Μελέτη μορφολογίας στερεών υμενίων για φωτονιοενεργειακή αναβάθμιση

Abstract

This thesis investigates the link between the morphology of polymeric material systems and the phenomenon of photon up-conversion. “Photon up-conversion” constitutes a property of substances to emit light in smaller wavelengths compared to the wavelength they tend to absorb. Subsequently, the energy they absorb is lower than then energy they emit. During this thesis, the researcher prepared solutions with various compositions which deposited in order to form the desired films. Spin coating was used for the process of deposition. At a later stage, the films were investigated using Atomic Force Microscopy (AFM), Ultraviolet-visible (UV-vis) Spectroscopy and Scanning Electron Microscopy (SEM). Furthermore, at the beginning of the experimental process certain films were formed whose solutions had a different composition. The films were formed through depositing solutions with stable composition but variable solvent. The experiment indicated that the roughness and generally the morphology of the surface of the film prepared by a binary mixture solution PFO:PtOEP is influenced by the temperature. Moreover, the absorption spectra gathered using UV-Vis showed that the existence of octaethylporphyrin (PtOEP) boosts the formation of β-phase of polyfluorene (PFO). The experimental work was undertaken at the «Device Technology and Chemical Physics» laboratory where the films were deposited along with the UV-vis spectroscopic characterization and at the «Nano/Micro Mechanics of Materials Laboratory» where the AFM was performed. The departmental SEM facility was used.