RT info:eu-repo/semantics/bachelorThesis
T1 Emisión láser en películas delgadas
A1 Bueno Felipe, Sonia María
K1 Luminiscencia
K1 Emisión
K1 ASE
AB In this work we make an approach to some spectroscopy related concepts such as luminescence, emission spectra, the characteristics of absorption and emission, laser andamplified spontaneous emission. We address specifically the concept of fluorescence asit is the phenomenon in which the current line of investigation of this work is based,starting by giving a theoretical background in some basic aspects and then proceedingto a more detailed study of our state-of-the-art samples, commenting the importance ofeach one of the samples separately and focusing in the optical properties that make themsome of the most important components in the field. These samples are thin film composites with different active layers including the organic polymer poly[2-methoxy-5-(2’-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV), the organic semiconductor 5,6,11,12-Tetraphenyltetracene (rubrene) and organometallic T iO2 perovskites. These materialhave an extensive literature being one of the most popular topics due to their high chargecarrier mobility, astounding growth rates of their efficiencies, advantageous costs of production, among other issues.We set the main objectives: the optical the characterization of the different materials,and the analysis of various types of setups to try to obtain different types of emission likelaser, or amplified spontaneous emission.We show the specifications of the samples of rubrene, perovskites and MEH-PPV;to cover the characteristics of the thin film composites. Then we briefly talk about thedevices used for the optical characterization, mentioning some of their specifications andproceed to show the set ups that we utilized for the absorption, emission, lifetimes, etc.A theoretical background is given for a better comprehension of the results derived fromthe optical characterization.The experimental results are displayed and discussed separately for each one of thematerials. We study thoroughly the processes that take place, highlighting the particular peculiarities of each sample. For the rubrene samples the absorption spectrum wasanalyzed for different samples and their lifetimes were studied according to the diagramlevels of the rubrene. No ASE emission was observed. For the perovskite based sampleswe study the lifetime of compact and porous perovskites, giving also an analysis of theiremission spectra. For the MEH-PPV we start with the absorption and emission spectraof different composites, no laser phenomenon was observed for the samples but narrowemission peaks were observed, showing variable wavelength according to the angle of detection; as well as ASE, whose threshold power was studied for the different composites.All the results were compared with those that can be found in the literature and delveinto the possible causes for ones that do not adjust to what we expect.Finally we sum up the measurements we made and present the conclusions we reachedin this project.
YR 2019
FD 2019
LK http://riull.ull.es/xmlui/handle/915/15731
UL http://riull.ull.es/xmlui/handle/915/15731
LA es
DS Repositorio institucional de la Universidad de La Laguna
RD 27-nov-2024