High performance organic light-emitting diodes based on tetra(methoxy)-containing anthracene derivatives as a hole transport and electron-blocking layer

A series of 2,3; 6,7-tetra(methoxy)-9,10-di(aryl) anthracene derivatives have been readily synthesized by acid-catalyzed Friedel-Crafts alkylation of aromatic aldehydes with veratrole. These compounds have good thermal and morphological stability. Their highest occupied molecular orbital (HOMO: -5.23-5.28 eV)/lowest unoccupied molecular orbital (LUMO: -2.11- -2.28 eV) energy levels are energetically favorable for use as hole-transporting/electron-blocking layers in organic light-emitting devices (OLEDs). Device performance of these non-amine based hole-transporting materials were comparable to or better than that of the traditional arylamine derivative NPB. The optimized green doped three-layer device based on 2,3; 6,7-tetra(methoxy)-9,10-di(1-naphthyl) anthracene (TMOADN) exhibited a current efficiency of 25.6 cd A(-1) (13.4 lm W(-1)) at 20 mA cm(-2) with an external quantum efficiency of 7.05%.