We present the electrical and optical characteristics of a single-ion transport light-emitting electrochemical cell (SLEC) based on poly(p-phenylene vinylene) (PPV) derivative containing aryl-substituted oxadiazole in the backbone (MEH-OPPV). Tonized polyurethane-poly(ethylene glycol) (PUT) used as polymer electrolyte is introduced into the active layer of the SLEC. The turn-on voltage of the SLEC is about 3 V according to its current density-voltage (J-V) characteristics. The response time of the SLEC is less than 10 ms, lower than that of normal LECs by two orders of magnitudes roughly. The reasons of the quick response for the SLEC are discussed in the article. (c) 2006 Wiley Periodicals, Inc.