Enhanced Optical Response Observed at CsPbX₃ Nanocube/m-TiO₂/Au Micro-Pyramid Interface

CsPbX₃ perovskite nanoparticles have attracted the attention of many researchers due to their brilliant luminescence, broad color tunability and facile synthesis. The behavior of any layered optical device is regulated by the properties of its interface(s). This makes in-depth studies of the response to impinging photons at these interface(s) extremely valuable. In this presentation the optical reflection spectroscopy response at the interface of CsPbBr_3-xA_x (A=Cl, I) nanocubes with a plasmonic nanostructure is discussed. CsPbBr_3-xA_x (A=Cl, I) nanocubes, emitting in the red, green and blue wavelengths, were synthesized via a Schlenck line and hot injection method. The resulting nanocubes were roughly 7.2 nm in length along the side as measured by transmission electron microscopy. The plasmonic nanostructure consisted of a mesoporous anatase-TiO₂ thin film coated on top of Au micro pyramids, which exhibit signatures of surface plasmon polaritons. Prominent peaks are observed in the reflection spectroscopy measurements at the interface between nanocubes and plasmonic nanostructure, which suggests there is a combination of SPP-Exciton, Phonon-Exciton, Photon-Exciton coupling and surface diffraction occurring at these interfaces.