Sumários

paper reading

13 Dezembro 2022, 16:30 • Maria Margarida Cruz

Due to weather conditions, the did not allowed displacement to the University, this class was converted in paper reading and discussion.

T - Optical properties of nanoparticles

13 Dezembro 2022, 14:00 • Maria Margarida Cruz

Optical properties of materials. Plasma frequency. Dielectric constant as a function of frequency. Dielectric constant of metallic nanoparticles. Clausius-Mossotti relationship. Surface plasmon. Metallic nanoparticles with diameters smaller than 20 nm. Quantum effects: redshift and resonance broadening.

Optical properties of semiconductors. Direct and indirect gap. Optical properties of semiconductor nanoparticles. Exciton binding energy versus confinement. Semiconductor laser.

Applications of nanoparticles.

Problems 9

6 Dezembro 2022, 16:30 • Maria Margarida Cruz

Discussion of problems in 9th series.

T11 - Nanoparticles and nanostructures

6 Dezembro 2022, 14:00 • Maria Margarida Cruz

"Quantum dots" - Stability diagram showing "magic numbers". Comparison with results in metallic aggregates. Application of the Jellium model for the calculation of electronic states. Behavior of small aggregates as "giant atoms". Nanoparticles: importance of surface contribution, thermodynamic properties. Crystalline metallic nanoparticles in thermodynamic equilibrium: Wulf polyhedron. Nanoparticles with directional bonds. Cage aggregates. The carbon allotropes. Fullerenes. Carbon nanotubes. Single-walled and multi-walled nanotubes. Winding vector and electronic structure. Relationship with physical properties.

Problems 8

29 Novembro 2022, 16:30 • Maria Margarida Cruz

Discussion of problems in 8th series. Evaluation question.