Jan Pecka

Organic light-emitting devices based on novel blends

Photoluminescence (PL), electroluminescence (EL) and degradation of a soluble electroluminescent poly(p- phenylene), SPPP,. And its blends with hole transport polymers based on PMPSi were studied. Efficient blue light- emitting devices (LEDs) with an air-stable electrode based on polymer blends composed of SPPP and PMPSi have been fabricated. In contrast to LEDs made of neat SPPP, an increase in external EL efficiency and improvement of the stability of blue emission were achieved in these LEDs. This enhancement is far above the increase in the PL efficiency of the blend layers. New alternately substituted poly(p- phenylene)s with high photoluminescent efficiency and new polymers with (pi) -conjugated or electron-transporting moieties attached to the polysilane backbone were synthesized.

Study of Macromolecular Chain Dynamics in Polymer Complexes by Time-Resolved Fluorescence Spectroscopy

Poly(methyl methacrylate)s labeled with the anthracene fluorophore were prepared by free radical, anionic, and coordination polymerization yielding atactic and syndiotactic polymers. Unlabeled isotactic poly(methyl methacrylate) was prepared by anionic polymerization. Time-resolved fluorescence spectroscopy was used to study polymer association in solution. The time-dependent decays of fluorescence anisotropy show that stereocomplexation causes an increase in rotational correlation times of anthracene fluorophores both embedded in the polymer backbone and attached at the end of the side chain of polymer molecules. The rotational correlation time of anthracene fluorophore in dimethylformamide as a part of stereocomplex is 11.9 and 30 ns in the side chain and embedded in the polymer backbone, respectively, and shorter than 3 ns in noncomplexing solvent.