Tandem white OLED with low driving voltages using a novel electron transporting material

We demonstrate high performance blue, yellow and tandem white organic light-emitting diodes with low driving voltages using a novel electron transporting material. The blue and yellow OLEDs achieve low turn-on voltage of 2.6 V and 2.2V, respectively, equivalent to their energy gaps. The tandem white OLED shows an extremely low driving voltage of 5.9 V at 1000 cd/m2, together with an efficacy of 28.6 lm/W, a current efficiency of 53.7 cd/A, and an external quantum efficiency of 24.6%. A 64 × 64 mm2 panel has been produced with the same architectures as the tandem OLED pixel, the efficiency is further improved to 45 lm/W with the use of a micro-lens film.