New Oxadiazole-Containing Conjugated Polymer for Single-Layer Light-Emitting Diodes

Poly(phenylenevinylene)s (PPVs) containing rigid oxadiazole units as main chain substituents were synthesized. The electron-deficient oxadiazole moieties are directly attached to the phenyl rings of PPVs to increase the electron-injection properties of the polymers. In addition, the near-orthogonal arrangement of the PPV backbone and the oxadiazole units helps to limit the π-stacking of the emissive units, thus increasing the radiative decay quantum yield and photostability of the polymer. These polymers have shown good electron injection/transport ability and luminescence properties. Single-layer LED devices with the configuration ITO/polymer/Al show external quantum efficiencies up to 0.045%.