[6,6]-phenyl C61, butyric acid methyl ester-polymer nanocomposite: a good material platform for organic light-emitting diodes.

PCBM-polymer nanocomposites [[6,6]-Phenyl C61 butyric acid methyl ester (PCBM):Poly(9-vinylcarbazole) (PVK)] were prepared by dissolving them in chloroform. Photophysical properties were studied first, and then the hole-only devices were fabricated to study the hole-transporting properties. The specially designed organic light-emitting diodes (OLEDs) with the structure of indium tin oxide (ITO)/PCBM:PVK (x wt%, approximately 40 nm)/4,4'-bis(2,2'-diphenylvinyl)-1,1'-biphenyl (DPVBi) (30 nm)/Tris-(8-hydroxyquinoline)aluminum (Alq3) (30 nm)/lithium fluoride (LiF) (1 nm)/Al were fabricated to verify the transport properties of the nanocomposites. Finally, the nanocomposites were applied in the Alq3-based OLEDs as a hole-transporting layer. A significant improvement was observed in OLEDs when the nanocomposites were used to replace the conventional pristine PVK.