Plasmonic metal nanostructures provide a promising strategy for light trapping and therefore can dramatically enhance photocurrent in optoelectronics only if the trapped light can be coupled effectively from plasmons to excitons, whereas the reverse transfer of energy, charge, and heat from excitons to plasmons can be suppressed. Motivated by this, this work develops a scheme to implement a metafilm with Ag nanoparticles (NPs) embedded in 10 nm thick silica (Ag NPs-silica metafilm) to the active device channel of a hybrid perovskite film/graphene photodetector. Remarkably, an enhancement factor of 7.45 in photoresponsivity, the highest so far among all the reports adopting plasmonic metal NPs in perovskite photodetectors, has been achieved on the photodetectors with the Ag NPs-silica metafilms. Considering that the synthesis of the Ag NPs-silica metafilms can be readily scaled up to coat both rigid and flexible substrates, this result provides a low-cost metaplatform for a variety of high-performance optoelectronic device applications.
Keywords: metafilms; metal nanoparticles; perovskite; photodetectors; plasmonic effect.