Search for dissertations about: "nonpolar"

Showing result 1 - 5 of 23 swedish dissertations containing the word nonpolar.

2. 1. Impact of carrier localization on recombination in InGaN quantum wells with nonbasal crystallographic orientations

   Author : Ruslan Ivanov; Saulius Marcinkevičius; Nicolas Grandjean; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; InGaN; quantum well; semipolar; nonpolar; near-field microscopy; carrier localization; carrier transport; optical polarization; Fysik; Physics;

   Abstract : The modern InGaN technology demonstrates high efficiencies only in the blue spectral region and low current operation modes. The growth of InGaN quantum wells (QWs) on nonbasal crystallographic planes (NBP) has potential to deliver high-power blue and green light emitting diodes and lasers. READ MORE

4. 2. Localization effects in ternary nitride semiconductors

   Author : Vytautas Liuolia; Saulius Marcinkevicius; Toshiharu Saiki; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; AlGaN; InGaN; AlInN; LEDs; near-field microscopy; carrier dynamics; alloy fluctuations; carrier localization; built-in electric field; nonpolar planes; polarized luminescence;

   Abstract : InGaN based blue and near-ultraviolet light emitting diodes and laser diodes have been successfully commercialized for many applications such as general lighting, display backlighting and high density optical storage devices. Despite having a comparably high defect density, these devices are known for their efficient operation, which is attributed to localization in potential fluctuations preventing carriers from reaching the centers of nonradiative recombination. READ MORE

5. 3. Semipermeable membrane devices as integrative tools for monitoring nonpolar aromatic compounds in air

   Author : Hanna Söderström; Mats Tysklind; Per-Anders Bergqvist; Jochen F. Muller; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Environmental chemistry; air pollution; alkyl-PAHs; atmosphere; bioavailability; boundary layer; diffusive sampling; emissions; integrative; membrane; monitoring; nitro-PAHs; PAHs; particles; passive samplers; PCBs; plants; PRCs; release rate; sampler design; sources; SPMDs; traffic; uptake rate; wind effect; wood burning; Miljökemi; Environmental chemistry; Miljökemi;

   Abstract : Air pollutants pose a high risk for humans, and the environment, and this pollution is one of the major environmental problems facing modern society. Active air sampling is the technique that has been traditionally used to monitor nonpolar aromatic air pollutants. READ MORE

6. 4. The Effect of Mg Doping on Optical and Structural Properties of GaN

   Author : Sergey Khromov; Galia Pozina; Lars Hultman; Linköpings universitet; []
   Keywords : ;

   Abstract : Mg is the most commonly used p-type dopant for GaN, however the impact of Mg incorporation on structural, morphological and optical properties of GaN is still not fully understood. Another research challenge is to understand and improve the properties of nonpolar GaN as it allows the fabrication of more efficient optoelectronic devices due to the absence of polarization fields. READ MORE

7. 5. Antibacterial elastomeric materials for biomedical applications

   Author : Annija Stepulane; Chalmers tekniska högskola; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hydrogels; antibacterial coating; polydimethylsiloxane; elastomer blends; drug-delivery; antimicrobial peptides;

   Abstract : An ageing population in combination with scientific and clinical advancements have led to a steady increase in the use of medical devices. Elastomeric biomaterials – materials displaying rubber-like mechanics – have found widespread applicability in the production of both short- and long-term medical devices. READ MORE