Sökning: "polarons"

Visar resultat 11 - 15 av 15 avhandlingar innehållade ordet polarons.

1. 11. Theoretical Studies on Electronic Structure, Spectra and Conductivity of Pristine and Alkali Doped Polyacetylene

   Författare :Lucía Mercedes Rodrigues Monge; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; theoretical calculations; electron transfer; conductivity; polyacetylene; alkali metal; ab-initio methods; charge transport; semiempirical methods; doping;

   Sammanfattning : The present thesis is a theoretical investigation of the electronic properties of linear polyenes to get an insight into conductive phenomena in pristine and doped polyacetylene. Conductivity in polyacetylene is a complex phenomena and cannot be treated within simple band models. LÄS MER

3. 12. Chemical and electronic structure of interfaces in organic-based devices

   Författare :Annica Crispin; Henrik Stubb; Linköpings universitet; []
   Nyckelord :;

   Sammanfattning : This thesis deals with some of the main physical and chemical phenomena involving organic semiconductors in (opto )electronic devices: (i) the fabrication and characteristics of organic light emitting diodes (OLEDs), (ii) the chemistry occurring at metal-polymer and polymer-metal interfaces, (iii) the nature of electronic levels induced upon doping in molecular organic semiconductors.In the first paper, fluorine tin oxide (FTO) electrodes have been studied as an alternative to indium tin oxide (ITO) for hole-injection in polymer-based light emitting devices. LÄS MER

4. 13. Defect Thermodynamics and Kinetics in Polyanionic Cathodes : A Theoretical Roadmap for Na-ion based Batteries and Hybrid Supercapacitors

   Författare :Teeraphat Watcharatharapong; Rajeev Ahuja; Sudip Chakraborty; Jan Isberg; Palani Balaya; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; DFT; Energy Materials; Defects; Chemical potentials; Kinetics; Hybrid supercapacitors; Na-ion batteries; Polyanionic cathodes;

   Sammanfattning : In this thesis, the framework of the density functional theory is employed to study and predict properties of polyanionic cathodes for Na-ion batteries and hybrid supercapacitors. It consists of three main parts as follows:The first part is primarily dedicated to kröhnkite-type Na2Fe(SO4)22H2O cathode. LÄS MER

5. 14. Magnetotransport Studies of Mn Ion-Implanted Nanowires

   Författare :Waldomiro Paschoal; Linnaeus University; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; hopping conduction; ferromagnetism; ion-implantation; Nanowire; GaMnAs; magnetoresistance; Fysicumarkivet A:2014:Paschoal;

   Sammanfattning : This thesis focuses on the magnetotransport properties of highly Mn-doped crystalline GaAs nanowires. The GaAs nanowires were first grown by metal-organic vapor phase epitaxy from gold seed particles, and subsequently implanted with Mn ions under varying conditions, e.g., ion fluence and acceleration voltage. LÄS MER

7. 15. Electron-lattice dynamics in π-conjugated systems

   Författare :Magnus Hultell (Andersson); Sven Stafström; Alessandro Troisi; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; charge transport; electron-lattice dynamics; polaron; adiabatic transport; electron localization; internal conversion; Computational physics; Beräkningsfysik;

   Sammanfattning : The work presented in this thesis concerns the dynamics in π-conjugated hydrocarbon systems. Due to the molecular bonding structure of these systems there exists a coupling between the electronic system and the phonons of the lattice. LÄS MER