Observation of strong exciton–photon coupling in an organic microcavity in transmission and photoluminescence

An optical organic semiconductor microcavity in the strong coupling regime containing J-aggregates (1,1′-diethyl-2,2′-cyanine (PIC)) as optically active material has been investigated. Stable thin layers of homogeneously distributed aggregates were prepared by spin-coating of a specific salt of this dye [(PIC+)2B10H102−] without the need of a polymer matrix. Transmission and photoluminescence measurements reveal an anticrossing that is typical for the strong coupling regime. Compared with inorganic semiconductors, a large Rabi splitting of approximately 25 meV was observed in the transmission and photoluminescence measurements.