Turn on behavior of light emitting electrochemical cells

In light emitting electrochemical cells (LECs) the turn on voltages both fo r current and electroluminescence depend on different parameters, like the polymer energy gap or the dissociation free energy of the salt We report in vestigations of the behavior of salt dissociation in blends of optimized LE Cs, where the luminescent and the ionically conducting polymer form a heter ogenous morphology in order to improve the response times of the LECs and p resent the results of infrared measurements (IR) on the active layer of the se LECs. We compare them with results of infrared measurements of the activ e layer of LECs where short ethylene oxide side chains are attached on the backbone of the conjugated polymer in order to investigate the kind of ioni c species being present.