Process dependence of morphology and microstructure of cyanine dye J-aggregate film: correlation with absorption, photo- and electroluminescence properties.

Cyanine dye J-aggregate films are a class of absorbing and luminescent materials which have been extensively applied in the polariton-based research. Here we systematically study the DEDOC cyanine dyes J-aggregate films made by layer-by-layer assembly and spin-coating processes to establish a clear correlation between the film structure and the absorption and luminescence properties. From detailed analyses of morphology, optical spectra, and light-emitting diode characteristics, we demonstrate that layer-by-layer assembled film has higher degrees of homogeneity and molecular packing quality than spin-coated film, leading to a higher absorption coefficient, more uniform luminescence, and a greater electroluminescence quantum efficiency with maximized thickness.

Adjustable exciton-photon coupling with giant Rabi-splitting using layer-by-layer J-aggregate thin films in all-metal mirror microcavities.

Developing of highly absorbing thin films is essential for exploration of light-matter interaction and polariton-based applications. We demonstrate here layer-by-layer assembled J-aggregate thin films of (DEDOC) cyanine dyes that have high absorption coefficient and controlled thicknesses, leading to adjustable exciton-photon coupling and Rabi splitting exceeding 400 meV at room temperature in all-metal mirror microcavities.