Pyrene functionalized triphenylamine-based dyes: synthesis, photophysical properties and applications in OLEDs

Pyrene functionalized triphenylamine-based dyes TP, TCP and TCCP were synthesized via alternate Heck and Wittig reactions. It was found that they could emit strong green light with high fluorescence yields because the formation of the excimer from a pyrene unit was suppressed completely. Moreover, the nondoped organic light-emitting diodes using TP, TCP and TCCP as the emitters as well as the hole-transporting materials were fabricated, and gave green electroluminescence. Notably, the device based on TP exhibited good performance with a low turn-on voltage of 2.80 V, a high maximum luminance of 29 880 cd m−2 at 9.5 V, a high current efficiency of 3.34 cd A−1, and a high power efficiency of 2.67 lm w−1. It suggested that pyrene functionalized triphenylamine derivatives may have applications in non-doped OLEDs.