Ternary Assemblies of TADF Core/TDBC-J-Aggregate Shell Nanoparticles and d/l-Phenylalanine-Based Nanohelixes for Circularly Polarized Luminescence

Developing pure organic nanostructures with circularly polarized luminescence (CPL) response is of high interest for the community. As ordered nanoassemblies of a conjugated dye, the J-aggregate exhibits an ultra-narrow emission bandwidth, a high radiative rate, and a largely red-shifted emission but has been rarely employed for constructing a CPL system due to the minimized Stokes shift and the rigorous condition of assembling. In this work, we developed a simple strategy of ternary co-assembling to facilitate narrowband CPL response of cyanine J-aggregates, in which J-aggregate emitters were co-assembled as a shell of light harvester nanoparticles to form the core–shell structures in the nanoscale. Taking advantage of the core–shell energy transfer (FRET) and chiral transfer from assembled nanohelixes to J-aggregate emitters, the narrowband (fwhm <10 nm and centered at ∼585 nm) CPL response of TDBC-J was demonstrated with a dissymmetric factor glum of ±1 × 10–3. Our work provides a simple approach to facilitate narrowband CPL response from J-aggregates in an aqueous solution, which might be able to offer opportunities to achieve CPL response in a greatly red-shifted even near-infrared regime with potential applications.