MEASUREMENT OF THE ENERGY-GAP IN SEMICONDUCTING POLYMERS USING THE LIGHT-EMITTING ELECTROCHEMICAL-CELL

The light-emitting electrochemical cell (LEC) is used to measure the c harge injection energy gap in semiconducting polymers. Simultaneous me asurements of the onset of electrochemical doping, electrical injectio n, and electroluminescence from light-emitting electrochemical cells d etermine the magnitude of the exciton binding energy; the LEC data are consistent with the semiconductor model in which the exciton binding energy is small.