Study of charge conduction in a poly(p-phenylenevinylene) derivative carrying an electron-transporting moiety

Recently, we have reported transient electroluminesence (EL) measurements in an organic light-emitting diode based on a poly(p-phenylenevinylene) (PPV) derivative carrying an electron-transporting moiety, poly[(2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxdianzole)-p-phenylenevinylene] (PPPDPV), in order to investigate the mechanism of the enhanced external quantum efficiency. In this work, we have carried out J-E (I-V) characteristics measurements in EL devices based on PPV and PPPDPV, respectively, which revealed a space-charge limited conduction (SCLC) with exponential trap distribution mechanism in both. The trap densities of majority carrier were calculated from the J-E (I-V) curves and were compared with the EL external quantum efficiencies.