Synthesis and Light-Emitting Properties of Bipolar Oligofluorenes Containing Triarylamine and 1,2,4-Triazole Moieties

A facile approach for synthesis of bipolar oligofluorenes, TAZ-OF(n)-NPh, n = 2 or 3 end-capped with hole-transporting diphenylamino and electron-transporting triazole moieties by Suzuki cross-coupling as the key reaction has been developed. This novel bipolar oligofluorenes exhibited blue-emission, high thermal and morphological stabilities. The single-layer OLED based on TAZ-OF(2)-NPh exhibited superior device performance with a maximum luminance of 1128 cd m-2 and luminance efficiency of up to 0.83 cd A-1.