SYNTHESIS AND PROPERTIES OF NOVEL HOLE TRANSPORT MATERIALS FOR ELECTROLUMINESCENT DEVICES

We synthesized low molecular weight triphenyldiamines (TPDs), novel 1, 3,5-tris(diarylamino)benzenes (TDABs), polymeric triphenyldiamines and insoluble triphenylamine networks based on tris(4-ethynylphenyl)amine as hole transport materials for electroluminescent displays. The HOMO energy values as determined from cyclic voltammetry measurements for TPDs and TDABs are between -4.97 and -5.16 eV. By using a polymeric TP D as hole transport layer and tris(8-quinolinolato) aluminium as emitt er, LEDs with an onset voltage of 3V and a luminance up to 900 cd/m(2) were obtained under ambient conditions.