Nanocrystals for resonance energy transfer and lasing applications

The work at hand is structured into four chapters, the first of which is this introduction. An appendix explains a small experiment on a different topic of research that differs from the core of this thesis.The second chapter explains the physics of semiconductor crystals and semiconductor nanostructures. Introduces the mathematical framework to describe the exciton in semiconductor nanostructures.Chapter three outlines the mechanism of RET and is dedicated to the experimental and theoretical methods we employed during our research. We present the technique that has allowed us to perform a RET distance dependence study, the AFM equipment, the laser system and time resolved spectroscopic techniques that allowed us to investigate the exciton structure and dynamics in our material system and our results.Chapter four shows the theoretical background, the experimental methods and equipment we used to archive lasing with NCs. The theory of whispering gallery modes and photonic crystal is explained and we describe how, using NCs, silica microsphere resonator and PC nanocavity, we achieved lasing regime in both configurations.The appendix shows an evanescence field spectroscopy experiment in which tapered fibers and golden nanoparticles have been used to realize an extremely sensitive device based on evanescence spectroscopy