Solvent effects on spectral emission of PVK and PVK-Ir(ppy)3 based OLEDs

In this work we have compared the effect of using solvents with different boiling temperature on the spectroscopic emission proprieties of poly(n vinylcarbazole) (PVK) and PVK doped with Iridium complexes tris[2-phenylpyridinato-C2,N]iridium(III) (Ir(ppy)3) films, due to the different organization of the polymer on the substrate during the spin coating process. The modified molecular rearrangement affects the emission properties of the PVK material and the consequent energy transfer to the doping molecules. Both Static and dynamic emissions proprieties have been studied, for the case of pure PVK and PVK doped with different weight percentage of Ir(ppy)3. Different devices have been prepared to test the change in electroluminescence spectral shape and in electrical characteristic and the final efficiencies of the devices have been evaluated.