Sökning: "electron-hole recombination"

Visar resultat 1 - 5 av 16 avhandlingar innehållade orden electron-hole recombination.

1. 1. On Generation and Recombination in Cu(In,Ga)Se2 Thin-Film Solar Cells

   Författare :Jonas Malmström; Lars Stolt; Uwe Rau; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electronics; solar energy conversion; solar cells; Cu In; Ga Se2; device modelling; optical properties; electron-hole generation; light trapping; electron-hole recombination; Elektronik; Electronics; Elektronik;

   Sammanfattning : The solar cell technology based on Cu(In,Ga)Se2 (CIGS) thin-films provides a promising route to cost competitive solar electricity. The standard device structure is ZnO:Al/ZnO/CdS/CIGS/Mo films on a glass substrate, where the first three layers are n-type semiconductors with wide bandgaps, forming a pn-junction with the p-type CIGS absorber layer; the Mo layer serves as a back contact. LÄS MER

3. 2. Dynamics of Excitation Transfer and Charge Separation in Polymeric Semiconductors

   Författare :Arvydas Ruseckas; Kemisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Anisotropy; Photoinduced absorption; Femtosecond spectroscopy; Polythiophene; Conjugated polymers; Donor-Acceptor Complexes; Carbazole; Charge separation; Excitation transfer; Recombination; Physics; Fysik;

   Sammanfattning : Dynamics of optically excited electronic states have been studied in solid films and solutions of semiconducting polymers and model compounds. Transient absorption, monitored in the spectral range from 0.9 eV to 2.5 eV with a time resolution of about 100 fs, was the main experimental technique. LÄS MER

4. 3. Development of Graphitic Carbon Nitride based Semiconductor Photocatalysts for Organic Pollutant Degradation

   Författare :Jing Wang; Pär Jönsson; Anders Palmqvist; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; graphitic carbon nitride; visible light-driven photocatalyst; staggered band alignment; electron-hole pair separation; band edge position; Materials Science and Engineering; Teknisk materialvetenskap;

   Sammanfattning : As a potential solution to the global energy and environmental pollution, design and synthesis of artificial photocatalysts with high activities have attracted increasing scientific interests worldwide. In recent years, the graphitic carbon nitride (g-C3N4) has shown new possible applications in the photocatalytic field due to its unique properties. LÄS MER

5. 4. Microscopic Mechanisms of the Formation, Relaxation and Recombination of Excitons in Two-Dimensional Semiconductors

   Författare :Samuel Brem; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; relaxation dynamics; 2D materials; density matrix formalism; excitons; exciton-phonon interaction; Bloch equations;

   Sammanfattning : Monolayers of Transition Metal Dichalcogenides (TMDs) present a giant leap forward towards the realization of semiconductor devices with atomic scale thickness. As a natural consequence of their two-dimensional character TMDs exhibit a reduced dielectric screening, leading to the formation of unusually stable excitons, i.e. LÄS MER

7. 5. Quantum Theory of Exciton-Exciton Interactions in Atomically Thin Semiconductors

   Författare :Daniel Erkensten; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; excitons; transition-metal dichalcogenides; many-body theory; van der Waals heterostructures; 2D materials;

   Sammanfattning : Atomically thin materials such as transition-metal dichalcogenides (TMDs) have emerged as an unprecedented platform for engineering future optoelectronic devices and studying exotic quantum phases of matter. In particular, the strong Coulomb interaction in these materials enables the formation of tightly-bound excitons, electron-hole pairs with neither purely fermionic nor bosonic character. LÄS MER