Fig. 3: Formation of chiral Frenkel excitons in the hybrids of the chiral plasmonic 432 helicoid IV NPs and TDBC aggregates.

a Extinction CD spectra of the (D-432 helicoid IV NP)–(TDBC aggregate) hybrid films varying from the chiral-plasmon- to chiral-exciton-like feature as the initial n_TDBC was increased during the hybrid film preparation. The size of the chiral NPs is D = 150 nm. n_TDBC = 0, 18.5, 37, 55.5, 74, 111, 150 and 185 nmol for lines i–viii, respectively. The red arrows show the enlarged CD splitting signals with the increased TDBC amount. b–d Extinction CD spectra of the (differently sized L-432 helicoid IV NP)–(TDBC aggregate) hybrid films exhibiting different features. The gray lines show the extinction band of TDBC. The hybrid film composed of the NPs with D = 150 nm and high n_TDBC exhibits the chiral-exciton-like feature (b). The hybrid films composed of the NPs with D = 100 nm (c) and D = 210 nm (d) and moderate n_TDBC exhibit the chiral plasmon–exciton coupling feature. e Energy diagram of the chiral excitons in TDBC J-aggregates derived from the CD and CPPL spectral measurements. f Extinction dissymmetry factor spectrum (blue line) and fluorescent g_PL spectrum (red line) of the (D-432 helicoid IV NP)–(TDBC aggregate) hybrid film. g Extinction dissymmetry factor spectrum (blue line) and fluorescent g_PL spectrum (red line) of the (L-432 helicoid III NP)–(TDBC aggregate) hybrid film. The SEM images and g_ext spectra of the 432 helicoid IV NPs were shown in Supplementary Fig. 12. Source data are provided as a Source Data file.