Researchers from Purdue University discovered a while that using silver nanowires can dramatically increased graphene's conductivity. The nanowires are used to bridge defects and crystal boundaries. Now researchers from the University of Texas demonstrated how this works.
When making large graphene sheets, there are many defects (ripples, folds and tears) and also large graphene sheets are currently made from many small crystals, and the boundaries between the crystals scatter the electrons. The Texas researchers grew graphene on copper foil using CVD. This sheet had a resistance of over 1,000 ohms. Transferring a film of silver nanowires to the graphene sheet lowered the resistance to 64 ohms. The sheet still retained good transparency (94%). A bi-layer graphene-silver-nanowire sheet resulted in lower resistance (24 ohms) - and 91% transparency.