The　absorption　spectra　and　input　photon-to-converted　current　efficiency　curves　showed　that　Au　nanoparticles　increased　the　plasmonic　broadband　light　absorption,　thereby　enhancing　the　short-circuit　current　density　of　the　inverted　organic　photovoltaic　(OPV)　cells　with　a　Au-ZnO　nanocomposite　electron　transport　layer　(ETL).　The　power　conversion　efficiency　of　the　inverted　OPV　cell　fabricated　with　a　Au-ZnO　nanocomposite　ETL　was　higher　by　40%　than　that　of　the　inverted　OPV　cell　fabricated　with　a　ZnO　nanoparticle　ETL,　which　could　be　attributed　to　the　enhanced　photon　absorption　in　the　active　layer　due　to　the　localized　surface　plasmonic　resonance　of　the　Au　nanoparticles.　©　2015　The　Japan　Society　of　Applied　Physics.