  We study electron correlation driven superconductivity on a decorated
honeycomb lattice (DHL), which has a low-energy flat band. On doping, we find
singlet superconductivity with extended-s, extended-d and f-wave symmetry
mediated by magnetic exchange. f-wave singlet pairing is enabled by the lattice
decoration. The critical temperature is predicted to be significantly higher
than on similar lattices lacking flat bands. We discuss how high-temperature
superconductivity could be realized in the DHL materials such as Rb3TT. 2 H2O
and Mo3S7(dmit)3.
