Thep-i-njunction in a polymer light-emitting electrochemical cell (LEC) is stabilized by cooling the device below the glass transition temperature of the ion-transport polymer. LECs with frozenp-i-njunctions exhibit typical light emitting diode (LED) behavior including diode rectification, unipolar light emission (same polarity as that used for generating the junction), and fast response. The freezeout of ion motion allows polymer LECs to be driven at bias voltages well beyond the electrochemical stability window, and thereby extends the potential applications of polymer LECs to high pixel density, column-row addressable displays. ©1997 American Institute of Physics.