  Conversion of pure spin current to charge current in single-layer graphene
(SLG) is investigated by using spin pumping. Large-area SLG grown by chemical
vapor deposition is used for the conversion. Efficient spin accumulation in SLG
by spin pumping enables observing an electromotive force produced by the
inverse spin Hall effect (ISHE) of SLG. The spin Hall angle of SLG is estimated
to be 6.1*10-7. The observed ISHE in SLG is ascribed to its non-negligible
spin-orbit interaction in SLG.
