Charge distribution in light emitting electrochemical cells

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 and ionic molecules) in the d evice; We report on the local ion distribution of lithium and triflate ions in a blend of the ionic conducting polymer poly (ethylene:oxide) (PEO) and the conjugated polymer m-LPPP (methyl substituted poly (para phenylene)) b y secondary ion mass spectroscopy(SIMS). In the system ITO/active layer/Al the ions are found to be located close to their counter electrodes. The beh avior of these devices is investigated by impedance spectroscopy.