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Visar resultat 1 - 5 av 9 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Type-II interband quantum dot photodetectors

   Författare :Oscar Gustafsson; Mattias Hammar; Wenquan Ma; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; photodetector; quantum dot; infrared; MOVPE; thermal imaging; type-II; photoluminescence; III V; InSb; InGaSb; InAs; SRA - ICT; SRA - Informations- och kommunikationsteknik;

   Sammanfattning : Photon detectors based on single-crystalline materials are of great interest for high performance imaging applications due to their low noise and fast response. The major detector materials for sensing in the long-wavelength infrared (LWIR) band (8-14 µm) are currently HgCdTe (MCT) and AlGaAs/GaAs quantum wells (QW) used in intraband-based quantum-well infrared photodetectors (QWIPs). LÄS MER

3. 2. Development of Nanoparticle Sensitized Solar Cells

   Författare :Chunze Yuan; Hans Ågren; Anders Hagfeldt; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum dots; quantum rods; nanoparticles; solar cells; colloidal; type-II; electron extraction; alloy; organic electrolyte; energy relay; upconversion.;

   Sammanfattning : In this thesis, I have been working with the development of nanoparticle sensitized solar cells. In the subarea of quantum dot sensitized solar cells (QDSCs), I have investigated type-II quantum dots (QDs), quantum rods (QRs) and alloy QDs, and developed novel redox couples as electrolytes. LÄS MER

4. 3. Spectroscopic studies of III-V semiconductors in two, one and zero dimensions

   Författare :Dan Hessman; Fasta tillståndets fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; InAs-InP; low-dimensional structures; quantum wells; quantum dots; quantum wires; k.p calculations; type-II; photoluminescence; V grooves; Stranski Krastanow; single dot spectroscopy; GaAs-InP; III-V semiconductors; Fysicumarkivet A:1996:Hessman; InAs-GaAs; GaInAs-InP; Halvledarfysik; InP-GaInP; Semiconductory physics;

   Sammanfattning : In this thesis, spectroscopic studies of quantum wells (QWs), quantum wires (QWRs) and quantum dots (QDs) in III-V semiconductors are presented. The electronic structure of these low-dimensional structures have been studied by absorption, photocurrent, electroreflectance, photoluminescence (PL), and photoluminescence excitation (PLE) spectroscopy. LÄS MER

5. 4. The Study of II-VI Semiconductor Nanocrystals Sensitized Solar Cells

   Författare :Chunze Yuan; Ying Fu; Lars Kloo; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum dots; quantum rods; nanocrytals; solar cells; colloidal; type-II; electron injection; organic electrolyte.;

   Sammanfattning : Semiconductor nanocrystals, also referred to as quantum dots (QDs), have been the focus of great scientific and technological efforts in solar cells, as a result of their advantages of low-cost, photostability, high molar extinction coefficients and size-dependent optical properties. Due to the multi-electron generation effect, the theoretically maximum efficiency of quantum dots-sensitized solar cells (QDSCs) is as high as 44%, which is much higher than that of dye-sensitized solar cells (DSCs). LÄS MER

7. 5. Fabrication and Photoelectrochemical Applications of II-VI Semiconductor Nanomaterials

   Författare :Abhilash Sugunan; Muhammet Toprak; Mamoun Muhammed; Gerrit Boschloo; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ZnO; nanowire arrays; photocatalysis; CdTe; CdSe; CdS; nanotetrapods; nanotetrahedrons; photoconduction; nano-gap electrodes; Type-II QDs; P3HT nanofibers; microwave synthesis.;

   Sammanfattning : In this work we investigated fabrication of semiconductor nanomaterials and evaluated their potential for photo-chemical and photovoltaic applications. We investigated different II-VI semiconductor nanomaterial systems; (i) ZnO oriented nanowire arrays non-epitaxially grown from a substrate; and (ii) colloidal CdE (E=Te,Se,S) quantum structures synthesized by solution-based thermal decomposition of organo-metallic precursors. LÄS MER