Large-scale preparation of highly conductive three dimensional graphene and its applications in CdTe solar cells

High-yield three dimensional (3D) graphene networks were prepared on Ni foams by ambient pressure chemical vapour deposition (APCVD). The layer number of graphene can be tuned by changing the gas flow ratio and growth time. The assembled films from the vacuum filtration of the 3D graphene possessed excellent electrical transport properties (R-s similar to 0.45 Omega/sq, sigma similar to 600 S cm(-1)), superior to the reported graphene and carbon nanotube films. Highly conductive films as back electrodes of CdTe solar cells significantly improved the photovoltaic efficiency (9.1%).