Electroluminescence and fluorescence emission of poly(n-vinylcarbazole) and poly(n-vinylcarbazole)-Ir(ppy)3-based organic light-emitting devices prepared with different solvents

Abstract. We present a study of spectroscopic proprieties of poly(n-vinylcarbazole) (PVK) and PVK doped with iridium complexes tris[2-phenylpyridinato-C2,N]iridium(III) (Ir(ppy)3) films prepared by spin-coating from toluene and chlorobenzene solutions. A different molecular organization of the polymer on the substrate during the spin-coating process can be produced using solvents with different boiling temperatures. 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 fluorescence emissions properties have been studied, for pure PVK and PVK doped with different weight percentage of Ir(ppy)3. Different organic light-emitting devices, using a simple architecture, have been prepared with both solvents to test the change in electroluminescence spectral shape and in electrical characteristic, and the final efficiencies of the devices have been evaluated.