Use of poly(phenyl quinoxaline) as an electron transport material in polymer light-emitting diodes

Abstract

We report the use of a poly(phenyl quinoxaline) (PPQ) as an electron transporting conjugated polymer for electroluminescence (EL) applications. Single‐layer PPQ devices with ITO anode and aluminium cathode show unipolar electron transport with current densities up to 60 mA/cm² but no emission. Two‐layer structures combining PPQ as electron transport material with the hole transporting poly(2,5‐dialkoxy‐p‐phenylene vinylene) (PDAOPV) show strong emission from the PDAOPV with brightnesses up to 250 cd/m². These two‐layer structures have a maximum EL quantum efficiency of 0.35% which is ten‐fold enhanced compared with the corresponding single‐layer PDAOPV devices.