Simple and Versatile Platforms for Manipulating Light with Matter: Strong Light–Matter Coupling in Fully Solution‐Processed Optical Microcavities

Abstract

Planar microcavities with strong light–matter coupling, monolithically processed fully from solution, consisting of two polymer‐based distributed Bragg reflectors (DBRs) comprising alternating layers of a high‐refractive‐index titanium oxide hydrate/poly(vinyl alcohol) hybrid material and a low‐refractive‐index fluorinated polymer are presented. The DBRs enclose a perylene diimide derivative (b‐PDI‐1) film positioned at the antinode of the optical mode. Strong light–matter coupling is achieved in these structures at the target excitation of the b‐PDI‐1. Indeed, the energy‐dispersion relation (energy vs in‐plane wavevector or output angle) in reflectance and the group delay of transmitted light in the microcavities show a clear anti‐crossing—an energy gap between two distinct exciton‐polariton dispersion branches. The agreement between classical electrodynamic simulations of the microcavity response and the experimental data demonstrates that the entire microcavity stack can be controllably produced as designed. Promisingly, the refractive index of the inorganic/organic hybrid layers used in the microcavity DBRs can be precisely manipulated between values of 1.50 to 2.10. Hence, microcavities with a wide spectral range of optical modes might be designed and produced with straightforward coating methodologies, enabling fine‐tuning of the energy and lifetime of the microcavities‘ optical modes to harness strong light–matter coupling in a wide variety of solution processable active materials.

Optical Cavity Design and Functionality for Molecular Strong Coupling

“…Alternatively, the DBR mirror can be manufactured through the dip‐coating of two types of polymer layers. Recently, the solution‐processed fabrication of DBR mirrors has been demonstrated [35] . This alternative method involves the alternating lamination of a high‐refractive‐index titanium oxide hydrate/poly(vinyl alcohol) and a low‐refractive‐index fluorinated polymer, which enables the creation of the DBR mirror.…”

Polarization-Dependent Strong and Weak Light-Matter Coupling in Aligned Perylene Diimide Thin Films

“…Here, we investigate aligned thin films of the well-known n-type semiconductor and fluorophore PDIF-CN 2 ( N , N ′-bis(1 H ,1 H -perfluorobutyl)-dicyanoperylene-3,4:9,10-bis(dicarboximide)) integrated in silver-clad Fabry–Pérot microcavities. PDIF-CN 2 is a member of the large family of perylene diimides (PDI), whose strong optical transitions and high photostability have led to their application in various exciton–polariton devices including polariton lasers. ,− Several PDIs can form J-aggregates in the solid state, whose sharp absorption bands and strong photoluminescence (PL) can be especially useful for polaritonic applications. , PDIF-CN 2 combines these advantageous properties with the potential for high molecular alignment in thin films and good charge transport. ,, When deposited as an aligned thin film by zone-casting, PDIF-CN 2 exhibits molecular packing with both J-like and H-like aggregate behavior depending on light polarization …”

Optical and physical properties of zirconium dioxide reinforced poly(methyl methacrylate) nanocomposite films

“…A recent study by Strang et al prepared a sandwich like structure of low RI polymer and high RI titanium dioxide hydrate-PVA, where in they were able to tailor the refractive index between 1.5 and 2.10 by adjusting the microcavity distributed Bragg reflectors. 11 Similarly, the light management in an LED inside its layers can be effectively be carried out by controlled altering of the refractive indices of the layers. In fact the refractive index mismatch plays a critical role in controlling the haze and light scattering.…”