Plasmonic nanocavity enhanced luminescence for in-plane and out-of-plane excitons in $${\text{BA}}_{2} {\text{PbI}}_{4}$$ Ruddlesden Popper perovskite thin film

In this work, we propose an easy-to-fabricate plasmonic cavity design to enhance luminescence from $${\text{BA}}_{2} {\text{PbI}}_{4}$$ Ruddlesden Popper thin films, which otherwise suffer from a very low quantum yield due to strong exciton-phonon interactions in the lattice. We designed a nanoparticle on mirror plasmonic cavity using 3D-finite-difference time-domain simulations, with perovskite film sandwiched between the two metallic structures yielding a 7-fold local enhancement in photoluminescence for intralayer excitons emitting at 520 nm. The designed cavity also aids the detection of interlayer excitons at 540 nm, for which a huge PL enhancement of more than 1500 times is easily obtained.