Sökning: "color centers"

Visar resultat 1 - 5 av 13 avhandlingar innehållade orden color centers.

1. 1. Color Centers in Semiconductors for Quantum Applications : A High-Throughput Search of Point Defects in SiC

   Författare :Joel Davidsson; Igor A. Abrikosov; Rickard Armiento; Viktor Ivády; Giulia Galli; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; point defects; color centers; high-throughput; photoluminescence; zero phonon line; SiC;

   Sammanfattning : Point defects in semiconductors have been and will continue to be relevant for applications. Shallow defects realize transistors, which power the modern age of information, and in the not-too-distant future, deep-level defects could provide the foundation for a revolution in quantum information processing. LÄS MER

3. 2. Properties of Volume Bragg Gratings and Nonlinear Crystals for Laser Engineering

   Författare :Staffan Tjörnhammar; Fredrik Laurell; Valdas Pasiskevicius; Takunori Taira; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; volume Bragg grating; VBG; thermal effects; nonlinear optics; KTiOPO4; quasi-phase matching; photochromic damage; grey-tracking; color centers; blue-light induced infrared absorption; BLIIRA; Physics; Fysik;

   Sammanfattning : This thesis focuses on two topics: thermal limitations of volume Bragg gratings (VBGs) employed as laser-cavity mirrors and formation of color centers in KTiOPO4 and its isomorphs.To explore the mechanisms of the thermal limitations of VBGs in high power lasers, I designed and constructed a diode-pumped, solid‑state laser with a VBG as cavity mirror that had a significantly higher absorption than what is typical. LÄS MER

4. 3. Optical properties of point defects in insulators and of transition metal dichalcogenides

   Författare :Christopher Linderälv; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; luminescence quenching; charge transition levels; excitons; transition metal dichalcogenides; monolayer alloys; solid state lighting; color centers; oxygen vacancies; moiré structures; wide band gap oxides;

   Sammanfattning : There is a need for new or modified materials, both to improve current devices and to create novel functionalities. Engineering materials to target specific functionalities requires a better understanding of how microscopic processes impact materials properties. LÄS MER

5. 4. Optical properties of GaN and InGaN studied by time- and spatially-resolved spectroscopy

   Författare :Tomas Uždavinys; Saulius Marcinkevičius; Audrius Alkauskas; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Gallium nitride; InGaN; near-field microscopy; photoexcited carrier dynamics; intervalley energy; Fe centers; In incorporation; Physics; Fysik;

   Sammanfattning : The past decade has seen rapid expansion in the use of group III-nitride based devices. White InGaN LEDs are substituting incandescent light bulbs, space satellite industry adopting ion-radiation-resistant GaN transistors, and AlGaN deep UV LEDs are increasingly being used for water disinfection and air purification. LÄS MER

7. 5. Dynamic and quasi-stationary electrochromic response of amorphous tungsten oxide thin films : In situ combined electrochemical and optical measurements during lithium intercalation

   Författare :Edgar Alonso Rojas González; Gunnar Niklasson; Aline Rougier; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Electrochromism; Optical absorption; Amorphous materials; Tungsten oxide; Electrochemical impedance spectroscopy; Color impedance spectroscopy; Intercalation; Engineering Science with specialization in Solid State Physics; Teknisk fysik med inriktning mot fasta tillståndets fysik;

   Sammanfattning : Electrochromic (EC) materials can adjust their optical properties, reversibly, by means of an external electrical stimulus. They have relevant technological applications; for example, energy-efficient smart windows, which can adapt dynamically—according to the given environmental conditions—to control the heat and visible light fluxes between the interior and exterior of a building. LÄS MER