Local ions distribution inhomogeneities in polymer based light emitting cells

In the last years the development of light emitting electrochemical cells o n a polymer base has made a great pr ogress. They are extremely interesting due to their low cost, but Still, problems concerning the stability and li fetime of these elements remain. The performance of light-emitting electrochemical cells (LEC) is strongly i nfluenced by the inhomogeneous distribution of the three main components (l ight emitting polymer, ion conductive polymer, ionic molecules) in the devi ce. The local ions distribution of lithium and triflate (Short for the CF3S O3- species) ions in a blend with the ionic conducting polymer poly(ethylen e oxide) (PEO) and the conjugated polymer m-LPPP (methyl substituted poly(p ala phenylene)) throughout the polymer layer has been investigated by secon dary ion mass spectroscopy (SIMS). Different combinations of top- and base- electrodes have been investigated and have been found to influence the dist ribution of the ions strongly.