Twin derivatives of 3-arylcarbazoles as efficient hole transporting amorphous materials

Twin derivatives of phenyl, biphenyl or naphthyl substituted carbazoles were synthesized by the multi-step synthetic routes. Morphological transitions and hole injecting properties of the materials were examined by differential scanning calorimetry and electron photoemission technique respectively. Hole-transporting properties of the derivatives were tested in the structures of organic light emitting diodes with Alq3 as the green emitter. The device based on a twin derivative composed of 3-(1-naphthyl)carbazol-9-yl blocks exhibited the best overall performance with a maximal photometric efficiency of 3.4 cd/A and maximum brightness of about 7940 cd/m2.

► Twin derivatives of 3-arylcarbazoles were synthesized. ► These compounds used as hole-transporting materials in OLEDs. ► Efficiency of 3.4 cd/A and brightness exceeding 79,400 cd/m2 were obtained.