Transient electroluminescence study of mobility balancing in organic light-emitting diodes based on poly(p-phenylenevinylene) derivatives

Transient electroluminescence (EL) measurements were carried out on organic light-emitting diodes based on poly(p-phenylenevinylene) (PPV) derivatives. As a result, in contrast to the case of a PPV derivative carrying a hole-transporting moiety, the much improved external quantum efficiencies for the device based on a PPV derivative carrying an electron-transporting moiety were explained by the enhanced EL lifetime arising from the electron–hole mobility balancing.