Bilayer graphene anode for small molecular organic electroluminescence

Abstract

We demonstrate that bilayer graphene can be used as the anode of a small molecule organic light-emitting diode (OLED). In our OLEDs, bilayer graphene was used as the anode, Sm/Au as the cathode and Alq3 as the emitter. By applying Cs2CO3-doped 4,7-diphenyl-1,10-phenanthroline to partly substitute Alq3 as the electron injection and transport layer, the electron current injected from Sm/Au was enhanced to match the hole current injected from the bilayer graphene anode and consequently improved the light emission efficiency. The maxima of luminance efficiency and power efficiency reached 1.18 cd A−1 and 0.41 lm W−1, respectively. We think that the efficiency of the bilayer graphene anode OLED can be further optimized by finding a more efficient electron injection and transport layer and/or reducing the hole density of the graphene anode.