaN HEMTs have an enormous potential in high-power amplifiers at microwave frequencies due to their wide bandgap features of high electric breakdown field strength, high electron saturation velocity and high operating temperature. The high power density combined with the comparably high impedance attainable by these devices also offers new possibilities for wideband power microwave systems. LÄS MER

  5. 9. Computational methods for the analysis and design of photonic bandgap structures

    Författare :Min Qiu; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Photonic crystal; Photonic bandgap; Numerical analysis; Optimal design; Finite-difference time-domain method; Plane wave expansion method; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

    Sammanfattning : In the present thesis, computational methods for theanalysis and design of photonic bandgap structure areconsidered. Many numerical methods have been used to study suchstructures. Among them, the plane wave expansion method is veryoften used. LÄS MER

  7. 10. Electrochemical and electronic devices based on low bandgap polymers

    Författare :Miaoxiang Chen; Qibing Pei; Linköpings universitet; []
    Nyckelord :TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : The research field of the organic electronics includes light emitting diodes (OLEDs), field-effect transistors (OFETs), polymer photovoltaic cells (PVCs), polymer lasers and electrochemical devices. Recently, organic materials are envisaged for spintronics. LÄS MER