Performance of a polymer light-emitting diode with enhanced charge carrier mobility

The device characteristics of a polymer light-emitting diode (PLED) based on a poly(p-phenylene vinylene) (PPV) derivative with an enhanced charge carrier mobility have been investigated. Improvement of the mobility, which has been obtained by a decrease of the energetic disorder in the polymer, is expected to increase the power efficiency of a PLED. However, it is demonstrated that an increased mobility leads to a decrease as well as to a slower rise of the quantum efficiency with voltage. This performance reduction is explained in terms of an increased quenching of the electroluminescence (EL) at the cathode.