Enhancing Optical Microcavities with TDBC J-aggregates

This study demonstrates the integration of a J-aggregate into all-polymer microcavities. J-aggregates are increasingly researched thanks to their peculiar optical properties characterized by sharp and intense absorbance and photoluminescence signals.1 To this end, we exploit a class of planar one-dimensional photonic crystals, known as distributed Bragg reflectors (DBRs), as building blocks of the microcavity architecture. These structures consist of a periodic stacking of dielectric materials’ bilayers with different refractive indexes that give rise to light frequencies whose propagation is forbidden within the structure. These frequencies take the name of photonic bandgaps (PBGs).2 Introducing an engineered defect layer within the lattice generates cavity modes, specific frequencies within the PBG where light propagation is allowed.2 An example of the structure is reported in Figure 1. In principle, when a dye is embedded into the microcavity defect, its photoluminescence cannot propagate at the PBG wavelengths, and all photons are redistributed within the cavity mode. In this work, we report on the effect of spun-cast poly(N-vinylcarbazole) (PVK) – Aquivion® (AQ) microcavities on the emission properties of TDBC (Figure 1) which results in highly emissive optical structures with enhanced spectral selectivity with respect to those fabricated with standard organic emitters. These results offer new promising opportunities for improving the performances and versatility of photonic devices. Indeed, the ease of spectral tuning of the microcavity optical properties makes them promising tools for a variety of technological applications including sensing, lasing, and optical communication.