A series of novel arylvinylene substituted phenanthroline derivatives has been synthesised and their application as electron transporting materials in organic light emitting diodes (OLEDs) has been investigated. One particular derivative, namely, 2,9-bis-(2-thiophen-2-yl-vinyl)-[1,10]phenanthroline (C-4) shows significantly lower operating voltage (36% reduction) and increase of power efficiency of up to 83% compared to tris (8-quinolinolato)aluminium (III) (Alq3). C4 also shows substantially longer (nearly 6-fold) life-time than bathophenanthroline (BPhen) in blue devices. Doping of C4 with electron donors such as m-MTDATA, a-NPB and lithium quinolinolate (Liq) further reduces the turn-on voltage and operating voltage.
- organic light emitting diodes
- arylvinylene phenanthroline
- electron transport