Licentiate
ThesisElectronic characterization of molecules with application to organic
light emitting diodesEmil Jansson AbstractThe presented
thesis is devoted to the field of organic light emitting diodes (OLEDs). Kohn-Sham
density functional theory (DFT) is applied in order to eludicate optical properties
such as fluorescence and phosphorescence for some of the most important materials.
The accuracy of DFT is evaluated with respect to the calculated absorption and
emission spectra for commonly used light emitting polymers.
A continuation
of this work is devoted to Polyfluorene as this polymer has proven very promising.
In this study the chain length dependence of its singlet and triplet excited states
is analyzed as well as the excited state structures. Understanding the phosphorescence
mechanism of tris(2-phenylpyridine)Iridium is of importance in order to interpret
the high efficiency of the OLEDs containing these specimen. The mechanism is analyzed
by calculating the electric dipole moments by means of time-dependent DFT using
quadratic response functions.
As not only the optical properties are essential
for a effective devices, electron transfer properties are addressed. The electron
transfer capability of the sulfur and nitrogen analogues of Oxadiazole is evaluated
through their internal reorganization energy. Stockholm 2007, ISBN 978-91-7178-623-4 | 
