Photoinduced, interfacial charge separation across a gold nanoparticles-sensitized solid-state heterojunction by means of transient absorption laser spectroscopy is first reported: charge is separated by that electron transfer from the excited gold particle to TiO 2 and that from a donor to the gold particle. Based on this charge separation, solid-state gold nanoparticles-sensitized photovoltaic cell is successfully achieved using polyethylene oxide (PEO) filled with TiO 2 instead of a liquid electrolyte. As a low-cost solid-state photovoltaic cell, its incident photon to current conversion efficiency (IPCE) was achieved to be ∼6% with PEO filled with TiO 2 nanoparticles containing the optimized redox couples of I − /I3-. The stability of the photovoltaic cell was proved to be relatively long.